Laziness could be home's downfall; Removing a chimney breast needs careful planning, explains house doctor Peter Fall.
I KEEP saying to clients: "It takes a lot to make a building fall down." I say this from experience but maybe I also use a fair bit of hope.
I have yet to suffer a collapse or even a partial collapse in a building I have inspected. There have been a number of buildings I inspected after they collapsed and a couple where I insisted the client install supports pretty damn quick but none that fell down after I said they would be OK.
But never say never! This week found me inspecting a house where a "builder" (I will call him a contractor as to call him a builder is an insult to that trade) had, among other things, removed a chimney breast. He had stripped it back to the party wall from the ground floor up to the first-floor ceiling. Once plastered over you never knew it had been there - until you went into the roof space.
Our contractor, instead of removing the breast up to the top, had left it in place in the loft and propped up its outer edge with a length of wood which was in turn resting on the ceiling joists.
To fully appreciate the error of the contractor's ways we have to go back to first principles. When the chimney breast was constructed, it was carried by its own foundation resting on the ground. The bricklayer then built up a box with the flue down the middle, tying the bricks into the party wall. At no time did the original bricklayer envision it hanging off the party wall with fresh air underneath it. All of its weight was always to be carried by the foundations built into the ground.
When the original joiner decided how big the joists should be for the first-floor ceiling, he considered how far they needed to span then how much load they would need to carry. Being a ceiling it only needed to carry the plasterboard but knowing the average house-owner, he would allow a bit more for the decades of accumulated junk we all stash away in the roof space. He would not have allowed for the timbers to carry a load of brickwork, previously used as a chimney breast.
On that basis, why on earth did this contractor think that propping up one edge of what was left of the chimney breast on to the ceiling joists would be satisfactory? Why didn't he simply remove the rest up to the roof level? I can only put it down to laziness, cutting costs and/or he had no idea what he was doing.
In the short and maybe medium-term, it won't collapse, but one day it will. Its present state is down to a combination of some bricks being able to cantilever from the party wall and the ceiling joists not yet taking all of the load, but eventually gravity will win. This work should have been referred to Building Control as it's a structural alteration and as it's work to the party wall it should have had a Party Wall Agreement, but it doesn't. If the contractor had followed these routes this problem would not have occurred as the building inspector and the adjoining owner's party wall surveyor would have ensured it was done properly.
The solution now is either take the rest of the chimney breast out or fit steel joists beneath all three edges of the stack, building the joist ends into the party wall and making sure you don't damage next door's side of the wall! The client can then sleep easy in her bed underneath.
? Peter Fall, a chartered building surveyor, is a former president of the Royal Institution of Chartered Surveyors, tel: 0191 284 3467 or see www.peterfall.com