Roofers and Carpenters in London

Roofers and Carpenters in London

Reupholstering an armchair

Reupholstering a padded armchair may seem a daunting task; but as long as you are familiar with the basic reupholstery techniques described and are prepared to take time and effort over the job, you should be able to tackle it successfully. Here we explain how to strip an armchair to its frame and replace each part of the upholstery. It may not be necessary, however, for you to strip the chair completely; if, for example, only the stuffing needs replacing, you can leave the layers underneath intact. Before you begin any work on the chair, it is important to make copious notes and clear diagrams of how and where each part of the final cover is fixed. Very few chairs are upholstered in exactly the same way and you may find some of our instructions will not apply to your particular chair; your notes and diagrams will ensure you replace everything correctly and retain the shape of the chair.

Stripping the chair
If the frame needs attention, you will have to strip the chair right down. Turn it upside down and place it on trestles or a firm table. Using a mallet and an upholsterer’s ripping chisel, remove the tacks which secure the bottom canvas. Turn the chair right side up and remove the outside back and outside arm covers; on some chairs these will be secured with tacks, but on others they will be slip stitched invisibly. Again, make notes and diagrams to ensure you can replace the covers correctly. Continue by stripping the seat; remove all tacks, including those holding the webbing, from the bottom frame of the chair and lift out the seat intact. Cut the twine holding the springs to the webbing and hessian, count the springs and note their size so you can replace them if necessary. Remove the seat cover and hessian from the stuffing by cutting the stitches; but leave the scrim in place so you do not disturb the shape. Remove the inside back and inside arm covers which are tacked to the outside of the back and arm frames. Also detach the scrolls, if any; these will be stitched on. If the chair has a calico inner cover, this will be tacked on and should be removed. Take out the tacks securing the scrim which holds the stuffing in place and lift off both the scrim and the stuffing without disturbing the shape. Finally remove the hessian.

Repairing the frame
Check the condition of the frame; you may have to get a carpenter to repair any loose joints and replaced damaged sections of timber. Check the frame has not been attacked by woodworm; treat with woodworm fluid if necessary and allow it to dry before continuing, otherwise the furnishing fabric may be spoiled. Fill any holes left by the original tacks with filler or plastic wood and rub smooth with abrasive paper.

Replacing the webbing
Turn the chair upside down and, using a web stretcher, hammer and l6mm improved (heavy) tacks, flt new webbing over the base of the chair seat in the same way as the original webbing. Turn the chair right side up and stretch two pieces of webbing vertically on the inside of each arm frame. On the inside back fix three vertical strips of webbing and weave two horizontal ones through them to support the back stuffing.

Replacing springs
Place the seat springs on the webbing in the same position as they were originally fixed. Keep the front ones well forward to take the strain of the front edge; the other springs should be placed slightly towards the centre of the seat to allow clearance at the arms and back for the stuffing. Working from the inside of the seat and using twine and a springing needle, secure the base of each spring to the webbing; make three over sewing stitches in three places, with a long stitch underneath connecting each set of three. Lash the springs with lay cord or sisal.

Inside back
If the chair has back springs, these should be placed at the junctions of the webbing and secured with oversewing stitches in the same way as the seat springs. There is no need to lash these back springs.

Battersea flat roofing

Our roofers have started to use Fibreglass roofing instead of the traditional bitumen felt roofing and asphalt roofing.
Using a brand called Cure It Flat Roofing System, the roofing jobs take less time to complete.
fibreglass flat roof membrane
This particular flat roof is actually a converted loft in Battersea, Central London.
flat roof fibreglass system

Repadding a drop seat dining chair

A dining chair is subjected to a lair amount of wear and will eventually become flattened and need a new cover. Repadding and recovering this type of chair is a relatively straightforward job. It is likely the wood frame will have lost all its natural oils through years spent in a heated home and will be liable to split unless handled with care. When you are stripping off the old cover, carefully push an old wide-bladed screwdriver or an upholsterer’s ripping chisel under each tack and ease it out with the aid of a mallet; make sure you work with the grain of the wood to avoid knocking out tiny pieces or splitting the frame. When you have removed all the tacks, clean up the frame with medium fine glasspaper and check for cracks and woodworm. Treat woodworm with a proprietary brand of woodworm killer and fill any cracks with plastic wood. If the chair has been reupholstered a number of times, there may be a lot of tack holes; it is best to fill the larger ones with plastic wood to give the frame extra strength.

