Staircases are strong things. They are almost impossible to break in normal use, they do not generally suffer from rot, and as a rule the worst that can happen to them is that the handrail comes loose or some of the steps start to creak.

Here is how to deal with both these faults, and some others. Staircases are not difficult to repair. But it is essential first to know how they are constructed, because nearly every part of a staircase supports, and is supported by, some other part. And if you remove the wrong part you may easily bring the whole structure crashing down. All wooden staircases are fairly alike in construction, but there are three main types.

The closed-string staircase is the cheapest type, easier to make and repair and generally found in newer houses. The cut string staircase is better looking but more complicated and expensive to build. It would typically be found in a house built before the first world war. The open riser staircase is built like a step-ladder, with treads but no risers. It is most commonly found in open-plan architecture. The closed-string staircase The main load-bearing components of a closed-string staircase are the strings or stringers, a pair of straight-sided pieces of wood running up each side of the staircase. The treads and risers (horizontal and vertical parts of the steps) are fastened into the strings by housing joints.

Most staircases run along a wall, and have one wall string, which is solidly fastened to the wall and is about 29mm thick, and one outer string, which has to be stronger and so is about 35mm thick. The outer string is held in place by being inserted into the vertical newel posts, one at each end of each string, by a set of large angle mortise and- tenon joints. The newel posts are bolted strongly to the floor joists.

A quick, easy and solid way to repair a staircase

Some staircases are completely free-standing and have ‘outer’ strings on both sides. Others have a wall on both sides and two wall strings. But in both cases, the rest of the construction is completely normal. There are two main methods of treads and riser construction. They can be tongued-and grooved together, in which case it is impossible to remove one tread without dismantling the entire staircase.

Or they can be screwed together, in which case it might just be possible to remove and replace one tread from below-though it would involve chiselling out the rear of the housing and a lot of other arduous work. The screwed construction is not as strong as the tongued and grooved method. The joint between each tread and the riser below it is reinforced by a triangular glue block with 76mm long screws passed through it. These blocks are, of course, used only in the inside angles on the underside of the step. If they were used on the top they

would get in the way of your feet. The method by which the treads and risers are held firmly to the strings is found only in stair construction. They are jammed into their housings by narrow wedges driven along the groove of each housing, so that they are held firmly against the upper side of the housing. The lower side of the housing, against which the wedge rests, is cut at a slant to accommodate it. The purpose of this wedging is to jam each tread and riser so firmly in place that it cannot rock or creak.

If a stair creaks, it is generally a sign that the wedges have come loose under it. The bottom step of a flight of stairs generally projects beyond the newel post. It is normally a completely separate unit from the rest of the stairs, and can be levered off without much difficulty if, for example, you want to repair the floorboards near it. Vertical balusters are set in mortises in the top of the outer string to support the handrail. The tops of the balusters are sometimes inserted in mortises under the handrail, sometimes nailed or fastened by brackets into a groove cut all along the underside of the rail.

The ends of the handrail are strongly fastened to the newel posts, generally by a mortise-and-tenon joint unless the hand rail is a curved decorative one of the type found in many old houses. If there is a handrail on the wall side of the stairs, it is generally just fastened to the wall on brackets, and plays no part in the construction of the stairs. Sometimes there is a newel post fastened to the wall at the bottom to match the one on the outer string. It is just decorative, however, and can be removed if necessary.

Removing the real, outer newel post would deprive the outer string of its support and might easily cause the whole flight to collapse. The cut-string staircase In a cut-string staircase, the wall string is the same as that of a closed-string staircase. The outer string, on the other hand, is completely different. It is cut away to the profile of the treads and risers. The treads rest on it, instead of being housed into it. They are finished with decorative end mouldings that project a short way beyond the string, which gives the outer side of the staircase a very elegant appearance. The risers are mitred into the strings so that no end grain shows.

The balusters are not mortised into the strings, because the tops of the strings are not exposed. Instead, they are inserted in cutouts in the outside ends of the treads, so that their outer sides are flush with the ends of the treads. The outside ol the assembly is covered by the decorative end moulding of the tread, giving the cutout the effect of a mortise. Since the outer string is largely cut away, it is not nearly as strong as a closed outer string. For this reason, there is a strong additional support called a rough carriage running down the centre of the flight.

It consists of a heavy piece of timber, probably 100mm x 50mm, just touching the bottom corner of each step where tread and riser are joined. As an extra support for the treads, timber blocks called rough bracket are screwed to the rough carriage, and reach up from it to the underside of each tread. The word ‘rough’ is used because the assembly is not seen, and does not need to be finished to the same standard as the rest of the staircase.

Obviously, this type of staircase is much more complicated than a closed-string one. The cutting to shape of the outer string, the mitred joints of string and riser, the decorative mouldings on the treads and the rough carriage all take extra work. This explains why a cut-string staircase is seldom found in a modern house. Repairs As you may already have gathered, major structural repairs or alterations to a staircase are out of the province of the amateur handyman, and should only be done by a professional carpenters.

Furthermore, in most countries (including Britain) planning permission is required for all work on the load-bearing parts of a staircase, other than extremely minor renovations. This does not mean that you cannot substantially improve the appearance of a tatty old staircase. But it does outlaw some projects- for example removing the risers to create a modern-looking ‘open tread’ staircase. People quite often attempt to do this, but since the risers contribute to the strength of the stairs, removing them is a recipe for disaster.

Squeaky or loose treads

Treads often squeak when they are stepped on, and it is not a sign that they are about to collapse. But when the problem gets worse, and they can actually be felt to move under your feet, it is time to do something about it. The cause of the problem is nearly always loose wedges.

The glue blocks may be loose as well. Both have to be reached from underneath, however, and this may cause difficulties. Where stairs run above a cellar or a hall cupboard, the underside is exposed and easy to reach. But where the lower side of the stairs can be seen from one of the inhabited parts of the house, it is generally covered with lath and plaster. This must be removed to repair the stairs-a really messy job that covers everyone and everything with plaster dust and the filth of ages from inside the staircase. One consolation for having to perform this unpleasant task is that you can replace the plaster with plasterboard, painted chipboard or tongued-and-grooved boarding.

Next time the stairs need attention, it will be quite simple to remove this covering. Cover everything with dust sheets and rip out the old plaster with a club hammer and bolster. When the dust has settled, look over the underneath and find all the loose wedges. Remove them one at a time and glue them back. If they are shrunken, warped or broken,cut new ones, taking care to copy the slope of the original wedge exactly. Reglue any loose glue blocks and tighten their screws.

Make sure that all surfaces you glue together are clean and dry. If you find a cracked tread, strengthen it with a metal angle bracket screwed to the tread and nearest riser. Newel posts are very firmly fixed and seldom need attention. If they do come loose, take up the floorboards and inspect the way the posts are fastened to the joists. It should be possible to reinforce the joints with wood blocks or steel angle brackets screwed into the corners. Sometimes the mortise-and-tenon joint between the outer string and the newel post becomes loose, loosening all the treads and risers with it. You can’t take it apart, so the only thing to do is to brace it with 32mm square wood blocks glued and screwed into the inside corners. Knocking shallow wedges into the gap might work, but it might also split the newel post if it is not strong.

