Fitting a Fireplace

Fireplaces in period houses have sometimes been blocked in or completely removed. You can reinstate a fireplace with an appropriate grate.

Companies in our Products and Services Directory can dismantle, clean and rebuild marble surrounds. They can also provide restored and reproduction cast iron grates.

Look at the Design section to guide your choice of replacement grates.

The first step is to discover what you have. In most cases it will be obvious that there once was a fireplace in your house; there will be a chimneybreast with alcoves to the sides in most pre-1939 houses. In the 1950s some houses had the flue built outside the house so that will be obvious too.

If the aim is simply a decorative feature, then the absence of a chimney is no problem; otherwise a flue will be needed. If the chimney has possibly been removed, look in the loft for either a flue still there, or else signs of it having been removed; there will usually be chopped off bricks and a sooty strip. In either case, you will need the flue and chimney to be reinstated.

To reinstate a chimney can be a straightforward although major project. The removal process may be undoable e.g. the joists may have been extended with bolt-on pieces which can simply be removed. You will have to conform to modern building regulations regarding, for example, the depth of hearth. Speak to your building control people for advice.

The other debate will be on the bricks and mortar to use. The safest would be salvaged bricks and lime and sand only - then after any initial settlement, any movement will be sychronised. If you use cement, the more rigid chimney will crack at the joints with the old brickwork. When talking to builders, look for one who understands this.

Look under the carpet and see if there is a solid floor next to the fireplace; this is the hearth. This protects the wooden joists from fire. Knock on the chimneybreast. This may not reveal anything if the fireplace has been bricked up - it will be just as solid as the wall. If it is really hollow sounding then you probably have plaster board. Begin by chipping plaster off; cut a rectangle, say 10cm high and 60cm from the floor. Begin in the centre of the breast and work to the left and right. You are looking for bricks or stone used to fill the opening. Be careful not to damage the bricks or stone underneath. Once you have reached the boundary, work up and down, and then across the arch at the top. Note that the opening may be off-centre if there is a basement or other lower floor; the flue from a fireplace there will pass to one side of fireplaces in the rooms above.

What may you find? The possibilities are:

boarded up fireplace with grate in situ

Perfect. Check you have a chimney which has not been capped to seal it; you need good ventilation for an open fire. Get a sweep in; he or she will clean the flue and advise you.

boarded up fireplace with no grate in situ

This is a DIY job. A competent person can fit a new grate. A sweep can help and advise.

blocked fireplace with no grate

This is getting into non-DIY territory. If the blocking has been done with board or with bricks roughly mortared in, then you may be able to manage the work. Otherwise you need a builder because you don't want the wall above the fireplace to collapse. If there are cracks in the brick arch or a stone lintel, again get an expert.

completely rebuilt wall

You will definitely require a builder for this. Lift the carpet or other floor covering and check for the existence of a hearth. If missing, this will also need to be rebuilt.

no sign of a fireplace at all

This was a mistake; get a plasterer to cover it up again.

Once you have exposed the bricked up area, if you want to reinstate the opening, take a masonry chisel or bolster to the filling (a sledgehammer would be a bit too brutal). Aim centrally and make a hole, say 15cm square, and then explore up and down and side to side.

Whether you seek advice also depends on the use you are to make of the fireplace; just a decorative hole (with something sculptural, say), a gas fireplace or a real coal or wood fire. In the case of a gas fireplace, you will need a CORGI person to fit it so they can advise. For a real fire, you can speak to a specialist firm supplying salvaged or reproduction fireplaces. For a real fire, it is particularly important that the fireplace opening, hearth and chimney are in good condition. For example, the hearth must extend at least 500mm from the wall and be at least 125mm deep to reduce the risk of setting floor joists alight. These are governed by Building Regulations so the relevant bit of a local authority will have a view too. A sweep can tell a lot about the internal state of the flue, and can advise on whether the flue opening is adequately clear.

Costing the Project

If the chimneybreast has been removed, a full restoration will be fairly expensive; the chimneybreast will have to go back in the rooms above of course, into the loft and missing chimneys will have to be rebuilt. You will have to decide whether to build in a flue for the upstairs rooms, or whether to provide only one. It may be best to have two as the chimneybreast needs to be a similar width to the original otherwise it will look odd.

For the 'active' fireplaces, you will need a proper hearth (unless it has been left). The joists on the first floor and in the attic will have to be shortened again to fit them into the new flue.

And you will need reproduction or salvaged grates and surrounds.

For an estimate, work on £120 per day per person, a lot of bricks, some plastering, the hearths and joinery, plus the fireplaces. It will probably need 14-20 man-days per pair of rooms. The fireplaces will be say, £800-£1000 each for the main rooms, and a bit less for smaller ones upstairs. Add further cost if the chimney has to be rebuilt.

Reinstating a Fireplace

To reinstate a fireplace, for example from a gas fire:

  1. Have any gas flue vent removed from the top - you often see a little metal 'can' with vents in it. And replace it with a standard chimney pot. Either leave this open or use a louvered insert with a pot cap. This would stop heavy rain getting in.
  2. Is the gas fire set in a cast iron grate or has that been removed? If the former, just have it removed and check for any cracks in the cast iron, the mortar sealing it to the brickwork and the base of the flue; just use a torch and perhaps a mirror. If the latter, then choose a grate - either second hand or new, modern or old. If you go for old, see the Design section for what would be most appropriate. If you have one fitted, make sure they check the bottom of the flue for any obvious cracks.
  3. Make sure that the void between the grate and the wall behind is filled and a cement shelf capping this. If this void is not filled and capped, soot will accumulate, smell and possibly cause a chimney fire, and the vortex behind the grate will spoil the draught. To fill the void use a non-flammable material; use rubble and sand, and then sand and cement or sand and lime for the capping. Make sure the cast iron grate is sealed to the wall otherwise fumes and smoke will seep out; use mortar for this.
  4. Have the chimney swept.
  5. Get a couple of carbon monoxide detectors - the little round spot type will do and place these near the fireplace and in the room above.
  6. Light your fire and monitor the detectors for a few days. If you have any suspicions, then consider having a metal flue liner. This is fed in from the top. You will need a special type for a coal fire.

For companies specialising in this area, see the Products and Services Directory.