Repadding the seat
A sagging seat usually results from damaged webbing or a broken plywood base; or the padding may have flattened through wear. Loose webbing should be replaced and covered with hessian as described earlier in the book. Traditional hair and left padding can be put back into shape if the hair has not become too knotted. Remove the felt layer first, then break up any large lumps of hair with your hands, distributing them evenly, and wash them in warm water. You may need more hair to build up the padding if it is old; this is fairly difficult to obtain and it may be easier to replace this type of padding with polyester foam.

Foam padding
Use a medium-to-high density foam for replacing old stuffing; a type which is 25mm thick would be most suitable. Carefully measure the frame seat and, using a sharp knife, cut a piece of foam which is slightly larger all round to ensure a good fit. Most dining chairs look better for a slightly raised effect and you can achieve this by sticking a piece of 13mm thick foam, about 75mm smaller all round, on the underside of the main piece in the centre. Attach the foam directly to the frame by gluing

Rewebbing a chair

A sagging or lumpy chair seat indicates the springs or the webbing have come away or the webbing has simply worn out; it also indicates the seat padding is in poor condition and needs replacing. Re-webbing a chair is a fairly straightforward job, but renewing the padding is slightly more difficult and is covered separately in the book.

Carrying out repairs
To examine the condition of the springing, turn the chair upside down and hold it steady by resting it on another chair or a workbench. Take off the hessian backing, using a chisel and mallet to remove the tacks which hold it to the frame; make sure you work very carefully in the direction of the grain to avoid damaging the wood. If the hessian is still in good condition, you will be able to use it again when you have completed the repair work. If, however, the backing looks worn or tatty, cut out a new one using the original as a pattern and allowing at least 25mm extra all around so you can make a neat, tucked-in finish.

Removing webbing
When you have removed the hessian, check the condition of the webbing – and the springs if there are any; some chairs have only a padded base supported with webbing. Look to see whether any of the webbing has come away from the frame or become saggy and slack through wear; if this is the case, remove it using the chisel and mallet to knock out the tacks. Try not to enlarge the holes when you do this; if you do open them up a little, fill them with a fine wood filler and leave them to harden. Once the webbing is free from the frame, use a sharp knife to cut the spring twine which holds the webbing to the springs, disturbing the springs as little as possible.

Replacing webbing
Turn over the end of the new webbing l9mm and, using the original tack holes as a guide, fix the webbing to the front edge of the frame with five tacks, placed in the shape of a ‘W’, so the wood will not split. You will need to buy a web stretcher, or make one by cutting a deep ‘V’ across one end of a piece of 50x25mm wood. Stretch the webbing across the seat and wrap it around the stretcher from end to end. Pull the webbing across the frame and lay the V-shaped end of the stretcher onto the edge of the frame at about a 45 degree angle. Press it down firmly until you feel the webbing will not stretch any more. Hold the stretcher in place and fix the webbing with a single row of three tacks. Remove the stretcher and cut off the webbing about 25mm from the tacks. Tum the end over and secure it with two more tacks. Again using the old tack holes as a guide complete the webbing along the length of the frame. Fix strips of webbing across the width of the frame, weaving them through the lengthwise pieces then stretching and tacking as before.

