Cracks in exterior rear wall (more tales from the house that bodger built)

[Seri]

Okay, I'm not expecting a huge ammount of helpful replies as I fear it really is one of those things that needs to be seen to be diagnosed (I intend to get a surveyor out soon).

This old victorian house of mine has a fair few ailments which I'm slowly sorting out and making good, some caused through age but by far the majority caused by the previous owners.

Issue: The rear exterior wall of my building has some fairly major cracks in it running away from the corners of the back door and also from the corners of the small (absolutely tiny) window in that wall. This wall doesn't bear the load of the house as such as the beams run width ways into the side walls. The cracks don't seem to be getting that much bigger, but when we purchased the house the wall that was affected was tiled on the inside and rendered on the outside which effectively concealed this problem.

The last owner of this house had a bit of a fetish for concrete, and didn't like to waste an opportunity to use it, there is a small roofed area at the back of the house and this has a concrete floor. This floor itself has now developed some holes and cracks in it, the holes actually go down to a recess area which I assume is simply a small level of compression of the underlying ground in that area caused by having ten tons of concrete sat on top of it.

My question is really, is it a possibility that this concrete floor outside the back of the house which connects straight to the rear wall is pulling down on the wall and causing the cracks?

Any advice or opinions are gladly welcomed.

Thanks

Seri

[dg]

No it is not very likely that a floor slab is causing the cracks.

dg

[N. Thornton]

I'd check condition of mortar pointing. If its coming apart in places that will leave the wall much weaker, and much more prone to moving. Or it may be ground movement.

not very likely, though not entirely impossible if its been bodged badly enough.

Be aware that many Vics have original concrete floors in them, especially in the kitchen and pantry areas.

If theres a foot void down there, the conrete might possibly be just sitting on top of the original wood floor. Only reason to do that bodge is if the wood floor was rotten. If thats the situation, youre bound to have problems with it, possibly including floor collapse. All quite fixable though.

If you look round the exterior wall around the concreted area, see if there are any airbricks - note they might be inches below the soil surface. This will at least give us a fair idea of whats going on there. Using a wire to probe to see how deep the cavity is might or might not give useful info too. Then one can rule out some maybes.

NT

[Seri]

So it seems relatively doubtful that the cracks in the rear wall are caused by the exterior mass of concrete, although it's still a slim possibility. I should have said that this part of the house is an extension that was built with very little regard for best practices.

I can't really check the condition of the pointing as it has all been rendered over, is it worth chipping off some big sections of render to inspect it?

No airbricks visible what so ever, I've also poked down along the garden side of the concrete area and been unable to locate any, so I suspect that there's non here.

The interior floor of the extension is again concrete, but this seems to be completely sound with no cracks or dips.

One, potentially very very stupid question, how can I check to ensure that a lintel/load bearing beam was installed above the door-way in this wall?

Thanks again for the previous replies and for any further help.

Seri

[N. Thornton]

I didnt even know you had exterior concrete... with no pic...

then your pointings fine on that side. Check other side too.

none, or less likely rendered over. If no airbricks, probably concrete floor went in at new build.

only way is to smack shit off the wall till you see whats above the door. I wouldnt bother, unless theres a good reason to. Sometimes there was wood put in, sometimes a brick arch, sometimes nothing. In modern alterations steel support is the usual.

Regards, NT