Building brickwork arches

• Types of brick arch
• Designing an arch
• Choosing the correct bricks
• Erecting and reinforcing a Soldier arch
• Ringed arch construction: building plans, erecting a former and bricklaying
• Pointing and finishing off

brick arch

First measure across the opening and note the proposed position of the bricks (do this on both sides of the wall if you are erecting two arches). Using this information, try to place the key or middle brick—directly over the centre of the opening and so avoid having to place a shorter, cut brick at one end of the arch. Mortar each brick into place carefully and place a straightedge across the face of the wall while you are building to ensure that the arch is correctly aligned. When you have finished, leave the mortar to set for three to four days.

Then carefully life-size plan of the intrados arc on a large piece of paper or card. Measure across the springing line at the top of the opening, then go to the paper and draw a line of the same dimension across the bottom of the sheet. Mark the midpoint of the line carefully and this will give you the striking point of the arch. With this, the base line of the arch, marked, use the striking point as a centre and draw a semi-circle above the springing line with a large compass or a pencil tied to the end of a piece of string. Then lay a square or protractor along the springing line and draw a line up from the striking point which bisects the half-circle.

This gives the exact position of the key brick. Use the half circle and the perpendicular line running up through it to mark the position of each brick on the plan. Make sure all the bricks face inwards towards the striking point and that they are separated by neat, wedge-shaped joints. Once the plan is drawn out—using one or more rows of brick—it can be used to calculate the exact number of bricks needed to complete the job. Remember, though, that the total has to be doubled in a cavity or double thickness wall where the arch has to be reproduced on both sides of a door or window opening.

Former construction: To construct the former, you need a sheet of 15mm plywood to make up the rounded sides and the soffit plus a piece of hardboard to go across the top. Mark the two semicircular side pieces first, to the same dimensions as the plan. Cut them out carefully using a fretsaw. Then cut a third piece as wide as the soffit—excluding the two side sections—and as long as the opening. Attach the three pieces together by nailing along the bottom of the two side sections into the edge of the soffit section. With the frame completed, pin a piece of hardboard as wide as the soffit across the top and make sure that it is flat and level with the two sides . After you have rechecked the former against the original plan, locate it in position across the top of the opening.

Supporting the former: To hold the timber former in place during construction, you must build a small frame to fit underneath. This should consist of two side pieces with one wider cross-piece which fits across the top—although in the case of particularly wide soffits two frames may have to be built, one for each side. First measure the distance from the ground to the springing line. Subtract the width of the cross support, then cut two side bearers from 50mm square timber to this size. Fix the side bearers to the brickwork in the middle of the soffit using masonry or galvanized nails. Next, lay a piece of flat plywood almost as wide as the soffit across the top of the side bearers. Check carefully that it is correctly aligned with a spirit level and then place the timber former on top. Finally, cut four folding timber wedges and drive two from each side between the cross-piece and the side bearers. These allow you to make minor adjustments to the position of the former during construction and make it easier to remove it after the mortar has set.

Building the arch: To help keep the arch brickwork level with the face of the wall, nail four flat boards about 500mm long on each side of the opening extending from the top to the bottom of the arch. Then attach a string across the bottom of each pair of boards to act as a guiding line this can be moved up as building progresses. Start at the bottom of the arch, building each side at the same pace. As you position each brick check— with the help of a line stretched up from the striking point—that it is correctly positioned according to the original plan. Try to make neat, wedge-shaped mortar joints between each brick by putting more mortar on one end than you do at the other. Alternatively, insert small wedging pieces of slate between each brick and leave them permanently to set with the mortar.

Continue upwards until you reach the key brick, raising the guiding lines as you go. Check carefully that the final bricks are positioned correctly, especially the key brick which sits directly above the middle of the opening. Leave the mortar to set for at least three to four days—then knock away the folding wedges and remove the former. Finally, pull the side supports away from the wall and point the brickwork on the arch. Take great care when you are building or rebuilding the brickwork around the top of the arch, and use the lines you erected earlier as guides. Try to ensure that each brickwork course meets the sides of the arch neatly, and cut any bricks to fit with a hammer and bolster. Point around the outside of the entire area and then while the mortar is still wet run a soft brush across the surface.