Replacing the handrail

The only structurally important parts of the handrail and baluster assembly are the newel posts. These should never be removed or weakened, but the rest of the structure is easy to repair or alter. A few years ago people used to dislike the ornamental balusters of old houses, and board them up with hardboard or plywood to create the effect of a solid wall. This type of balustrade may or may not be to your taste, but it does have the disadvantage of making the stairs dark, and thus dangerous, unless they are well lit from above. Today, most people appreciate old balustrades with turned balusters, but if they are in very bad condition, there is no alternative but to take them out and replace them. You might be able to get some more of the same type from a demolition contractor. Otherwise, there is a type of replacement that you can easily make yourself. It looks like a ‘ranch-style’ fence and goes well with most modern furniture, but is not suitable for curved stairs.

The construction differs slightly for closed string stairs (where you will probably want a single rail with the outer string finished to match) and cut-string stairs (where two rails will look better). The first step is to remove the old handrail and balusters, and, in the case of a cut-string staircase, to fill the holes where the balusters fitted. This will present a problem only if the treads are finished in polished wood, which you might have some trouble matching. Glue in small square blocks and plane them flat. Next, box in the newel posts to give them a square section (unless they are square already). Use solid timber, or you will have trouble hiding the edge. Most newel posts have a square base, to which the timber can simply be screwed, but at the top you may have to make a ‘yoke’ out of thick plywood to provide something to screw the timber to. If the newel post is too tall, saw the top off.

Otherwise, put a square block in the top of the ‘box’ and pin it in place from the sides. You can screw a polished hardwood cap to the top of the posts if you like. To box in the outer string of a closed-string staircase. first remove all projections such as electric cables. Then cover the outside of the string with the thinnest timber you can find in the necessary width-or you could use veneered plywood. Cover the inside with a strip of the same material scribed to the shape of the steps. This is a boring job but not difficult. The strips need only be pinned in place, since they are not carrying a load.

Finally, cover the top of the string with a strip to hide the mortises. This strip must be solid wood, because the edges will show. If you have used veneered ply for the sides, the top should be in the same material as the veneer; the idea is to create the appearance of a solid string matching the rails. Finish the new balustrade with a rail or rails made of solid l50mm x 25mm boards screwed to the inside (wall side) of the newel posts. Allow plenty of extra length when buying them, because the ends will be cut at a slant. Of course, there are many other designs for replacement handrails. One that is not recommended is replacing it with a rope. If you stumble and fall against it, it gives outwards and downwards and you tend to go over it head first.

Worn nosings

A nosing is the rounded front part of a tread. On uncarpeted stairs, the nosing wears away, particularly in the middle. Replacing the tread entirely is very difficult and not worth the trouble. A better idea is to cut away the nosing and patch the tread with new wood. Do not cut the wood right back to the riser, or you will weaken the joint there, particularly if it is a tongued-and-grooved joint. The best tool to use for cutting away the old nosing is a spokeshave.

Cut a flat surface, glue a wood strip to it (hardwood is best) and cut the strip to shape with the same tool when the glue is dry. A worn bottom step can be replaced entirely if it is the separate, non-structural kind. But be careful to make the new step exactly the height and width of the old one. If it is different, it will alter the going (slope) of the stairs at the bottom, which might make people trip up at the unexpected change. Finishes If your stairs are structurally sound but covered in tired old paint, you can transform them simply by stripping off the paint.

Scrape off a paint sample and see what kind of wood there is underneath. If it is hardwood, as old stairs often are, you are in luck. Unless it has been stained, which you can discover only by scraping a piece clean, it will look magnificent if it is wax-polished. Even an ordinary softwood staircase will look very good if carefully cleaned and given three coats of polyurethane varnish.

The intricate mouldings of an old staircase are best cleaned with chemical paint stripper (open all windows first!) and a combination shavehook. The treads, risers and strings can be finished with an orbital sander (or less well with a disc sander) when you have removed most of the paint. The rails and balusters must be hand-sanded. If you have a really ornate staircase, and you aren’t frightened of over-decoration, you might even bring out the relief on the mouldings with contrasting paints on the highlights.

Simple and stylish, an open-riser staircase will add a note of distinction to your home. With the right techniques you can build yourself an attractive and streamlined staircase. The building of a glass and metal open-riser staircase is a major construction job which has to be carried out accurately to achieve a good result, as well as to conform to any building regulations that apply in your case.

It is a long and heavy job, and you may need assistance at certain stages. There are two basic designs for open-risers. The most common one is where the steps, or treads, are supported at their ends by strings, timber pieces that run the whole length of the staircase. Housings are cut into the strings to accommodate the treads. In the second design the treads are supported from underneath by means of long timber pieces called spines. For either design a power saw is virtually a necessity and for the first design a power driven router, to cut the housings in the strings that take the ends of the treads, is a great advantage. An alternative method of cutting the housings is, however, given below. An electric orbital sander will considerably simplify the job of finishing the staircase. Hardwood is the ideal timber for the staircase, 250mm x 40mm being a size that will give solid construction.

Softwood can be used, but unless it is an unusually strong type such as parana pine or British Columbian pine, the size should be increased slightly. For example, if common redwood or whitewood is used, a size of is more suitable.

These sizes apply to strings or spines and treads alike, unless the treads are unusually wide. Technical terms You will need to understand a few technical terms when planning your staircase. Going is the horizontal distance between the front edge of one tread and the front edge of the next.

Rise is the vertical distance between the face on one tread and the face of the next. The pitch line is an imaginary line drawn through the top facing edge of each tread. This indicates the angle at which the staircase slopes. Construction requirements In Britain, all new constructions must conform to the requirements laid down in the Building Regulations. In the case of open risers, the requirements are complicated but the basic ones are that: each step must be level, all steps must be of a similar rise, the going of each step must be the same, each step must overlap the next, on a plan view, by 16mm.

In addition to these basic items there are more complex requirements. Sufficient headroom must be provided. Measured vertically from the pitch line, the clearance must be at least 2m to the ceiling. Measured at right angles to the pitch line, the clearance must be at least 1.5m to the ceiling. All staircases must be enclosed on both sides either by two walls or a wa1l on one side and a baluster on the other or balusters on both sides. A baluster or railing, this must be at least 840mm high, measured vertically from the pitch line. At landings the minimum height is 900mm.

In Britain, the Building Regulations also dictate the sizes of the rise and the going. There are two sets of regulations applying to private open-riser staircases, i.e. those in domestic use and ‘common’ open-risers those used in public buildings. Be sure to consult the correct set. For private open riser the minimum going is 220mm and the maximum rise is also 22Omm. In addition, your staircase must conform to a certain formula. The sum of the going of a step plus twice its rise should not be less than 550mm and not more than 700.

The pitch of the staircase will also dictate the rise and going you use. Private open risers must not have a pitch of more than 42′ to the horizontal. Therefore you cannot work to the maximum rise of 220mm and the minimum going of 220mn as this will give you too steep a pitch. It is illegal in Britain to have an open-riser staircase leading to an attic unless there is some alternative means of leaving the attic, such as an external fire escape. There is no simple formula for planning open-riser stairs.

Take all the considerations given above into account when making your dimensional drawing for presentation to your local planning officer. He will tell you whether or not your planned staircase meets all the requirements.

