Large crack, bowing wall
Discussion
Looking at buying a house that's going to need a fair bit of work. We've just had a survey, and mostly it's just 'tired old house' stuff, which is kind of obvious when you're buying a tired old house.
However, there's a nasty piece of news in that a wall in an extension that was added in 1922 has a large horizontal crack in it, and the whole wall from the first floor level is bowing outwards. The below explain it better than I could:
The recommendation is to get a cavity wall bloke to look at the wall with a borescope and a metal detector to see what there is in the way of brick ties in the wall. Then, either the wall will need retying or rebuilding from 1st floor up. The latter obvs v.expensive....
Anyone had any experience with this type of thing? Thoughts?
However, there's a nasty piece of news in that a wall in an extension that was added in 1922 has a large horizontal crack in it, and the whole wall from the first floor level is bowing outwards. The below explain it better than I could:
The recommendation is to get a cavity wall bloke to look at the wall with a borescope and a metal detector to see what there is in the way of brick ties in the wall. Then, either the wall will need retying or rebuilding from 1st floor up. The latter obvs v.expensive....
Anyone had any experience with this type of thing? Thoughts?
- Edited to sort pics out**
Yeah, it is hip all round, it's a house that's been bolted onto quite a bit. Main part is Georgian, then other odds and sods added later.
We're speaking to these guys to come and have a look:
http://www.petercox.com/in-your-area/london-and-so...
http://www.petercox.com/homeowners/wall-stabilisat...
Not going to be cheap. Sigh.
We're speaking to these guys to come and have a look:
http://www.petercox.com/in-your-area/london-and-so...
http://www.petercox.com/homeowners/wall-stabilisat...
Not going to be cheap. Sigh.
TimCrighton said:
Thats a very odd corner detail. I can't see how the outer is tied at all but it must be.
Would need to understand more about the construction and roof to think about why it might have moved.
Would strongly encourage you to engage an RICS building surveyor to review and spec out a solution before you cost anything.
Was a RICS building surveyor who gave us the heads up (and the photos). He's recommending we get a cavity wall man in: he can't see how the wall is constructed either. So this is why we've got the other guy on the go to be a bit more invasive.Would need to understand more about the construction and roof to think about why it might have moved.
Would strongly encourage you to engage an RICS building surveyor to review and spec out a solution before you cost anything.
The surveyor thinks it could be that the roof is loaded disproportionately on the outer skin of the wall, and this is why this is happening. I've not got the written report yet, but that's the story so far...
dingg said:
the ties expand when starting to corrode , usually happens when they used black ash mortar which encourages the corrosion of the steel , the thickening of the rusting steel pushes the bricks apart causing the horizontal cracking and the leaf of bricks 'grows' and causes the bowing.
on the picture I would expect to see the horizontal cracks at every 4th or 5th row of bricks if it was wall tie failure , there appears to be only one horizontal crack visible .
This is exactly what the surveyor said about the corrosion on ties, that it would be more than one crack (there is a thinner one up nearer the roof) but on the other hand, because he can't see inside the wall, he was unwilling to speculate (can't blame him).on the picture I would expect to see the horizontal cracks at every 4th or 5th row of bricks if it was wall tie failure , there appears to be only one horizontal crack visible .
dingg said:
Peter Cox will insert boroscope and say wall tie failure whatever the cause , it aint cheap to be done by them , get a local builder to do the work , if needed.
Very good point - if what you have is a hammer, lots of problems look like nails. dingg said:
structural engineer may say 'been like that donkey's years , old movement , just keep an eye on it , so thats the route I would take , survey by structural engineer , then remedial work by local builder - forget P Cox , they are not cheap.
OK, have contacted on by mail. Will chase up tomorrow during office hours. Good idea.dingg said:
wall tie failure is the new damp proof course required , semi scam IMO
Didn't know this.C Lee Farquar said:
If the suggestion is cavity wall failure then please get a brick removed so that a tie can be physically inspected. It's the corrosion within the mortar bed that matters, not the cavity.
As has been suggested it's very rare you'll get a clear report from someone with a borascope.
I used to do it for a living and genuine corrosion with expansion was rare, but needs sorting if they are the thicker fishtail ties. And yes it is the new DPC/radon.
OK, when I call the structural engineer, I'll ask about brick removal.As has been suggested it's very rare you'll get a clear report from someone with a borascope.
I used to do it for a living and genuine corrosion with expansion was rare, but needs sorting if they are the thicker fishtail ties. And yes it is the new DPC/radon.
Edited by EggsBenedict on Monday 8th September 21:54
TA14 said:
Don't get hung up about this wall tie issue. Even if you were to replace all of the wall ties you'd still be left with a distorted wall which would be weaker than the wall was originally and that may not have been strong enough. What you need is a structural engineer to look at the building and address the issues that I mentioned above.
Agreed - it's good advice and I'm taking it as per above.Small update. I've instructed a structural engineer to look at this problem. I've gained permission from the vendor that if there's work involved in making a proper assessment, then that's OK to go ahead so long as it's made good, so I've given the engineer the contact of a builder friend of mine who will remove a brick or two under the direction of the engineer, so that the inside of the wall can be looked at.