Removing a fireplace and blocking up the opening

Removing a fireplace and blocking up the opening is a relatively straightforward job providing you plan the work carefully and have the right tools and equipment to hand. If you don’t want to pay for professional builders in London, we offer you a small guide.
To remove the surround, hearth and fireback use a crowbar, club hammer and a bolster. These should be adequate for prising the various parts free of their fixings without the need for excessive force, but you will need safety glasses or goggles if you have to hack away mortar with the bolster since loose material is bound to fly. Where the surround is screwed to the wall or chimney breast you also need a large screwdriver, plus a hacksaw to cut through any fixings which cannot easily be shifted. Bear in mind that the hearth and surround are likely to prove heavy and you will need the help of at least one other person to dispose of them.

An assistant can also help by steadying the surround while it is being levered free of its fixings. Once all the equipment has been assembled, clear the room ready for the work. Removing the fireplace will create a great deal of rubble and dust, so it is best to take everything out of the room, including the carpet. Sheet polythene can be bought in large rolls to completely cover the floor and protect it while the work is going on. If the fireplace is near flat surfaces such as window ledges or built-in furniture, cover these with newspapers and masking tape. A number of heavy-duty polythene bags are useful for disposing of the loose rubble and soot created during demolition and clearance of the site.

Removing the surround

Since the surround is likely to be resting on top of the hearth it is best to start by removing this. The technique you use will depend on how the surround is constructed.

Tiled surrounds:

Here the first task is to remove the plaster covering the two fixing lugs. To do this start at the top right hand corner of the fire and chip away the plaster using a hammer and bolster. When you have uncovered the fixing lugs, ask a helper to steady the fire surround while you undo them.

Sometimes they will simply unscrew from the wall; if not, cut them off at or near their junction with the wall using a bolster or hacksaw. With your helper still steadying the far end of the surround, use your left hand to steady the other end and hold the crowbar in your right hand. Insert this between the surround and the chimney breast, somewhere near the base. If the surround moves by even a few millimetres there are no more fixing lugs. If not, there may be fixing lugs at the bottom edges which should be removed before you proceed. Once you are sure that all the lugs are free, slowly lower the surround to the ground in front of the fire. Two people can usually carry the surround outside to be disposed of, but i f you have to negotiate a stairway or an awkward doorway, get some extra help.

Removing a timber surround:

The procedure used to remove a wooden surround is much the same as for a tiled one except that the fixing lugs usually face towards the fire opening rather than outwards away from it. Start by taking the crowbar and driving it between the wooden part of the surround and the brickwork behind it. By levering with the crowbar and using your hands to pull the surround away from the wall you should be able to open a gap between the surround and the wall big enough to look down.

Check whether the timber is held in place by any other fixings—either metal studs or bars. If not, simply lever the facing away from the wall and pull it clear. If there are other fixings, work your way around the edges of the facing gently levering it away from the wall; do this a small amount at a time to avoid damaging the wall and cracking the brickwork. If the fixings refuse to pull clear, insert a hacksaw between the facing and the wall and cut through the studs or bars.

Removing a brick surround:

A stone or brickwork surround is easily removed with a hammer and bolster one course at a time. Starting from the top, insert the bolster into each of the layers of mortar. Then gently tap each brick free and remove it by hand, out of the way. You may come across steel ties bridging the two walls in which case work these loose by knocking them gently backwards and forwards with the hammer then pull them free with your hand. Continue downwards removing the soldier arch and steel support as you go until you reach the fire hearth.

Levelling the hearth

Most hearths consist of a slab of concrete—usually covered in tiles— which sits below the opening and is bedded into place on a weak limemortar mix. If the bottom of the hearth is level with the surrounding floor loosen the bedding mortar by chopping around it with a hammer and bolster. Then insert the crowbar under one end of the hearth and raise it high enough to push a thin batten of wood underneath. Do the same with the other side and you should be able to lift the whole hearth away with the help of another person.