Measuring the stairway

If your open-riser is to replace an ordinary staircase you may be able to use the same dimensions for the new construction as were used for the old. For example, the rise of the old staircase may be suitable to allow you to position the new treads in the same place as the old. You cannot, of course, simply remove the riser from an ordinary staircase to give you an open-riser staircase. This would make the whole structure come loose and fall apart. If the dimensions do not conform, or the staircase is a new feature, then the first step is to measure the overall length of the stairway.

To do this, measure accurately the distance between the floors that the open-riser is to connect. You must make sure that you allow for any slope on the floor, or your height measurement will be out. Make a scaled and dimensioned drawing showing these two levels. Take the maximum permitted rise between one step and another and divide this into the overall rise-the distance between the two floor levels.

This will give you the minimum number of treads you can use. From this, you can calculate the minimum overall going of the staircase -the horizontal distance between one end of the staircase and the other. Once the overall rise and going have been calculated check that the headroom this construction will allow conforms to the regulations. To do this, first mark on the lower floor the position of the bottom of the planned staircase. From this point, to the edge of the upper floor level, stretch a length of string, fixed at the ends with nails. Measure the headroom from this string, both vertically from it and at right angles to it.

Use a steel tape rule to do this. ll the headroom is too tight, reduce the overall going if you can. If there is plenty of headroom, you may wish to increase the size of the treads or decrease the rise between each of them to, ideally, about l90mm. This will make the staircase easier to ascend and descend. Having made these calculations, check that they conform to the formula for private open-risers given earlier. For example, if the overall rise is 2.20m the number of rises will be ten, with an individual rise of 220mm. If the overall going is 2.50m this will give you ten goings at 250mm individual going. Twice the individual rise is 440mm. This, plus one individual going adds up to 690mm. This figure is more than 550mm and less than 700mm so this particular design conforms to the requirements. The final step in ensuring that the staircase conforms to the British Building Regulations is to check the pitch of the staircase. It must not exceed 42″.

You can do this simply by laying a chain-store protractor on your scale drawing. Design considerations There are two basic designs of open-riser staircases. In the first the ends of the treads are housed in channels cut in the strings, or long timber side supports. In the second the treads are supported from underneath by means of spines. Triangular blocks of wood are fixed to the top edge of the spines so that the treads are horizontal. The use of strings gives better fixing for the handrails and balusters-but this is not an insurmountable problem if you want spines. If you design your staircase with spines, you must use more than one spine.

If only one spine is used, the treads would create excessive leverage on the spine if you put your weight on one end of them.

Setting out the tread supports

In both types of staircase, the angles for making out the supports to show the positions of the treads have to be determined. This is done by using similar triangles. A similar triangle is one that has the same angles as another triangle but is larger or smaller than it. In this case, the distance between the treads is estimated by drawing a similar triangle to that formed by the planned pitch of the staircase, the floor and a vertical line to the floor from the upper floor (the one to which the staircase will run).

The two sides of the triangle that meet at right angles should be as long as the planned rise and going of the individual treads. Make a template, sometimes known as a pitch board in this context, to match these sizes. This can be cut from hardboard or plywood. If strings are used to support the treads the next step is to mark the distance you require between the top edge of the treads and the top of the strings. This distance is known as the margin. Mark it lightly with a marking gauge, or with a pencil and a strip of wood cut to the width of the margin.

Along this line mark off distances that equal the longest side of the triangular template you have cut. Then lay the template along the marked line between the stepped off points, with the longest side against the line. Draw a line on the string along the bottom edge of the template. This will indicate where the top edge of the tread will come. Then mark on the strings the cross-section of the treads. Use a piece of the material you intend to use for the treads as a template.

Mark out this section tight the timber will be cleaned up later and it is desirable that the treads should fit tightly into the strings. If spines are to be used to support the treads, step off the length of the longest side of the triangular template on the top edge of the spines. Do this with the planks laid together and their faces butting. Square lines through these marked points. This will indicate where the top edge of the triangular support blocks should meet the spines. The triangular template can also be used to mark the angle at which the support pieces, either strings or spines, meet the floor.

Lay the template on the pieces at the correct point with the longest side parallel to the top edge of the support piece. The side that indicates the going on the template gives the required angle for the line where the support piece meets the floor. The side that indicates the rise on the template gives the angle for a vertical end to the support pieces, for example for the mortise-and-tenon joint used where a string is inserted into a newel post.

Housing the treads in the strings

The next step, if the treads are to be supported by strings, is to cut the housing joints on the inside face of the strings. The housings should be a minimum of l3mm deep. You can cut them with a power router and a jig, if you have one, and it will save you a lot of time. If you do not have such a tool, you can cut the housings by drilling a series of holes within the areas marked out for the treads. These holes can be cut with an electric drill or a handbrace and bit. In either case it is advisable to use a depth stop to keep all the holes an even depth and avoid the necessity of having to even up the housings later.

A depth stop can be a piece of wood with a hole drilled in it that fits around the bit the required distance from the tip. Stop the wood from moving up the drill with a piece of adhesive tape. Alternatively, a proprietary type of stop that bolts onto the bit can be used.

Drill the holes so that their edges are almost touching. Remove the waste with a chisel and mallet. Carefully shape the front of the tread section to a rounded shape with the chisel; the fronts of the treads should be rounded off to save your shins. The treads can now be cut to length. Each tread should be fitted individually to a particular housing. Number the ends of each tread and each housing so that there is no possibility of mixing up the pieces. The treads and housings can be marked as No. I left, No. I right, No.2left, No.2 right and so on.

Assembly of the staircase

When you have cut the housings and numbered them the strings and treads can now be fitted together as a unit. You may need some assistance to do this, because of the weight of the strings. You will also need two low stools or saw horses and some sash cramps. Lay one string on the stools or saw horses with the face with the housings uppermost. Position the treads in the housings as numbered. Lay the other string on top of the tread ends with the housings downwards. Align the treads with their housings, then apply glue to the upper ends of the treads. Knock the upper string onto the tread ends. Cramp the assembly. When the adhesive has dried, turn the assembly over and knock the other string off the treads. Apply adhesive to the ends and knock the string back down onto the treads. Then cramp the assembly up again. The next step is to screw the treads to the strings.

To achieve a good finish you can either use brass screws and cups or you can use ordinary steel screws counterbored below the surface of the strings. The cylindrical gap between the screw head and the surface of the string can be filled with plugs cut with a plug cutter. These are glued and tapped into the. countersunk holes and arranged so that the grain matches that on the string. Any part of the plugs that protrudes can be cleaned off with a smoothing plane when the glue is dry. Once the assembly is complete, the strings can be cut to the size required. At the top, the strings are fixed to a timber trimmer-a piece of wood slightly heavier than the floor joists, and which will normally be in place already on the upper floor.

The angled end of the top of the strings butts against the side of the trimmer and. is screwed in position. At their bottom end, the strings should be left a little over length for the time being. At the bottom, the strings are fixed to newel posts. There are several methods of fixing these to each other and of fixing the newel post to the floor. In the first, the strings are double mortised into the newel post and a timber dowel pushed through the tenon and the newel post. In the case of a timber floor the newel post can be set into the floorboards so that its bottom end rests on the concrete underlayer of the floor. There should be a damp course between post and concrete.

