Removing a chimney breast

A fireplace chimney breast extends from its foundations all the way up to the flue pot. It is often an integral part of the house and sometimes the house next door as well – so you cannot simply cut it out without taking precautions to ensure that the remaining part of the house is structurally stable. Seek professional advice before starting this sort of job. The following notes do not tell you how to do it –

they simply state what the problem is. The most satisfactory approach from a structural point of view is to take down the entire chimney breast from the ground floor all the way up to the chimney pot and make good the brickwork, walls, floors, roof and so on. Obviously, if the chimney is shared this cannot be done, without the consent of your neighbours.

The alternative is to take half the chimney breast away but this immediately raises the problem of structural instability. When taking a fireplace and chimney breast away at ground floor level, you have to think about how you can support the chimney structure above. It is sometimes possible to do this satisfactorily, but each house has to be considered on its individual merits. It is usually quite safe to take down the upper part of a chimney – removing it down to roof level for instance (however even this cannot easily be done if the chimney is shared).


Minor repairs to a chimney can for access. Place sacks of rags or  Never attempt to carry out often be carried out using a con- straw under the roof ladder to pre- major repairs working off ladders.

ventional ladder with roof ladders vent damage to the roof covering.        Erect a proper scaffold.

Insecure or damaged pots

Pots are secured to the stack by a cement flaunching. Iftheflaunching has cracked or broken away it should be removed and replaced. Use a club hammer and bolster to break the flaunching. Lowerthe old

pot to the ground on a rope. Clean away the top of the stackwith a wire brush and, if necessary, repoint the top course of brickwork.

Wet the brickwork on top of the stack and the bottom of the new pot, place the pot in position then build up the new flaunching, one part cement to three parts sharp sand, to about 75mm deep around the pot. Trowel it smooth so that it slopes away from the pot in all directions.

Defective pointing

Defective joints should be raked outto a depth of about 20mm and all powdery material brushed away. Damp the brickwork before repointing with a mixture (just moist enough to be plastic) of one part cement to three or four parts soft sand with a plasticiser added to the water. Repointing is done by putting the mortar into a flat cake, cutting a slice the same width as the joint and then ,,.ding this into the joint.

Defective flashing

There are two major defects which occur with traditional lead flashing. The joint withthe masonry may be loose, allowing water to run down the back. To remedy this rake out the masonry joint, rewedge

the lead flashing using strips of lead driven into the joint with something like a blunt chisel, then repoint. The flashing may need replacing. This can be done with sheets of lead, zinc, aluminium alloy, a rigid bitumin-based material or with a purpose-made self-adhesive foil- backed flashingstrip. Remove the lower layers of roof covering to expose the edges of the flashing. Remove this with

a cold chisel and rake Out the mortar from the flashing joint to a depth of about 20mmor25mm. Shape the newflashing to match the old—use a sliding bevel to measure the angles. Wet the brickwork, place the newflashing in position and wedge it in the flashing joint. Replace the roof covering and repoint. Take the old lead to a scrap merchant.


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