However, if the hearth is lower than the surrounding floor, you have no choice but to break it up or chip it away down to the required level using a hammer and bolster. Removing the fireback The fireback is usually held in place by a bed of mortar laid against the edges of the opening. It is usually old and crumbly so if it does not immediately pull free, use the hammer and bolster to break it into more easily handled pieces. The cavity above will be full of soot and rubble and you should make sure that this is removed and the opening brushed clean before you continue.

Blocking up the opening

Once the fireplace has been knocked down and the area cleaned, the opening should be blocked off to prevent draughts and to stop dust falling down the chimney into the room. For this you can use bricks, lightweight building blocks or more lightweight materials such as hardboard, chipboard or asbestos. In order to bed the blocking material into place and allow a neat plastered finish, you need to cut away some of the existing plaster around the opening with the hammer and bolster.

If you decide to retain the present surround, first break out the fireback and then cut away the plaster around the opening to a distance of about 200mm on each side. Try not to damage the brickwork underneath as you do this and leave straight edges around the area you have cleared away so that final plastering is made easier. What you do next depends on whether you block up the opening with bricks or some type of sheeting. But whatever method you use, the blocked opening must contain a ventilation grille, fitted at a distance of about 100mm from the floor.

Bricking in:

Bricks and lightweight building blocks are both perfectly adequate where you want to block up an opening permanently. But if the opening is particularly small, bricks are preferable since they are easier to manoeuvre and fit into place.

First prepare a mix of 1:4 mortar and lay a bed of it on the floor between the existing wall. Then build up each course of bricks.; remember to leave a gap 100mm from the floor to accommodate the vent. As the wall is built upwards, hold a straightedge against the face of the brickwork to check vertical and horizontal alignment. Any bulges and indentations should be corrected and adjusted before you continue.

Build up successive courses until you fill the cavity. The gap on the last course may be too thin to take whole bricks, so you should cut them lengthways to make up the difference. Finally, look over the new brickwork and fill all gaps to create a smooth and flat surface. Leave it to dry out for 12 hours before plastering. Boarding up: For this use 6mm oiltempered hardboard, chipboard, or if you intend to fit a gas fire in front of the wall, asbestos sheeting. Measure and cut the sheeting to size, and make an internal hole to take the ventilator using a drill and a padsaw. When cutting and drilling asbestos, make sure you wear a mask to avoid breathing in the dust. Fix the sheeting into place by marking and drilling holes along its edge and using wall plugs to secure it to the wall beneath. If necessary pack it out to bring it nearly level with the surrounding plaster.


Before plastering make sure that the surface is prepared properly and that old and flaking plaster is stabilized. Check brickwork for loose mortar: strengthen any crumbling joints then chip away excess mortar once this has dried. Try to plaster the area neatly by feathering off around the edges. Once both coats of plaster have been applied and allowed to dry thoroughly, the ventilation grille can be fitted and fixed firmly in place with bolts or self-tapping screws. Although the plaster may dry hard after about 20 minutes, it often takes months to settle on the brickwork below; consequently, redecorating, especially with wallpaper should not be undertaken straight away.


Disused fireplaces often run the risk of penetrating damp as a result of rain falling down the chimney. The simplest way of avoiding this is to fit a rain bonnet, a blocking piece which is cemented into the chimney pot. The bonnet effectively stops rain entering the chimney, but allows air to circulate freely. Alternatively, you could remove the chimney pot, cover the opening with slate and then seal it with mortar flaunching.

In this case, though, ventilation must be provided in the form of an airbrick in the chimney stack. The brick should go as high as possible, preferably in the roof space. Note that in the UK, sealing a chimney constitutes a structural alteration and you will need building permission from your local Building Control office or District Surveyor. He will want to know how the sealed chimney is to be ventilated and also what alternative methods of heating are being used.

Fireplace installers in London

London powers ahead of the UK

London is home to over eight million people. It is also called the capital of the world. The economy of the city itself, it is extremely unconnected to the rest of the United Kingdom, a Vatican style cosmopolitan city. At a time when the rest of the UK and Europe suffers from job loses and property prices falling, London seems to be immune to the economic recessions that plagues the rest of the world. The employment is rising in London according to the latest figures, balancing the figures for the rest of the United Kingdom, where job loses are increasing.The property market in London is a perfect example to illustrate the contrast between the city and the rest of the UK.

