Chimney breast removal and chimney stack work

Can you remove a chimney breast?

In most houses a chimney breast can be removed, provided whatever remains above is properly supported or removed as well. The chimney breast is the projecting masonry inside the room; above it may sit a further breast on the first floor, then the stack through the roof. Taking out the lower part alone leaves heavy masonry with nothing beneath it, so the design has to deal with every level the chimney passes through.

The usual options are to remove the breast on every floor and the stack above the roof, or to remove only the lower sections and support what is retained on a structural element designed by an engineer. Which is appropriate depends on the chimney’s construction, its condition, whether it is shared with an adjoining property and what you want to achieve in each room.

Chimney breast removal building regulations

Removing a chimney breast is a structural alteration, so building regulations approval is normally required. Building control will expect structural calculations showing how any retained masonry is supported and how loads reach suitable bearings. Supports that were once common, such as simple steel brackets, are not accepted by every building control body, so the support detail should come from the engineer for your property rather than a stock solution.

A completion certificate at the end records that the work was inspected. Buyers’ solicitors often ask for it when a house with a removed chimney breast is sold, so it is worth keeping with your property documents.

Shared chimneys and party walls

In terraced and semi-detached houses, chimney breasts are often built into the party wall and may back onto a neighbour’s flue. Cutting into or removing masonry in a party wall normally requires notice under the Party Wall Act before work starts. Flues serving a neighbour must remain intact and safe. These points should be checked early, because they affect both the programme and what can be removed.

Chimney stack removal

Chimney stack removal is sometimes carried out on its own, where a redundant stack is leaking or in poor condition, or together with removal of the breasts below. It involves scaffolding, taking down the masonry to below roof level, then infilling the roof with matching structure and coverings so the roof stays weathertight. Removing a stack can affect the appearance of a house, so planning advice may be needed in a conservation area or on a listed building, and a stack shared with a neighbour needs their agreement.

What the work involves on site

Work begins with protection and dust control, because chimney masonry holds a great deal of soot. Temporary support is installed where needed, the masonry is taken down in a controlled sequence and waste is removed. Any permanent support is installed to the engineer’s details, then the opening is made good: floor infill where the hearth was, plastering to the wall, skirtings and decoration. Ventilation of any retained flue should be considered to avoid damp problems later.

What affects chimney breast removal cost

Chimney breast removal cost and price depend on how many floors are involved, whether the stack is removed or supported, the engineering and approvals required, access for scaffolding, party wall procedures and the extent of making good. Removing a single ground-floor breast with supported masonry above is a different job from removing breasts on two floors and the stack. A site visit and the engineer’s design allow a written quote that reflects your chimney rather than a general figure.