The second method involves the same joint between the strings and the newel post, but the newel post is fixed to the floor by means of a mild steel dowel. This method is only suitable if the floor is concrete. In the third method, the strings and handrail are housed into the newel post. These are then screwed together. In this construction, the newel post ends at floor level but the strings are inset below the floorboards with their ends butting a floor joist, or a specially inserted timber block between the joists if these run the wrong way.

Supporting treads with spines

This construction method involves supporting the treads from underneath by means of spines. The setting out of the spines was described earlier. The treads, in this type of design, are supported by triangular wooden blocks whose size depends on the going and rise of the treads. Their shape is similar to the triangular template cut earlier. The blocks are housed in a l3mm x l3mm groove cut along the centre of the top edge of the spines. Cut a tongue on the bottom side of each block (the wastage caused by this means that the blocks will have to be cut out slightly larger than your template).

Glue the blocks into the groove so that their top edges are in line with the stepped-off pencil marks made earlier with the template. Screw the treads to the blocks with brass screws and cups, or fix them with timber dowels. The fixing of this design of staircase to the floor and trimmer is the same as that for a staircase constructed with strings, except that the spines are not attached to a newel post.

Walk on floor glass allows natural light to pass through and eliminates the need for artificial lighting during the day. It is a modern material and can also create an open space illusion.The glass can be clear or frosted, with anti slipping properties.
Glass can be used to build a staircase, a floor, roofing, etc.

Glass Staircase & Balustrade

Modern Glass Staircase & Glass Flooring

Clear Glass Floor Lighting source between floors

Glass balustrades Staircase

Glass balustrade and hardwood staircase

External Glass Floor Roof

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Having some knowledge of wood and its properties will help any DIY carpenters, joiners or roofers.

Softwoods are used for general joinery such as joists,rafters, floorboards,joinery, cupboards etc, and is made from a conifer tree (pine, larch, fir or spruce). The wood is usually lighter and softer, easier to work with than hardwood.

Hardwood is made from broad-leaved tree, such as oak, mahogany or teak. The wood is usually denser and harder than softwood.

Manufactured board is made from wood in sheets, strip, shredded or pulped form with resins or glues bonding the pieces or pulp together.

PLYWOOD

Thin layers(‘plys’)of wood are glued together to form aboard which has neither the warping nor splitting tendency of natural wood. This property is due to each layer being laid at right angles to its partner and an odd number of layers being used to make up the finished board. The number of plys varies from 3to 15 – the board thickness ranges from la-1 in. There are many grades: INT for indoor use, WBP (weather- and boil-proof) or EXT for outdoors, aviation for beading, hardwood veneered for high-quality appearance, structural for maximum strength and plank-faced for panelling.

BLOCKBOARD
The inner core consists of strips of softwood glued together. The annual rings of the strips are at right angles to each other and this core is sandwiched between two thin layers of wood – usually birch. ln top-quality blockboard these sheets are faced with decorative hardwood veneers. Board thickness is %-‘l in. and is worked in the same way as ordinary timber. A few words of caution: do not nail or screw too close to the end of the core strips and never paint just one face – treat both faces in the same way. Do not use blockboard outdoors. Laminboard is a version of blockboard in which narrower strips of wood are used for the core.

CHIPBOARD
Small chips of softwood are bound together with a resin adhesive and the sheet is squeezed between rollers to the required thickness. It is cheaper than plywood and blockboardand is widely used as a base for furniture because of its even texture and resistance to warping. For maximum strength buy the multi-layer grade, for painting buy painting quality which has densely-packed small fibres on the face and for underfloor look for the flooring grade. A multitude of faced varieties are available for making furniture and worktops. There are problems. It will bow if the support is inadequate, the cut edge may be ragged, special screws or inserts must be used for fixing and it is not suitable for use outdoors.

MDF

(Medium Density Fibreboard) The base material for fibreboard is made from the fibres produced when timber is subjected to a vacuum in a pressure chamber. These fibres are bonded with resin and then rolled -the pressure used has a profound effect on the quality of the fibreboard. Low pressures produce pinboard which is used for notice boards – high pressure produces panel board for wall lining. Medium density fibreboard is an exciting modern material which although very widely employed in the furniture industry is not often used by the home handyman. Rather similar to chipboard, but with the great advantage that it can be cut cleanly, nailed or screwed without problems and has a surface which can be stained, polished or painted.

HARDBOARD
Pulped wood is mixed with adhesives and rolled into sheets. This Cinderella of the manufactured boards is cheap and has little inherent strength, but has many uses around the home. Standard grade (smooth front face, roughened-mesh backface) is bought for covering doors, floors, drawer bottoms etc. There are perforated boards pierced with round holes (pegboard) or decorative shapes, and there is the tempered grade which has been impregnated with oil to make it water resistant. Enamel- and plastic-tinished boards are used where a decorative effect such as a tile or wood-panelling look is required.

SOFTWOODS

CEDAR WESTERN RED
Reddish-brown with a silky surface. Resists both rot and insects and so is popular outdoors for cladding, fences and
sheds. lt has its problems – colour fades with time, nails work loose and the surface is easily dented.

FIR DOUGLAS
Popular with furniture makers and house builders – very strong and quite cheap, and also knot-free. Sometimes sold
as British Columbian pine – pinkish-brown and even textured but paints badly and cracks outdoors.

HEMLOCK
A general-purpose softwood from Canada and the U.S., used for doors, floors, joists etc. Strong and easily worked
but not good for painting or outdoor use.

LARCH
A British wood, tough and difficult to work. There are 2 important characteristics – it has good rot resistance and
holds nails well. As a result it is used for construction work indoors and fences etc outdoors.

PINE, PARANA
A fine-textured wood, attractively coloured in cream, brown or lilac and otten knot-free. Very strong (used for
staircases) but also temperamental – warps easily, splits outdoors and provides a poor surface for painting.

PINE, PITCH
A wood steeped in history – great halls, church roofs and barn walls are a testimony to its durability. Rich in resin,
highly inflammable, rather difficult to work and even more difficult to find.

REDWOOD
The most popular of all woods for the home carpenter – inexpensive, reliable, easy to work, good for painting, etc.
Colours range from cream to reddish-brown, commercial names include Scots pine, Baltic pine, red deal and ‘pine’ furniture.

WHITEWOOD
Popular and inexpensive like redwood, but there are differences. It is softer with a finer texture, and the cream colour does not darken with age. Whitewood (other names – spruce, white deal) does not absorb preservatives not for use outdoors.

YEW. The softwood that thinks it is a hardwood. Yew is very heavy and close-grained – the colour is orange or brown.
It is a wood used by cabinet makers and craftsmen to produce high quality articles.

HARDWOODS

AFRORMOSIA
A wood from tropical Africa. Close-grained and golden-brown like teak – used as a less expensive substitute in furniture manufacture. Available for the home carpenter in both solid and veneer form.

ASH
A pale-coloured timber with many uses – panelling, flooring etc. The 2 traditional applications are bentwood chairs
and tool handles. The expert carpenters will tell you to avoid boards with brown streaks.

BEECH
A European wood which is often used in the furniture industry for making a stout and durable frame for veneering. The colour is ivory to pale brown and the grain is straight. Not recommended for outdoor use.

CHERRY
A wood with a wavy grain and a distinctive orange sheen – more often seen as a veneer than as solid wood.
A material tor the cabinet maker and craftsman; but American cherry is sometimes used for joinery work.