London Big Ben

The properties in London alone, are worth more than the rest of the United Kingdom added together. Investors from all over the world, from Russian oligarchs to anyone who has money to invest follow the principle : safe as houses and invest in the brick and mortar business. London Olympics also helped grow the economy of the city state like, despite the recent riots. Massive construction projects have taken place, and many more are being planned by architects. Building works like the Shard , the Olympic village , Crossrail project, etc , are providing the city with investments into the property market and infrastructure.

And then there is of course, The City of London , the truly financial capital of the world, home to the bankers and financial business. Statistics show that most Londoners contributes 70% more to the national budget than the rest of Britain. But there is also a darker side to the statistics. The quality of life for Londoners is well below the standard for the rest of the UK. People work harder and longer, the so called rat race is the norm and everything is more expensive. For most homeowners in London, maintaining a property will cost them about 40% more than the rest of the UK. A plumber or an electrician will charge a small fortune and the cost of building a house extension or a loft conversion in London, can buy you a whole street in Liverpool, where £1 houses were put on sale recently by the local council, on the condition that the buyer will refurbish the property and has experience in a building trade.

In London, Battersea Power Station has been purchased by foreign property development and a decent sized apartment is expected to cost more £ 1 million. Because of the high demand of residential properties in London, some 800 apartments have been promised to be sold to British buyers, but foreign buyers will have the chance to buy a flat ahead of British buyers from London. The wife of the new governor of the Bank of England, recently complained that is impossible to find a place to live in London having a budget of less than one million. This summons the development of London in the United Kingdom, a two speed economy in a single country.

Installing a lintel without using Acrow props

Installing a lintel without using Acrow props might sound a bit risky and it could be potentially dangerous, but a new invention came onto the market.

removing load bearing
Traditional way of removing a load bearing wall using Acrow props

However, when removing a load bearing wall, using acrow props still is the safe way to fit a lintel or an RSJ beam.

Injecting a damp-proof course

Rising damp is an unpleasant and destructive problem which must be tackled as soon as it is discovered. However, by adapting a common garden pressure spray you can instal a chemical DPC quickly, cheaply and efficiently

Rising damp is one of the most serious problems affecting older houses. It ruins decorations, creates an unpleasant atmosphere, causes musty smells, and threatens any adjoining woodwork. And the continued presence of damp in walls is likely to lead to either wet or dry rot in skirting boards, door and window frames, and structural joists. Most houses built in the UK before 1875 were never given a damp-proof course (DPC). And many newer properties have DPCs which have failed through being breached by settlement cracks.

Traditional DPCs consisted of a layer of either slate—which can crack—or bituminous felt—which can become brittle and crack after a time. Slightly less common was two or three courses of hard engineering bricks (which are impervious to water).

There are several ways of installing new DPCs in existing buildings:

dpc walls

• It is possible to cut out a layer of mortar and insert bituminous felt or plastic DPC.
• Ceramic respirators can be inserted into the brickwork to carry damp away by evaporation.
• Copper wires can be plugged into the wall to drain off the tiny electric currents which encourage water to rise up the wall.
• The bottom courses of the brickwork can be injected with a siliconebased fluid. For the DIY enthusiast, the last method is by far the easiest and most certain way of dealing with rising damp. The first method, although by far the most effective, is not practical for the average home owner.

The silicone injection system

Silicone is basically a wax with powerful water-repellent qualities and in DPC fluid, it is dissolved in a spirit base together with anti-fungal additives. To treat brickwork, holes are drilled into the walls, interior and exterior, all around the house at a certain level. Then the DPC fluid is pumped in until it displaces the water in the brickwork. Finally the spirit base evaporates, leaving a waxy gel inside the pores of the brickwork and mortar. This cuts off and reverses the wall’s natural capillary action, forcing damp downwards and preventing the passage of external moisture.