Not cheap, but at least I'll know.
Not cheap, but at least I'll know.
magooagain said:
While you have a man on site i would get him to take a couple of those hanging tiles off by that corner detail. It could uncover some better info than removing a brick.
It will also give an idea what's behind the tiles and a possible look into the cavity.
The engineer wants a couple of bricks removed on the large crack itself. With two bricks out, there should be sufficient room to work out how the wall was constructed as well as if there are tie issues, and also what the inner wall is made of. I've drawn his attention to the corner detail and the weirdness of it. He should be able to work out what's going on there, and also with the roof loading. He's seen the pics now - just waiting to hear when he's going to have a look at the house itself.It will also give an idea what's behind the tiles and a possible look into the cavity.
The brick tie people want 250+VAT to have a look, plus 1500+VAT to put the ties in, plus a structural engineer's report, plus scaffolding. So overall, if it's ties it needs, it'll be about 3.5K all in if we used those guys.
As we're using the structural engineer, it should be that we have a baseline on what work has to be done, so any quotes we get will be comparable.
As promised, here's an update:
a) I received the survey document from the RICS surveyor. His assessment hasn't changed between the conversation I had with him and the doc, other than he now thinks the outer skin of the wall should be rebuilt from the 1st floor up.
b) The structural engineer came today, and as above, I'd arranged for a builder friend of mine to accompany him. As it happened, I was able to spend an hour or so there with the pair of them. The outcomes are:
i) It's a very early cavity wall, 2 brick skins with a 2" gap between them.
ii) The part at the front where the brick meets the wall tiles is where the cavity wall meets a timber studwork type wall. The bricks are therefore side on to a substantial corner post. The bricks are not tied to that, so that's allowed the pronounced bow. A brick from the corner was removed to ascertain.
iii) A couple of other bricks were removed along the crack, based on the engineer using a metal detector to find ties. From this, it was ascertained that these brick ties have corroded, and this is causing the bow.
iv) It's likely that the engineer's report will advise that brick tie/wall stabilisation is going to be the remedial action.
v) A conversation with my builder, he thought that the wall could be rebuilt fairly simply and inexpensively once the scaffold was there.
All in all, it's not horrible, but it's certainly something that we'll need to talk more with the vendors about, as it's not the only thing that has been found, and although the other things are more straightforward, the cumulative expense in putting them right is punchy, even if we limit to just the things that the surveyor says require 'ACTION' instead of just 'RECOMMENDATION'.
a) I received the survey document from the RICS surveyor. His assessment hasn't changed between the conversation I had with him and the doc, other than he now thinks the outer skin of the wall should be rebuilt from the 1st floor up.
b) The structural engineer came today, and as above, I'd arranged for a builder friend of mine to accompany him. As it happened, I was able to spend an hour or so there with the pair of them. The outcomes are:
i) It's a very early cavity wall, 2 brick skins with a 2" gap between them.
ii) The part at the front where the brick meets the wall tiles is where the cavity wall meets a timber studwork type wall. The bricks are therefore side on to a substantial corner post. The bricks are not tied to that, so that's allowed the pronounced bow. A brick from the corner was removed to ascertain.
iii) A couple of other bricks were removed along the crack, based on the engineer using a metal detector to find ties. From this, it was ascertained that these brick ties have corroded, and this is causing the bow.
iv) It's likely that the engineer's report will advise that brick tie/wall stabilisation is going to be the remedial action.
v) A conversation with my builder, he thought that the wall could be rebuilt fairly simply and inexpensively once the scaffold was there.
All in all, it's not horrible, but it's certainly something that we'll need to talk more with the vendors about, as it's not the only thing that has been found, and although the other things are more straightforward, the cumulative expense in putting them right is punchy, even if we limit to just the things that the surveyor says require 'ACTION' instead of just 'RECOMMENDATION'.
Edited by EggsBenedict on Tuesday 16th September 15:23
TA14 said:
Good luck with the negotiation; try to remember that the remedial cost of this work won't be much in comparison with the purchase price and that any other vendor will/should go through the same process as you - hopefully the estate agent will stress the latter.
No, but the cost of remediation is a non-trivial percentage of the renovation budget, and we didn't go into the process thinking that there'd be chunky structural work to be done (again, bear in mind this wall issue not the only thing). I'm going to take a bit more advice on how to approach this.In terms of sale, I suppose (1) I'm not thinking of selling for a long time! (2) I have a dilemma in that if the structural engineer recommends remdial ties, and then I do something else, I don't have the 'audit trail' of strucutural engineer's report, and then certificate from a tie-ing company that shows them having followed what the engineer says.
Emailed the SE to make sure he includes rebuilding as an option. Once I've got his report that shows what needs to be done, I'll get quotes for both options. I think rebuilding sounds like the way forward. I would like to find out what the score is around the roof. What happens when the outer skin is off? What holds the roof up?
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