CHESTNUT,SWEET
Similar to ash but less expensive – used as a substitute for making office furniture. It is also used as a substitute for oak, which it quite closely resembles. No real drawbacks, but dark streaks can be disfiguring.

ELM
Coffins, wheelbarrows and Windsor chairs are traditionally made from this brownish rough-grained timber. European elm is very durable, but now scarce because of the ravages of Dutch elm disease. Japanese elm is less robust.

IROKO
A popular teak substitute – hard-wearing for both indoor and outdoor use at a significantly lower price. You will find its rich brown colour in parquet floors, furniture, garden seats etc. The texture is rather coarse.

JELUTONG
A wood to buy if you wish to try your hand at carving. Very pale, soft, straight-grained and even-textured.
It is also useful for home carpentry – the surface is smooth and it is easily worked.

LIME
Like Jelutong, an excellent wood for carving and turning. The texture is fine and the grain is straight – the yellowish-brown colour has practically no figuring. Not a popular wood – you may have to search to find it.

MAHOGANY
One of the great.woods, now more often used as a veneer than as solid timber. Not all mahoganies are the same. The African type has a rich orange-brown colour and a distinctive figuring – American is more even in appearance, more
expensive and more lustrous.

MERANTI
A mahogany substitute from Malaysia – cheaper, redder and easier to work than real mahogany. It is quite widely
available in sheet and veneer form and as mouldings – so is the closely-related lauan from the Philippines.

OAK
It is not just patriotism – British oak is the strongest, straightest and most durable of all oaks. Its toughness is
legendary, but it is expensive, difficult to work and glue, and splits easily when nailed. European oak is a little softer.Japanese is even lighter and not suitable for outdoors.

OBECHE
Not a quality hardwood – it is a light, easily-worked timber used in the manufacture of whitewood furniture. The grain is open and the colour pale – obeche can be stained and polished.

RAMIN
A very popular hardwood which you will certainly f ind around the house in mouldings, picture frames, furniture etc.
It is a straw-coloured wood, close-textured and easy to nail. A favourite material for the home carpenter.

ROSEWOOD
An expensive wood for the luxury look. The rosewood furniture you see is almost certainly veneered over a cheaper carcasses. Purples and browns swirl under the high lustre finish – you can buy boards as well as veneer but you will find it a difficult wood to work.

SAPELE
A mahogany look-alike – strength and colour are similar but it is less expensive. One drawback – it has a tendency to warp. Sapele is usually bought as a veneer – it polishes well but staining can produce a patchy finish.

TEAK
Teak is widely used in furniture manufacture these days both in solid form and veneer, its rich brown colour marbled
with darker streaks. Apart from its visual appeal it resists rot, water and fire – teak is therefore used for outdoor
furniture, ships’ decks etc.

UTILE
Like sapele,one of the mahogany look-a likes. It has a pink-brown colour and an irregular grain – this wood is easily
worked and is less inclined than sapele to warp. Widely used in the furniture industry.

WALNUT
Best of all is European (especially English)walnut – mid brown with dark streaks and swirling patterns beneath a
lustrous finish. Long associated with antique furniture – today’s walnut table will only be veneered on a cheaper
frame. African walnut is easier to obtain but is less attractive.

Tool box and tool carriers for tradesmen – organize your tools with these practical carriers and tool box. They are all quite simple to make, and for the carriers you can use offcuts and scraps of wood.

Keeping your tools tidy helps to keep them in good condition and if they are all ready to hand it helps you to work more efficiently too. There is ample room in this tool box for a comprehensive kit of woodworking tools, each in its own place. The two tool carriers are ideal for jobs which you have to do outside the workshop—at locations where you need just a few selected tools and materials.

All three are quite simple to make, although the tool box has a more complicated dovetailed frame. All of them use the minimum of materials, and you can probably make the carriers from offcuts and scrap. Both the tool carriers are made in a similar way. The main difference is in the dimensions and the divisions fitted in the smaller one. The larger tool box also has strengthening blocks fitted to the corners. The joints are simple glued butts, reinforced with carefully inserted pins.

Cut out all the parts from plywood. There is no reason why you cannot alter the dimensions slightly to suit pieces of wood which are available, or to suit the size of particular tools. Glue and pin the box together and fit the dowel handle in place. There is no real need to finish the wood at all, but it is a good way to use up scraps of paint or lacquer left over from other jobs.

It is a good idea to leave the centre of the handle unpainted as it gives a better grip: The tool box is a basically simple construction, but it is complicated by the dovetailed corners. Although these give a much stronger frame, if you prefer you can replace them with box joints or even butts, reinforced with corner blocks. Make the rectangular frame first, taking care to keep the corners square. If you are using dovetails, note that one of the upper joints is wider than the rest. This is to allow for the saw cut which separates the lid . Make this when the frame is dry.

Fit the plywood front and back panels, which are glued and pinned in place. Glue and pin the hinge fillets along the edges of the lid and fit the piano hinge. Make up the two drawers and fit their runners. You can add divisions as you require. Fit the bracket for the hand brace. If you wish, you can make a similar bracket for a coping saw. Fit turnbuttons inside the lid, positioning them to suit your saws. Finish all the timber with lacquer, then add clips and a handle.

• Different types of door
• Internal and external door frame construction
• Common door problems
• Removing and straightening warped doors
• Altering a door frame
• Repairing and replacing damaged door frames

Warped or damaged doors need not necessarily be scrapped: very often you can save money by carrying out your own repairs to the door itself, or by modifying the frame or door stops to accommodate the damage

Doors and door frames are as susceptible to damage as any other part of the woodwork in your house. And although you can buy new doors and frames ‘off the peg’ to replace rotten or damaged ones, you can save yourself a great deal of money by carrying out simpler repairs and maintenance before it is too late. We describe some of the steps you can take to rectify simple door problems,dealing with the specific problems found on traditional, side-hinged garage doors. Re-read these pages before you start work.

Types of door

There are three basic types of door: the ledged and boarded door; the panelled door; and the flush panelled door. Standard sizes of most types are available, but remember that interior doors are usually narrower and thinner than exterior doors. Softwood is the most common construction material, although hardwood, metal and plastic are also used. Ledged and boarded doors: These are made from vertical tongued and grooved boards, nailed to horizontal ledges and diagonally braced.

The simplest doorframe of all—a doorway in a stud partition wall. Removal and replacement of this kind of door frame is comparatively easy.
The diagonal members resist the tendency to sag, and a stronger version has vertical stiles on the shutting edges to which the ledges are attached. Most locks can be fitted to this type of door, although the diagonal braces must be retained to resist sagging and warping.

Panelled doors: These have a solid frame made up from vertical stiles and horizontal rails which enclose the panels. The panels can be made from plywood or glass, and are usually fixed by mouldings running around the inside of the frames. One side of the panel fits into a rebate and butts against the moulded edges of the stile and rail; a matching bead is pinned and glued to the other side of the panel to hold it in place. Panelled doors are available in a variety of sizes, and you can plane the edges to suit the size and shape of your opening.