Silicone DPCs are best installed in brickwork but they can be used also in some types of stone; they are effective for walls up to 450mm thick. A variant on the standard fluid contains a metallic additive which is specially formulated to provide a DPC through the rubble infill found between the two skins of brickwork in older, ‘puddle’ walls (though these are rare). Identifying rising damp If your house either has no DPC or appears to have a faulty DPC you must remedy the situation as soon as possible to prevent damp spreading. To start with you should try and discover the age of your property.

If it was built before 1875 there is almost certainly no DPC but of course, newer houses may also lack one. Look for a dark layer of slate between two courses of bricks near ground level. The presence of rising damp is indicated by a number of possible symptoms: rotten wood at ground level; decorations stained by a water tide-mark, spreading upwards; soft, decaying plaster; mould or fungus growth on wall surfaces; wallpaper lifting from the wall or an unpleasant musty smell. But it may be that the damp is caused by something relatively trivial, which can be remedied without recourse to a silicone installation. One possible cause is a pile of earth that has bridged the DPC.

Another is a crack in the brickwork which runs through the DPC. In this case the remedy is simply to repair the crack and the DPC locally. One common cause of damp is the DPC being bridged by external rendering which has ‘blown’—worked loose— allowing moisture to travel up the wall by capillary action.

Pre-installation treatments

The way that you tackle rising damp depends to a large extent on the construction of the lower floors, and on the type and thickness of the walls.

Solid floors: These may be wholly solid, concrete surfaced with tiles, or stone. They must incorporate a dampproof membrane (usually a sheet of heavy gauge PVC or a layer of black bitumen-based compound) which meets up with the DPC.

solid floor DPM membrane

To test for rising damp in solid floors make a ring of putty on the floor and then press a sheet of glass firmly on to the ring in order to form an airtight seal.

If there is no adequate damp-proof membrane, condensation will form beneath the glass within a few days. A cheap and unreliable way to fix floors which lack a damp-proof membrane must first be levelled with a self-levelling compound and then painted with two coats of damp-proofing fluid.

If there is a damp-proof membrane, make sure that it continues some way up the wall; if it does not, the margin between the floor and the wall must be treated before any replastering and after the DPC installation. Having cut away the damp wall plaster—to a height of at least 200mm above floor level—fill any gaps that are left in the brickwork with mortar containing a waterproofing additive. Then paint at least three coats of bituminous fluid along the outer edge of the floor, over the filled gaps, and at least 150mm up the wall. Take care to leave no gaps: damp can rise through the smallest gaps and thinnest layers.

Suspended floors:

suspended floor damp

There are two main types of suspended floor. In type 1 the joists rest on a sleeper wall and in type 2 they are set into an exterior wall. Check which kind you have simply by lifting a couple of floorboards near to the edge of the floor and looking for the presence or absence of sleeper walls with a torch. Type 1 floors are much less threatened by rising damp than type 2 because usually there is a thin bituminous layer between the brickwork of the sleeper wall and the timber itself. Push a knife into the timber on top of the wall which supports the floor joists (the wall plate): if it resists the blade you can be sure that it is free of rot. In the case of type B floors you must test the joists themselves and use a torch to search for any signs of fungus and rot. In the case of wet rot in type 1 floors you must completely replace all affected timber, then instal a DPC in both the sleeper and the outside walls.

If you have dry rot then you should call in a specialist firm to carry out the treatment. Make sure that the DPC is at least 150mm above the ground level in order to protect the walls, skirtings and decorations. If the timber shows no signs of rot, simply spray the timber with a preservative. In the case of a sound type 2 floor with no DPC you must instal a DPC in the outside wall from below the joists to 150mm above ground level. This may involve lowering the ground level around the walls a little. But where rotten timber is encountered you must replace all the affected floorboards and joists, and spray the rest of the timber with a preservative. If you are in any doubt about the presence of dry rot, spray both the timber and the masonry with dry-rot fluid.

Walls below ground level:

It is not possible to instal an effective DPC in any walls below ground level. However, in cases where there is a different ground level against one side of the house, there are two possible alternatives. One method is to instal a continuous DPC following the ground, with ‘verticals’ linking the different levels. In this case any walls which cannot be protected by the DPC interior wal must be tanked internally against the damp. This is done with waterproof cement or bitumen waterproofer and is covered further on in the Repairs and renovations course. The better method where the walls make direct contact with high banks of earth is to dig these away and form a trench around the house. Also, if possible, construct a small retaining wall to hold back the earth. You can then instal a continuously level DPC, which is less prone to being breached.