Fixing springs
To make sure the springs are secure and will not tear through the hessian, tuck each one under a place where two pieces of webbing overlap. If the springs tend to squeak, put a small piece of felt or some other kind of padding between the two parts of the spring which are rubbing together. When all the springs are in place, secure them to the webbing using spring twine and a half-circle or springing needle. Each spring should be fixed with four stitches equally spaced around it and caught at the same depth; finish off each stitch with a slip knot. Without breaking the twine, carry one stitch to an adjacent spring and stitch as before. When all the springs have been attached to the webbing in this way, finish off with a double knot and trim the twine.

Replace backing
Once you have renewed the seat padding, you can replace the backing. Fold in the edges of the hessian and tack it to the frame with three tacks in the middle of each side. Adjust any creases by taking out the tacks, straightening and retacking. When the hessian is flat, continue fixing it down with tacks every 50mm along the frame, avoiding previous holes if possible. Fold the hessian into shape around the legs and fix with tacks close together for a neat finish.

Button & foam cushion repairs

Some chairs and sofas have decorative buttons on the seat and back; these often work loose and fall off and can mar the appearance of upholstery which is otherwise in a good state of repair. Fortunately, replacing them is a relatively simple task. If only one or two buttons are missing, you could cover the new ones with pieces of fabric taken from an inconspicuous part of the chair or sofa; if several are missing, you may find it easier to replace all the buttons and cover them in a contrasting fabric.

Metal button trims
These, which you cover with fabric yourself, are available in a range of sizes from haberdashery departments of large stores. They are in two sections: the round main part has small claws on the bottom onto which fabric is pressed and the other part is a cap which clamps the fabric down and secures it in position. If you are using the same fabric, take a piece out of the underside of the chair or sofa or from the tuck-ins of the lower inside arms. You will find it worth experimenting with the fabric and the button trims until you achieve the correct tension across the button face. If the fabric is very thick, which upholstery fabric often is, you may find it very difficult to fit it onto the button trims. You can take the spare fabric to the fabrics department of a large store where you should be able to have the buttons covered at a reasonable cost.

Fixing buttons
When you are fixing a button to the inside back of a chair or settee, it is worth taking the back cover off so you have access to the inside padding. Thread a length of thin stitching twine through the button and then thread the two ends of the length of twine through the eye of a long upholstery stitching needle. Mark the position of the button with a piece of tailor’s chalk on the inside back cover, push the needle through this mark and through the inside padding, making sure the twine comes right through with the needle. Use a slip knot to join the two pieces of twine securely together; but before pulling the knot tight insert a small piece or tuft of felt or cloth between the stuffing and the slip knot to prevent the knot pulling through later and making an unsightly hole. Tighten the slip knot by pulling one end of the twine. At the same time check the other buttons already in place; if they are deep-buttoned (pulled in very tightly into the upholstery), make sure you match up the depth of the button you are fixing with their depth and pull in accordingly. When the buttons are all the same depth, tie a reef knot to stop the slip knot coming undone later; cut off the twine ends for a neat finish. Where it is not possible to take off the back cover without a great deal of trouble, you can make a quick repair with the cover on. Thread a long upholstery needle with twine and insert it into the upholstery on the side where you are going to replace the button.

Push it through until the eye has passed through the front fabric and the inside padding, leaving one end of the twine about l00mm long on the side where the button will be replaced. Push the eye back so it emerges close to the insertion point ; pull the needle and take off the thread. Pull in both ends of the twine and trim to even them up, leaving enough to allow you to make a slip knot. Take one end and thread the button on, fixing it with a slip knot and pulling in both ends of the twine to secure it tightly. Check the button is in the correct position and finish off with a reef knot. Cut the ends back as far as possible and tuck them under the button.