Flush panelled doors: These usually consist of an internal wooden frame to which a plywood or hardboard facing is pinned. Between the two facings you will often find insulating or fire-resistant material—although some exterior doors are solid. Because the facing panels help to prevent the door sagging, the stiles and rails are often very narrow. When you buy a new door, therefore, make sure that it is as near the same size as the frame as possible or you may run out of timber to plane off the edges. Some flush panelled doors have a plasticized coat on the facing for use in bathrooms and if you must plane a door like this, protect the coat by lining the edges with masking tape. Afterwards you can protect the bare timber with polyurethane lacquer.

Doorways and linings
Doors need doorways as most carpenters knows, and it is very often the door frame rather than the door which requires your attention. Again there are three basic types, each one intended for a different type of wall construction. The simplest type of frame construction— used in stud partition walls—consists of lining boards at the top and on each side of the opening.

These can be bolted, screwed, or nailed to the wall studs. A similar construction is used for doorways in brick partition walls, though in this case the lining is often attached to a timber ground which is fixed directly to the brickwork. The ground and/or lining may be fixed to the wall with screws and plugs, with fixing cramps, or with screws driven into wooden blocks set into the brickwork itself. If you need to, you can find out exactly how the frame is fixed by prising off one of the vertical architraves, chipping away the plaster, and looking in the gap between the lining and the surrounding masonry. Either of the above types of construction can use rebated or planted stops and both are surrounded by wooden architraves. The architrave is simply a timber moulding which is nailed over the joint between the wall plaster and the doorway lining to conceal the gap. It is usually pinned to the lining with a mitred joint at the top corners, and can easily be prised away undamaged.

Should you need to do this, knock out the old nails and refix it with new nailing, then fill the old nail holes with putty before repainting. Exterior doorways are slightly different. Here a hardwood sill is usually an integral part of the frame, which is itself fitted directly into the opening and is secured to the surrounding masonry by galvanized steel fixing cramps.

The cramps and door frame are fixed into the wall as the brickwork is erected. Sometimes the horns of the frame-ends which project horizontally from the top of the main frame are also built into the wall. Exterior door frames are much more likely to suffer from wet rot than interior ones, so on most door frames the gap between the frame and the wall is sealed with non-hardening mastic to prevent moisture getting in and attacking the frame from behind. For the same reason, the gap should also contain a vertical damp-proof course of PVC or bituminous felt.

Sticking doors
Sticking doors can be caused by sagging joints in the door itself, by sticking hinges, or by a damaged door frame. Planing the edges of the door or resetting the hinges may cure minor problems, but to repair bad cases you will have to completely dismantle and refurbish the door and its joints, and/or the door frame. An interior doorway in a brick partition wall—structurally stronger than a stud partition door frame but more trouble to replace interior door in partition wall.

Twisted or warped doors
Panelled and ledged and boarded doors are prone to twisting and warping. When this happens, the door does not close properly and the lock and latch often mismatch. Unfortunately, in the case of ledged and boarded doors there is not much you can do to rectify this other than complete refurbishment or replacement. You could try replacing the most badly twisted boards, or screw a couple of sturdy ledges to the exterior face of the door, but this is not always successful. Panelled doors are as difficult to rectify, but your chances of success are higher. However, if the door is glazed, remove the glass before trying to carry out any work. The first solution to try is forcing the door against its twist.

Close the door until it just touches the doorstop, then measure the gap where the door does not touch. Cut and shape a wooden block slightly larger than this gap and fit it between the door and the stop at the point where they first touch. Force the door shut along its length, wedging it firmly in place for two or three days while the house is empty during the day and at-night. A method that is more likely to succeed involves a good deal more work. Remove the door and place it on a bench with the side towards which the stile twists facing upwards. Remove the nailed beading on this side and with a tenon saw make a number of saw cuts across the stile in the area where the curve is greatest, cutting halfway through it . Cramp the door to the bench to pull it flat. Next mark cutting lines for notches 25-40mm wide either side of the saw.

Follow by marking the depths of the notches—which should be no more than a third the thickness of the stile—on the edges of the stile. Use a sliding bevel to make the edges of the cut-out slightly undercut like a dovetailed joint. Then remove the waste with a tenon saw and a bevel edged chisel. Cut softwood wedges to fit each cut-out, making them slightly longer than the width of the stile and with the grain running in the same direction. Tap the wedges into the cut-outs and release the cramps to see if the door remains flat—it may be necessary to recramp the door and tap the wedges further in if it remains curved. When the door is flat, cramp it up again, mark the wedges for length, remove them and cut them to the correct size.

Glue them up and replace them, allowing the adhesive to dry before removing the cramps for the last time. You can then plane the wedges flush, fill the saw cuts with wood putty and repaint the door. If possible, change the hanging side of the door so that the hinges keep the repaired stile true. Altering the doorstop The easiest solution to the problem of a twisted door is to alter the doorstop, though this sometimes has the disadvantage of being unsightly. Planted doorstops are removed simply by prising them away from the frame with a bolster or screwdriver. But first run the point of a knife down the inner corners of the stop on both sides to prevent unnecessary damage being done to the paintwork.

Remove only those stops on the lock side and along the top of the door; leave the stop on the hinging side where it is. Push the door to its closing position, filing the lock’s striking plate if necessary. Remove the old nails from the stop, then re-nail the stops so that they bed as consistently as possible against the door. Fill the old nail holes before repainting the stops. In bad cases, the stop will form an unsightly margin with the architrave and you may have to plane it slightly to follow the contour. If the doorstop is rebated, you will have to cut the stop to the new alignment. Remove the striking plate, close the door until it touches the stop, then measure the gap at its widest point. Plane a small block of wood to this size to use as a gauge.

Place the block against the edge of the door where it touches the stop and, with a pencil on one side of the block, run it up the length of the door marking a line on the doorstop. This will show how much wood you have to remove to accommodate the warp. Score down the line with a metal straightedge and a sharp knife to prevent the paint from tearing back. Repeat the operation on the inside edges of the stop. Then, starting at the narrowest end, cut in towards the lining with a firmer chisel and a mallet. Alternate your downward cuts with cuts into the inner corner of the the lining.

When all the wood is removed, use a rebate plane to tidy up the inside edges. Finally, replace the striking plate in a different location and chisel out a new rebate to engage with the lock on the door. Frame repairs The most common form of damage to door frames is wet rot, which may make the timber swell and consequently cause the door to stick or parts of the frame to pull away from their wall mountings. Depending on the extent of the damage, you may be able to remove the rotted section and patch it with new timber. If so, you should use a lapped joint and secure the new section to the wall with masonry bolts as described.

For a professional finish, lay a strip of polyethylene or PVC between the repair and the masonry, and reseal all the joints at the wall with a non-hardening mastic. This prevents the wet from attacking timber from behind, where it is unprotected by the paint on its outer faces. Bear in mind that although paint protects the timber beneath it, urban grime attacks the paint and gradually reduces its effectiveness to the point where rot can gain a foothold.

Regular cleaning therefore helps to protect the timber from rot and also enables you to identify problem areas before it is too late. You will quite probably see the first signs of rot as bubbling on the paint’s surface. If the rot is too extensive to be patched, you will have to instal a new frame. Fortunately, this is a less daunting prospect than it seems. Your first step is to measure the dimensions of your opening and the size of your D. One method of curing warps in a panelled door. The saw cuts should go no deeper than the level of the panels, and the wedges should stick out at both ends when hammered in door—assuming that you do not wish to alter the dimensions—and to either purchase a frame of the appropriate size and dimensions, or to make one yourself (a technique covered further on in the Carpentry course).