Installing the DPC

Professional installers pump the silicone fluid into the wall but although the pumps can be hired they are messy and tend to waste much of the fluid. Conventional DIY practice is to decant the fluid into the wall from inverted bottles and although this method involves little effort, penetration may not be thorough. Probably the best method for allround ease and efficiency is to inject the fluid from an ordinary garden-type compression spray. With this you simply remove the nozzle and insert the hose into a home brewing bung matched to the size of your predrilled holes. The DPC fluid itself is generally available in 25, 5 and 2.5 litre drums.

You will need about one litre of fluid per 300mm length on an average, solid (225mm) wall. Because you will need to drill a great many holes in the brickwork, it makes sense to hire a medium sized rotary hammer drill with pneumatic action and a clutch to save fatigue and jams. Buy a carbidetipped masonry bit to match the thickness of the bung you are using, and make sure that it is long enough to penetrate the wall at an angle. Use bungs between 16mm and 20mm in diameter.

Preparing the walls

In order to ensure the success of the treatment you must remove any old or unsound plaster, the first 150-200mm of rendering, and repair any cracks in the wall. Pour a thin mixture of concrete grout into any cracks and allow it to set before injecting the DPC. Similarly, rake out and replace any crumbling mortar, and replace any badly damaged brickwork. Note that old plaster on the other side of a party wall can bridge your DPC. In this case, you must tank the party wall up to at least lm from the ground and if the damp is particularly bad, extend your DPC over three courses of brickwork.

Tea for builders

Builder’s tea is an English colloquial term for the sort of strong, inexpensive tea drunk by construction workers taking a break. It is usually served in a mug. Or you can just ask the builders to hold a tea bag in their mouths while you pour the hot water – if you don’t like them.
tea for builders

Building London

First transmitted in 1964, this film charts how London has grown in size and spread into the surrounding country. Written and narrated by architectural critic Reyner Banham, A City Crowned with Green describes the unique character of London as a capital city.

Banham looks at how it has, from the time of Elizabeth I, defied the efforts of the planners to curb its growth but he is alarmed by the urban sprawl. Is to too late to get back closer to the heart and make London a city crowned with green?

History of London, from London City to Greater London on BBC website.

Reinforced brickwork and walls

It is often useful to incorporate reinforcements when working with bricks or building blocks. Applications include extension walls, block partitions and free standing garden walls. Apart from rolled steel bars, which are occasionally used for vertical reinforcement, nearly all the reinforcements employed in brick or blockwork are inserted on a horizontal plane.

Stainless steel helical bars are widely used for masonry repairs, crack stitching and general brickwork reinforcement

Used in this way, they can make up for unavoidable breaks in bonding patterns or add strength to corners and changes in section. Single skin block structures are less sturdy than their brick equivalents and reinforcement is nearly always specified by the architect or building inspector and Specifications must be followed by the builders.

All are mortared into the bedding joints as brick or block laying proceeds. Expanded metal, light mesh, or tramline reinforcement can be used between brick or block courses while twisted metal ‘butterfly’ ties are generally inserted across the line of the brickwork on a double thickness or cavity wall.

Strengthening house walls

The walls of most modern houses, extensions and outhouses are built in two layers with a cavity between. The inner wall is usually made of lightweight building blocks while the outer wall consists of bricks. To hold the two leaves together, steel wall ties must be built into the mortar joints between them.

To strengthen the wall further, particularly if the building is higher than one storey, reinforcement must be added at certain weak points in the structure. These occur at changes of section in a brick wall, particularly above doors and windows. To strengthen these points, two lines of reinforcement should be added to the first one course above the opening and the second three or four courses higher up. The reinforcement should extend 600mm either side of the critical section. And where two openings are in close proximity, the strengthening will bear the stresses better if it is positioned in two lines above and between the openings.