We are renovating a 250 year old granite terraced cottage, and when we have gone to strip back and replaster the room on the 2nd/attic floor (which was converted to bedrooms years ago) we have found this (see picture) at the top of one gable wall. The granite and the brick sitting on top of the party wall appear to be what is supporting the chimney stack on top of this party wall, but our builder is concerned the mortar is not pretty non-existent on bothe the granite and the brick parts, and some of the bricks are missing/very loose. He’s also concerned about the purlins, as he says the end of them is not really supported by this. We’ve not seen any major problems with the party chimney from the outside, but as it’s 3 storeys up we can’t get a really good close look, but it’s certainly not leaning. Our builder is recommending rebuilding the whole stack from the bottom (ie the brick in the loft room) all the way upwards and including the stack above the roofline, but is this really necessary? It is a listed building, and as it’s a party wall and chimney we would need to liaise with lot so of people to do this and it would also therefore really hold up the rest of our renovation project. If we leave it are we asking for disaster? Is there a compromise of improving the pointing or in some way supporting the external stack better? The chimney isn’t used any more, if that makes any difference! Would appreciate some advice on whether I should really be panicking or being relaxed!
I'm no expert, but if that was mine I would be worried too.
I'd opt for the hassle sorting it out because its listed is nothing compared to the hassle you'd get if it fell through into you while your sleeping below.
IMO it needs further investigation, including getting up to to look at the rest.
no need to get excited. its been there for a bit alreadyand still standin.
as its a listed building save yourself future grief by contacting the conservation people now
they have lots of good advice and can be well helpful. so do BCO's
cant make sense of the chimney. wheres the gable? is it a neighbiurs loft beyond the bricks? it looks like its a party wall.
any masonry rebuilding will have to involve with the neighbour.
are you goin to remove the roof or the ceiling? how did you expose this, was there a stud wall blinding and maybe supporting at that end of the loft?
can you show front and back photos of the stack from outside?
theres no short cuts because you have safety and listing issues and you must thinkk in terms of far more work than you bargined for.
did you have a mortgage survey?
Looks even worse than the stacks on my little project- good odds if you took the load off it (the purlins and ridge beam) you'd be able to lift the bricks and stones off- no hammer required!
As long as no external lateral forces come into play it'll be fine- if you choose to leave it be then every time the wind blows a bit hard you'll be fretting. Add earthquake risk to that (I don't know where you are but granite smacks of Scotland to me & there are occasional earthquakes up there) and you'll be on for some sleepless nights.
Probably a foolish question but did your survey not pick up on this little issue? Obviously you're in a world of financial pain anyway when it comes to working on a listed building- is there any grant aid available (to prevent a chunk of priceless heritage falling down)? Your builder is quite right- it needs taking down as far as you need to go (when you can't lift the bricks off is a good sign) and rebuilding with lime mortar and the original bricks and stones (to maintain the listing). With luck you won't have to take the roof off ( builder will need to prop down to ground level to support the roof before he can drop and rebuild the wall) so it isn't a showstopper- just a massive pain in the bum. Not sure if the Party Wall Act applies where you are- you might want to talk to your neighbour anyway, if the brickwork their side is in the same state then you might be able to persuade them to split the costs.
You obviously need to look in the neighbours loft as well, and see how bad their side is. The granite blocks look as though a bit of mortar wouldn't go amiss, and I'd then start removing the bricks, and cementing them back in as I go. Looking at that lot, they've attempted supported the purlins, but haven't done a great job, so I'd do the support properly, then as long as you go carefully and methodically, I doubt that it can get much worse than it is.