Many larger timber or builders‘ merchants supply door sets consisting of a door and door frame with all surfaces sealed and primed, a lock, lift-off hinges, and full fitting instructions. These save time and a good deal of work. But if you need only to replace the frame, measure up the old one—particularly its overall width and height—and purchase a new one compatible with your existing door. If you want to refit the old door, the inside jamb measurement will need to be the width of the door or less; it will be no good if the door is too small for the frame, though you can plane down a door that is too big.

Remove the door and place it on its side out of the way. If the door frame is butted against the floor and not built into a wooden threshold, prise it loose carefully with a crow-bar working from the bottom upwards. If the horns of the top rail are built into the wall, use an old saw to cut through the rail then prise it off, wriggling both ends free from their mountings. Where the frame has a built-in hardwood threshold, do the same here so that you can prise the jambs free from the wall. When the frame is out, brush down the walls and examine them. Sometimes frames are fitted to brick walls by screwing to wooden blocks built in to the brickwork and if this is the case you may be able to use the existing blocks. But remove them if they are loose or rotten and insert new ones, making sure that they are firmly packed and mortared into the brickwork.

With a heavy pencil or chalk, mark the positions of the blocks on the wall to one side of where the frame will stand. This will make it easier to locate and screw into them. Next, put the frame in position and use a level or plumbline to establish the vertical. Lightly mark the frame opposite the blocks in the wall as a guide for drilling the screw holes. Then remove it and drill countersunk holes which you can fill later. Place the frame back in position, level it and check its diagonal dimensions to make sure that it is true; then fix it to the wooden blocks using No. 8 woodscrews 75-100mm long.

You may need to pack small battens between the frame and the wall to take up any unevenness, so bear this in mind and keep checking the squareness of the frame as you screw into the bricks or studs. If the old frame is fixed with galvanized steel cramps, you will be unable to re-use the old cramps. So, when you place the frame in its experimental position, mark on it suitable positions for fixing screws drilled directly into the masonry.

You will have to drill into firm brickwork— not the mortar joints—so mark the positions accordingly. Then remove the frame and drill at least three holes on each jamb to take No. 8 or 10 countersunk wood-screws 65-100mm long. Afterwards, replace the frame, level it, and check its diagonal dimensions to ensure it is square. Wedge the frame temporarily in its true position, and mark through the drill holes into the brickwork with a long masonry nail. Then, before you remove the frame, mark its position clearly on the wall so that you can match the holes later.

With this done, remove it and drill the holes in the brickwork with a masonry bit of the correct size. Insert wall plugs to match the screw size you are using and replace the frame aligned with the marks just made. Finally, to finish off the project, fill all the holes in the frame with a proprietary wood filler and then point around the door frame with a 1:3 mortar mix. When the mortar has set apply a liberal amount of nonhardening mastic to all the joints.

You can have an attractive cabinet as a useful piece of bedside furniture. The simple design is easy to build, and you can adapt it in many ways to suit your own requirements.

This practical bedside cabinet is a simple box construction in veneered chipboard. You can build it with three drawers for maximum storage, or omit one or more drawers and fit shelves or a cupboard door.

Whichever way you want to build it , the main carcase is the same. If you are fitting a shelf, do so when you assemble the carcase. All the drawers are made in the same way, by grooving and housing the chipboard sides. Finish all the cut edges with iron-on edging strip to match the veneer, and sand down thoroughly. Finish with lacquer or paint as you require, then fit the handles or drawer pulls of your choice to suit the finish.

Roofing with PVC sheet

• The applications of corrugated PVC sheets
• Types and sizes
• Buying PVC sheet
• Hints on working with PVC sheet
• Weatherproofing
• Sealing with adhesive flashing
• How to fix the sheeting to the roof framework

Transparent or translucent PVC sheets, corrugated to add strength and rigidity, can be used both for roofing and for cladding walls. The material is lightweight, so it is easy to handle. And it is simple to cut, making it ideal for DIY work. Among the applications to which it is admirably suited are carports, sheds, lean-tos and conservatories. If you need roofers in London, contact us.

And, although this feature concentrates on using PVC sheeting for roofing, most of the details apply to wall cladding as well. Types and sizes The most popular type of sheeting— ’75mm round profile’ has smoothly rounded corrugations with a distance from one ‘peak’ to another of just under 75mm. Sheeting with squaredoff corrugations is also available and again, the distance from the start of one corrugation to the start of the next is about 75mm: this is known as ’75mm box profile’. Some sheets have smaller, rounded corrugations and are known variously as ‘mini profile’, 38mm, or 32mm profile.

These are best suited for wall cladding, or for short roofing spans such as those found on lean-tos. A larger, heavy duty sheet is available for particularly big roofing jobs. The 75mm profile type usually comes in 760mm wide sheets, measured across the corrugations. Lengths vary from around 1.5m to 3m. Modern transparent sheeting is very clear and lets through most of the available light, but you can also buy translucent clear and coloured sheets including a semi-transparent white.

Buying PVC sheet

Some brands of sheeting, although clear when they start life, become opaque over the years with the action of sun and rain. If it is particularly important that the sheet remains clear for example, if you want to use it in a conservatory or greenhouse, make sure you pick a brand that guarantees clarity. Even clear sheeting varies in its ability to let through light so again, if you are planning a greenhouse, pick a brand that lets through the maximum amount.

When you are selecting sheets, check that they are not split, damaged, discoloured, or distorted. When you get them home, stack them flat—on battens and covered with a tarpaulin, if they are left outside. Although you should never stack it in direct sunlight, cold weather makes PVC brittle and it is a good idea to leave the sheets in a warm room for a day before cutting.

When you are calculating quantities assume each sheet covers about 10 percent less than its actual area to allow for the overlap at the sides with adjoining sheets. At the same time, buy a supply of purpose-made fixing screws, allowing roughly 25 for each square metre of roof area. Round-head chrome plated screws, 45mm long, are the best for roofing work. Special plastic caps and washers are needed to waterproof the holes through which they go, so it is sensible to buy a supply of the fixing accessory packs that are sold for use with the sheeting; indeed, if you do not, you may lose the benefit of any guarantee you get.

The structure which supports the sheet is normally timber and often ends up more complicated and costly than the covering itself. Choose only well-seasoned timber and make sure that it is adequately preserved before you fit it. Bear in mind that you may need flashing materials to seal a joint between the sheet and an existing wall. Working with PVC sheet PVC sheeting is quite easy to cut and drill, providing you follow some simple rules.

It can be marked for both with a felt-tip pen and obtrusive marks may be removed by rubbing with a cloth soaked in methylated spirit. One handy hint which aids marking out is to cut a strip of the material and use this as a template for all further cutting. Cutting is best done with a tenon saw or fine-toothed panel saw, though for cutting off small pieces you could try tinsnips or a pair of heavy scissors.

Cut at a shallow angle, and support the sheet carefully on both sides of the line down which you are cutting . In cold weather it is best to cut indoors—and handle the sheeting especially carefully. Holes for the fixing screws should be drilled slightly larger than the diameter of the screw shank to allow the sheet to expand freely. With the type of screws usually used for roofing, a 7mm hole—giving a clearance of about 3mm—is ideal.

