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.
Replastering
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.
Sealing
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.