Serious structural issue?

[briany]

For anyone with an engineering bent, I'm wondering about the rear wall of a victorian terraced house that I'm thinking of buying. There is a definite (not huge, but noticable) bulge at the rear wall, and I'm wondering how serious it is. The photo attached shows the location of the bulge, and the fact that there's a soil pipe in there suggests to me that there might be a long term leak into the wall fabric which has resulted in this bulge.
Might it also be just a symptom of age in the house? The whole house has definitely subsided to one side over the years (the slope in the floors and ceilings are testament to that), and this might be a contributing factor.
The other factor that I'm thinking about is that there isn't anything tying that wall at the centre to the rest of the house - the flooring joists run parallel to the front and rear walls, and all of the internal walls are lath and plaster. Might the wall simply be sagging under its own, unsupported, weight?

Really, what I'd be ever so grateful for is some advice on how serious this is. As I said, the bulge is noticable, but not dramatically so, and some settling over the years is to be expected and such idiosyncracies of individual houses are to be celebrated, so long as they aren't symptoms of imminent (i.e. sometime in the next twenty years) collapse. Would it be possible/advisable to put in one or more metal ties between front and rear walls, under the floors?

I realise that the advice of a good engineer here is essential, but engineers with skills in period property in Ireland are not easy to find, and I fully expect the stock advice to involve masses of concrete or demolition or both. Hence, I humbly solicit all of your valued and valuable opinions to arm myself with before bringing an engineer in.
Thanks ever so much,
Brian

 

[Lime]

briany what is the wall constructed with, brick or some other material?
What is the render made with, cement or lime?

 

[briany]

Lime, it'd be a random rubble stone wall with cement render (nicely cracked at the end, as you can see in the pic) on the outside, lime plastered to the inside, though I didn't inspect that too well. Well worth a better look from inside, I'd say.
Brian

 

[DaveBrigg]

My only, minor, comment would be that the cement was probably added some time after construction, so if it has cracked this suggests more than original settlement. From our experience, the render could be covering a bigger crack underneath, but we have a bigger bulges than this in our rear wall, and there is no sign of our house falling down at the moment. If you can look at the skirting board of the upstairs room this may show how much the wall is bowed, and from the state of any repairs or filling it may be possible to work out roughly how long ago the problem existed.

If, of course, the bulge is caused by the leaking soil pipe, I would stand a long way back before prodding it with a sharp stick

 

[christianb]

Hi Brian,

I've just seen something similar on a cottage I was asked to come up with an estimate for, as it happens. My guess is that it's probably a failure in the chimney breast, judging by the stack directly above.

If you personally know any experienced builders, get them to have a close look and give their opinion - it's almost impossible to tell from a distance.

Christian

 

[robgil]

is there a dividing wall behind that bulge? could be that an interior dividing wall butting up to the outside wall is pushing it out?

 

[BMcD]

It is possible the bulge is not so much the wall, rather the render having blown. The cracks at the corners of the windows are inherent weak spots for renders, allowing water in behind the render and being cement, not allowing it out. After a few winters of the water freezing behind the render, it will start to part company with the wall. If you can, give the bulge a tap with your knuckles and if it sound hollow, conpared to the rest, then it has blown. If not, call an engineer

 

[briany]

Interesting suggestions all. It'd be great if it was just the render blowing out, but that's a really good point about the stack. I looked at the stack side on from a distance, and it seemed somewhat twisted out of true, which may ideed be from the breast starting to give out. That'd be a fairly substantial job to rectify, I'd imagine... Might be a deal breaker. Is there any other way to check this?
It can't be internal walls, as they are all lath and plaster.
It's actually in lovely condition inside, by which I mean it hasn't suffered the depredations of the modern 'renovator' whose idea of perfection is to gut the place and replace with concrete blocks and PVC.
I'll have another look with a builder/engineer and I'll keep the forum posted.
Cheers
Brian