Reversible cushions
These can be rebuttoned fairly easily but the technique is slightly different. Since you will be working with buttons which have to be sewn in the same position on opposite sides of the cushion, it is best to remove the odd one on the opposite side to the one you are replacing so you can start from scratch. If the stitch holes have enlarged through wear, carefully stitch up this area using a fabric thread pulled out from a place on the cushion which is normally invisible. Fix the buttons slightly away from this point, making sure they are not drastically out of alignment with the rest of the buttons on the cushion, Where necessary, carefully mark new positions for the buttons on each side of the cushion. Thread a length of twine through a button and thread both ends of the twine through the eye of a long upholstery needle. Push the needle through the marked point on one side, guiding it through the stuffing until it locates the marked point on the other side; pull it out and remove the thread from it. Thread the other button on one end of the twine and make a slip knot joining the two twine ends. Pull the slip knot tighter until both buttons are pulled in to the required depth. Secure the twine with a reef knot under the button and cut off the ends as short as possible so they are hidden under the button. Make sure you do not snip the upholstery fabric at the same time.

Repairing foam cushions
When a foam-padded cushion begins to sag at the edges (usually at the front) you will find it a simple matter to strengthen it. If the cushion cover has no zip, find the edge of the cover which has been hand sewn and carefully cut along this edge to remove the stitches. Pull out the foam pad; you will need to squash it a little to free it from the cover. Where the cover has a zip, be careful not to catch the loam against the zip edges when you are pulling it out. Locate the damaged part and, using a sharp knife or pair of scissors, remove it by making a cut across the foam at least 75mm away from the damaged section. Use the damaged piece as a pattern for cutting a replacement piece from the same kind of foam material, allowing an extra 25mm. Coat the edges of the replacement part and the places where they will meet the pad with impact adhesive, making sure you do so in a well ventilated room since this material is flammable. Allow the adhesive to become tacky and bring the two surfaces together, pushing them firmly in place. Allow the adhesive to dry completely, fold the loam and push it into the cover. Where necessary, sew the cover edges together using a half circle needle to make slip-stitches.

Upholstery, cleaning & general repairs

It is worth getting into the habit of vacuuming your upholstery on a regular basis, since if you spring clean it once a year, dirt will be ground into the fabric. Most suction cleaners have a special attachment for cleaning upholstery and for removing dust and dirt from awkward places in the backs and sides of chairs. If possible you should remove any spillage immediately after it happens. Treatment will depend on the type of fabric, so before you begin always check the manufacturer’s instructions to make sure the cleaner you have in mind is suitable. You should check for such things as shrinkage and colour-fastness by making a small test with the cleaner in an inconspicuous place on the upholstery. To avoid over dampening the fabric and the padding beneath, it is best to use a dry cleaner on fabrics to get rid of spots and stains. This type of cleaner only wets the surface and dries very quickly to a powder; when you brush off the powder, it should take the stain with it. At least one make of this type is suitable for cleaning both upholstery and carpet.

Loose covers
These can be either dry-cleaned or washed, depending on the composition of the fabric. If you are in doubt, check with the manufacturer’s washing instructions or go to a reputable cleaner for advice. Some materials may be liable to shrink or run their colours in the wash and you should check for this before you begin washing.

Fixed covers
Very badly soiled areas in fixed fabric covers can be cleaned by using a special upholstery shampoo. Again, to avoid overdampening the fabric, you can use a dry shampoo with an applicator. The shampoo foam is forced through a sponge head in a controlled flow which eventually dries to a powder and is removed with an upholstery attachment on a vacuum cleaner. To make sure the shampoo will not harm the fabric, check on a small, hidden area first. Alternatively, if you are going to spring-clean yow carpets by hiring a hot water soil extraction machine, you can clean your upholstery at the same time. Ask for a special upholstery tool attachment when you are hiring one of these machines, which are available by the day or half-day from specialist hire shops and some carpet retailers. The machines are fairly heavy to manoeuvre; but this should not be a problem when you are cleaning upholstery, since you will probably be able to reach several chairs from one position. A shampoo is mixed with the hot water, ‘vacuumed’ over the upholstery with one sweep and sucked back with the grime and dirt in the next sweep, which takes out most of the moisture. It is best to treat very dirty areas with a spot remover to loosen the stain before starting to clean with the machine. The upholstery will dry out in a warm room.

