Last updated: · Reviewed by Joachim Louw, CEng MIEI
StructuralEngineer.ie designs and signs off chimney breast removal for houses across Dublin, Kildare, Meath and Wicklow. Most Dublin semis and terraces built up to the 1970s have back-to-back chimney breasts on the party wall. Removing the ground-floor breast for space leaves the first-floor breast and the stack above with nothing under them unless support is designed in. Joachim Louw (CEng MIEI) checks what remains above, designs that support, and inspects it before it is covered.
The right answer depends on what stays: gallows brackets for a light breast and stack on a sound wall, or a steel beam or frame where the load is heavier or the wall is shared.
What happens on the first visit
On the visit the engineer checks what will remain above the removed breast (the first-floor breast, the stack, and anything built off it), the condition of the wall it bears on, and whether the breast is shared with or bears on a party wall.
- Check whether the first-floor breast and the stack are staying
- Assess the stack's height and condition from outside and in the attic
- Check the party wall construction and the neighbour's breast
- Look at floor joists trimmed around the hearth
- Check for flues still in use and ventilation needs
- Agree the extent of removal with you
Gallows brackets or a steel beam
Gallows brackets are steel angle brackets bolted to the wall below the retained breast. They're quick, but they only suit a light breast on a sound solid wall, and they rely entirely on the anchors and the masonry. A steel beam or frame carried on padstones into the side walls is the more robust solution, and the usual choice where the breast is heavy, the wall is weak, or the bearing is on a party wall.
Either way, the calcs come with a propping sequence. The breast is supported before any brick comes out below it.
Party walls and selling
Most chimney breasts sit on the party wall, so the work affects your neighbour's structure. The Land and Conveyancing Law Reform Act 2009 (sections 44–45) sets out your rights and obligations for works to party structures. A buyer's solicitor will also ask about a removed breast, and an opinion of compliance based on an inspection of the support before it was boxed in answers that.
What's included
- Site visit by a Chartered Engineer
- Assessment of the retained breast and stack
- Gallows bracket or steel support design
- Padstone and bearing checks
- Propping sequence for the builder
- Party wall considerations noted
- Inspection before boxing in
- Signed opinion of compliance
Fixed fee confirmed in writing before the visit.
Brackets by eye, removal without support, or a designed solution
What holds up the chimney after the breast comes out.
| Check | Brackets by eye | Removed without support | Engineer-designed support |
|---|---|---|---|
| Weight of the retained breast and stack assessed | No | No | Yes |
| Wall capacity checked | No | No | Yes |
| Propping before removal | sometimes | No | Yes |
| Certificate a buyer's solicitor will accept | No | No | Yes |