Support the sheet on the opposite side to which you are drilling the hole and do not allow it to bow under pressure. Both hand and power operated drills can be used, together with ordinary twist bits, but you may find that a slightly blunt bit makes a cleaner hole than a new one. Make larger diameter holes by drilling a circle of tiny holes—say 3mm diameter and then joining these up with a fine padsaw blade. In this case increase the clearance for expansion to around 4-5mm.

The corrugations on PVC sheet give it some degree of rigidity, but it still needs to be well supported if it is not to fly off in the first high wind. The main supports are purlins—the timbers which run at right-angles to the direction of the corrugations in the sheet. These should be set no more than 600mm apart—so a sheet 1.8m long must be supported top and bottom and by two inbetween. The purlins, which generally measure 25mm or 38mm in width, are in turn supported by rafters running at right-angles to them along the direction of the corrugates.

The distance between the rafters depends on the depth of the purlins.If your roof is small and you use thick purlins – you don’t need rafters, the purlins can be supported on whatever forms the ends of the roof structure.

Weatherproofing The easiest way of ensuring that a simple structure is reasonably weathertight is to allow the sheets to overhang it all the way round. The amount of overhang at the bottom of the slope depends on whether you want guttering: if you do, arrange the overhang so that rainwater will flow properly in to the gutter; i f not, have a larger overhang so that the rain is thrown clear of the base. An overhang of 250mm would not be too large. For a more airtight structure, the top and bottom can be filled with eaves filler strip, foam strip in the shape of the corrugations. The strips should be placed on the supporting timbers before the sheets are fixed in place and the fixing screws driven through them. Hold the strip in place as you insert the screws.

Overhanging sheet looks unattractive if left by itself so for a neater appearance, fix fascia boards all round—whether you are fitting guttering or not. The fascias are best fixed directly to the purlins or rafters, so arrange for these to overhang the structure by a suitable amount. Whatever the size of your roof design, you should make sure there is a slight fall towards the gutter edge and along the corrugations, not across them.

A fall of 10° or more is preferable although much steeper slopes can be used if you want. Try to co-ordinate your design and the sheet sizes so that you do not have to join sheets end to end. Alternatively, redesign the structure to suit—for example by turning the slope through 90°, or siting the gutter in the middle of the span, rather than along one edge. If you do have to join sheets end to end, they must be overlapped by at least 150mm with a purlin below.

Flashing

There are two main methods of sealing the joint between the sheet and a house wall. The easiest is to use proprietary, flexible, self-adhesive flashing strip in conjunction with its own bituminous surface primer. This is easy to apply, and is pliable enough to fold into the corrugations. An alternative method where the corrugations are to run at right-angles to the wall. Here, you lay the sheets half way up the final purlin—which should be wider than the rest—then fill out the rest of it with strips of packing timber, the height of the corrugations.

You then lay a final timber strip the same width as the purlin over the sheet ends and the packing. Push this up against the house wall and secure it by nailing through the packing to the purlin. Seal the gap between the wall and the strip by packing i t with a suitable mastic. The same technique can be used to form a pitched roof ridge’. Where the corrugations run parallel to the house wall, a wall plate carries the ends of purlins rather than rafters, and the fixing and sealing arrangements are a little different.

Round profile sheet can be sealed to the wall plate with bevelled timber packing pieces—one above the sheet, and the other below. Bed in the edge of the sheet with mastic. The technique can be used with box profile sheet too, but a neater method is to cut a groove in the wall plate with a circular saw, and to ‘spring’ the edge of the sheet into this. Remember to cut the groove at the same angle as the roof slope and again, bed in the sheet ends with mastic.

Double glazing

Heat loss through PVC sheet is very high, and this makes i t unsuitable for use as a permanent room. However, some of the heat loss can be reduced by ‘double glazing’—fixing another layer of sheeting to the underside of the supporting purlins. In this case, weatherproofing is unnecessary and you can fix the sheet in its valleys, using shorter screws.

However, it is important to seal both exterior and interior layers, so that the air in the cavity is still. Use eaves filler strip at the edges, and overlap joints in the same way as for the exterior layer. If there are rafters in the construction, cut the sheet to fit between them and seal the joints between the two. It is essential that both interior and exterior layers are of the clearest sheet you can get—less transparent sheets may lead to a build up of heat in the cavity, causing them to warp.

Fixing the sheet

When you come to fix the sheets to the supporting structure, you may find yourself doing more than one job at once. For example, it would be better to fit self-adhesive flashing as you go along rather than leave it to the end and risk falling through the roof. And, if you are sealing joints, have the necessary materials to hand before you start overlapping. On a roof, the idea is to have the joint overlaps running away from any prevailing winds, with the slope.

You must bear this in mind when you choose which end to start sheeting; and if sheets are to be joined end to end, fix the bottom row first. Lay the first sheet at right-angles to the supporting purlins, at one end of the structure. Drill screw holes through the first corrugation on the non-jointed side to both end rafters and all purlins; on a standard, 1.8m long sheet this should mean at least four fixings. Note that the holes should run through the crest of the corrugation. You may find that there is not enough support beneath a crest for you to drill without distorting the sheet.

In this case, mark the positions of all the fixing holes and turn the sheet over, you will find that the crests have become valleys, and are easy to drill through. After drilling turn the sheet back again and fix through the first corrugation, taking care not to overtighten. Continue in this way along the sheet, drilling and screwing at every third corrugation, but do not yet fasten the last corrugation.

Now lay the next sheet on the structure, lap its first corrugation over the last corrugation of the preceeding sheet, and fasten the two together. Repeat the process for subsequent sheets, if necessary completing any sealing and fastening work as you go. If there is to be an upper layer of sheeting, it must overlap the other by at least 150mm and by twice as much if the roof slope is less than 10°. You must remove the topmost row of fixings on the lower sheets before fixing the upper ones in place.

Replacing single glazing pane windows to double glazing is a cheaper way to insulate your home, especially if you don’t like having PVCu windows and doors.

Plastic frames windows and doors,even thought they are virtually maintenance free, are considered to be in bad taste, and many people would rather have wooden framed windows and doors. Replacing the windows and doors with new – double glazed units, can be very expensive, around £2000 per (normal sized) window. If you have sash windows, the cost is even higher.

Single glazing can be replaced with double glazing if the frame and the structure of the windows and doors allows for a thicker glazing unit to be fitted. Sometimes the doors can’t accommodate the double glazing thickness for security reasons, and if the window has a large pane – the structure/frame needs to be reinforced in order to support the weight of the new double glazed unit, which is double of the original glazing.

In most cases, the glazing putty that older windows have around the window panes needs to be replaced, and the best way to remove hard putty is by heating it up using a blowtorch or a heat gun. Removing the paint and beading in this way will damage the paint work, but in most cases, the windows and doors needs to be repainted in the first place.

Double glazing or triple glazing units/panes are made from glass window panes separated by air or gas filled space (sealed unit) to insulate the building from losing heat. It also soundproofs the windows and doors.

The efficiency of the double glazing is measured in U – value and the most popular sizes are the 12mm, 16mm or 20mm air or gas gap , with 4 mm glazing x 2.

Contact our London carpenters for a free quote.