Methods of repairing
Burst or frayed machine seams or tears near piping can be repaired by slip-stitching, which if done with care will conceal the damage. Neaten any frayed edges by trimming, but don’t cut into the fabric itself. If necessary, turn in a tiny piece along either side of the tom edges to make them neat. Use large darning needles fixed down firmly into the padding along the torn edges to hold them together while slip-stitching the tear. You will need matching strong thread and an upholsterer’s half circle ‘slipping’ needle, which you can buy from the haberdashery department of a large store or possibly an upholsterer’s shop. Tie a knot in one end of the thread and insert the needle into one side of the tear a little way in from the end, hiding the knot on the underside of the upholstery. Bring the two edges together by using very tiny stitches on either side, pulling the thread through very firmly each time and keeping the stitches parallel. Remove the darning needles as you go along and finish by fastening off the thread, working the thread end into the seam.

A hole can be successfully repaired by taking replacement fabric from elsewhere (from the underside of the chair or sofa, for example) and patching it in. If this is not possible and you feel it is worth the effort, try locating an extra piece of matching fabric from the manufacturer. Carefully cut away all the damaged fabric, tidying up the edges as you cut. The replacement patch should be slightly larger than the actual hole size and, where necessary, you should carefully match the pattern; if there is a pile make sure it is the right way up. Push the patch down into position onto the padding and underneath the hole edges. Coat round the edges of the patch and the undersides of the fabric edges round the hole with a fabric adhesive, taking care not to let the adhesive touch anywhere else. Wait until the adhesive becomes fairly tacky, press the two surfaces together and leave them to dry. This type of patch will satisfactorily disguise small damaged areas. For anything larger you will need to fit a replacement cover for that particular section: this is covered later in the book.

Leather and vinyl
Covers in leather and vinyl cannot be slip-stitched, but provided they are soft and well worn you can repair holes or tears with a special repair kit available from a hardware store or haberdashers. The kit enables you not only to match up the upholstery colour but also the grain, which is particularly important if you want to achieve a good repair. Clean the surface with white spirit to remove grease and dirt and insert a small piece of bonding sheet (provided with the kit) through the tear to form the base for the repair paste. Mix the paste to the exact colour and use a knife or spatula to spread it into the area. To match the upholstery grain use one of the patterns which come with the kit; alternatively for an unusual grain pattern you can use the rubber compound (which is also sup plied) to make a mould of an area identical to that which is damaged to provide a pattern. Place the grain pattern or rubber mould face down over the paste, place a piece of card on top and press down on it for two minutes with a warm iron to imprint the pattern on the paste.

Fitting a stair carpet

carpet fitters London staircase

Your stair carpet receives more wear than you might expect, so make sure you buy the right type and fit it correctly, for safety and maximum economy. When selecting a carpet for stairs, bear in mind the heavy wear to which it is going to be subjected. Most people do not realize how many times even a small family use the stairs every day. Wear is not only caused by treading but also by the scraping of heels against the risers and by strong rubbing against the nosing. Long pile carpets (for example shag and semi-shag) are not suitable for staircases and foam-backed carpets are best avoided, if possible, since they are complicated to install. As in all carpet installations underlay is essential since it provides longer life, increases sound insulation and gives greater comfort. Don’t use stair pads, which only cover the tread area. When fitting underlay, make sure there is enough to pass round the nosing of the stair. To give longer life, a stair carpet should be moved about six months after laying; this enables those parts of the carpet covering the risers to be placed over the treads and vice versa. Subsequently, at longer intervals, the carpet should be slightly moved to equalize the wear. When the carpet is laid, the extra amount is folded against the riser at the bottom of the staircase. Before fitting the carpet, make sure the natural inclination of the pile faces downwards.

carpet stairs

Measuring up
When buying a carpet, first measure the length you require. Assume the method of installation you are going to use will cause the carpet on the upper landing to overlap the top riser. Begin measuring from the base of the top riser and take the tape lightly over each tread and riser. Add to the total measured length an additional 38mm for each step to allow for the space taken by the underlay. Add a further 457mm to enable the carpet to be moved to increase its life. If the staircase includes a winder, measure along the path taken by the outer edge of the carpet.

Laying the carpet
The two main methods of laying stair carpets are by tacking down and by using tackless strip. Whichever method you use, it is necessary to mark on the stairs the positions of the edges of the carpet and the underlay; the marking for the underlay will also apply to the tackless strips when they are used. The purpose of this marking is to ensure the carpet is laid centrally when it is not wide enough to cover the stair fully. If the steps are 813mm wide and the carpet is 686mm wide, a mark should be made on the riser 63mm in from each edge. Then make a mark l9mm inside the first ones to indicate the width and position of the underlay and of the tackless strip.

Tack-down method
For tacking down a special type of tack is used which is less visible than the normal type. First attach all the underlay, using a separate piece for each step; the width should be 38mm less than the width of the carpet and it must be long enough to cover the tread and lap round the nosing so the lower edge can be secured to the riser below. Align the sides of each pad with the inner pair of marks and position the back edge 25mm in from the riser. Tack it down at intervals of 150mm across the back of the tread, stretch it over the nosing and tack it across the riser below. Starting at the top tread, position the end of the carpet as indicated by the marks so it is properly centred; allow an extra 13mm for turning under where the material reaches the top riser. Unwrap enough material from the roll to cover the first two or three steps. Before starting to tack, make sure the tuft rows across the carpet are parallel with the nosing. Turn the end of the carpet under so the cut end is not exposed and tack down one corner; stretch the carpet to make it even and

tack across the riser at intervals of about 100mm. Continue down the stairs stretching the carpet over the nosing and tacking the edges in at the crotch- Then insert tacks across the crotch at 100mm intervals- Where additional material has been included to allow for fitting the material is folded in and held against the bottom riser by tacking up the sides. A slight overlap is needed at the bottom end of the carpet so it can be folded back when the carpet is finally tacked at the base of the lowest riser; take “his into amount also when measuring the shifting allowance- The same is done to the overlap of the landing carpet which covers the top riser.

Tackless strip method
Tackless strip is a flat narrow strip of wood, which is nailed to the floor; it is fitted with pins at an angle onto which the carpet is hooked- For laying stair carpets the strip is sold in 762mm lengths, so to fit a carpet 686mm wide cut the lengths down. When installing tackless strips, first mark the stairs as explained above, then fix the strips on the stairs. One strip is nailed across the riser, parallel with and 16mm above the crotch. Another strip is nailed across the tread the same distance from the crotch; this provides a gap into which the carpet is tucked- These distances will have to be increased or decreased according to the thickness of the carpet sine it is important to ensure a tight fit. The pins of both strips should lean towards the crotch. Next attach the pieces of underlay, which should be longer those used in the tack-down method. The rear edge of the underlay butts up against the tackless strip on the tread and is tacked down. Then front edge is taken over the nosing stretched down.

Lifting floorboards

Because of the way floors are made lifting a floorboard is not always as straightforward as it may appear. Older houses usually have square-edged boards. These are not too difficult to lift, although some force may be needed.

Square-edged floorboards
To lift these check the surface of the board to see if it is secured with nails or screws; the screw slots may be filled with dirt so look carefully. If it is held with screws. the board will con-re up easily once the screws are removed; if nailed. it must be levered up. Start near the end of a conveniently placed board and insert a strong lever such as a long cold chisel, car tyre lever or flooring chisel into the gap between the boards. Hammer the chisel to prise up the end until another lever, for example a claw hammer, can be inserted under the board.

Work the two levers along the board until it is free. Alternatively. put a batten under the board. resting on boards either side, and hammer it along to avoid splitting the board or marking the next. Another method is to slip a length of steel pipe or rod under the end which has been lifted. Stand on the loose end and the leverage of the rod will force up the board further along its length. Keep moving the rod forward until the entire board comes up.

Tongued and grooved floorboards
The tricky part of lifting these boards is getting the first one up. Once this is out of the way the others can be lilted quite easily. To test for a tongued and grooved floor. take a thin-bladed tool, such as a screwdriver, and try to push it between the boards in several places. If the floor is tongued, you will not be able to insert the blade more than about 6mm . The best way to cut through the tongue (to release the board) is with a flooring saw, which looks like a tenon saw with a convex curved cutting edge. Cut right along the joint on one side and lever up the board as before. A circular power saw will cut through the tongue, but it makes a wide cut which may not be acceptable if the surface of the floor is to be left exposed. You can use a small pad saw, but take great care not to cut through electric cables and water pipes under the floor. To be on the safe side, tum off the electricity and the water. Cut with the blade at a shallow angle and use the tip to feel for cables and joists (which should be evident by the lines of nail heads).

Chipboard panels
Modem homes may have floors of tongued and grooved chipboard panels, which are very difficult to lift. The best way to remove an entire panel is to saw round the joints on all four sides using a powered circular saw with the blade set to cut 19mm deep. If this does not allow the panel to be lifted, increase the depth of cut to 22mm in case thicker panels have been used.

Cutting across boards
If there is not a convenient cut end at which to start lifting the board, make a cut across the board close to a joist. Look for the nail heads and use a thin blade to feel for the side of the joist. If you cannot get a blade between the boards, estimate the joist will extend 25-38mm on either side of the nails. Mark with a pencil a line across the board to one side of the joist. Drill three or four small holes at an angle away from the joist, just inside the pencil line, to enable you to insert a saw blade.

Using a pad saw or powered jig saw cut across the board , keeping the handle of the saw tilted towards the middle of the joist so the board will be supported when it is replaced. Give the board some additional support when you replace it by gluing and nailing a piece of scrap wood (50x25mm) to the side of the joist with clout nails 38mm long so its top is flush with the top of the joist.

Repairing timber floorboards

floorboards timber

Most homes have timber floors in upstairs rooms but in houses built in Britain since 1945 and in recent extensions to older houses – you will often find that the ground floor rooms have solid floors. As both timber and solid floors can be covered with wood blocks or plastic tiles it may not be immediately obvious which type you are dealing with. So always check first what sort of floor you have.
floor joists timber
Timber floors downstairs consist of boards or sheets of chipboard nailed over sturdy timber joists, which are often supported on low walls (called sleeper walls). Upstairs the joists may be built into opposite walls or supported in galvanized steel brackets (joist hangers). As they are supported on joists, timber floors are also called suspended floors. Unlike solid floors they make a hollow sound when stamped on and also have a certain amount of bounce. Another means of recognizing a timber floor downstairs is the presence of airbricks on the outside walls just above soil level.

These bricks allow air to circulate beneath the floor to keep it dry and free of rot. Solid floors at ground level do not have airbricks. Fixing loose and squeaky boards Loose boards move when you walk on them and will increase wear on any floor coverings laid over them. They may also develop annoying squeaks and creaks as two faces of timber rub together. To cure this, refix the boards by nailing them down properly. Possibly not all the nails were replaced the last the boards were lifted: more likely the nails are loose. Renailing with cut floor brads or round head nails slightly to one side may solve the problem. but there is a danger this will cause the end of the board to split. It is better to drill small pilot holes and refix the boards, using No l0 countersunk screws 38mm long. The screws must pass into the joists. the position of which can be seen by the line of nail heads on the surface of the boards. If the boards are properly fixed but still squeak because they are flexing, the problem can be temporarily overcome by dusting the crack between the boards with French chalk or talcum powder. If the squeak returns, one of the boards must be lifted and the edge planed to give slight clearance.

Sometimes boards which have been properly fixed to the joists still spring up and down usually because the joists themselves are not properly secured. The only way to check this is to lift some boards in the affected area and examine the joists.