Structural repairs

[Silvia0723]

Hi

We recently bought a house where the a general movement report was provided for the cracking visible on the house.

The surveyors comments were that whilst there was a lot of cracking, he did not find evidence to suggest foundation movement or subsidence has occured in the past or is continuing.

He did recomment the cracks are strengthened by building in steel tie bars across the crack and reset the brickwork. I've seen the youtube helifix videos so this seems fairly straightforward.

He also recommended some tying of the wall on the rear flank wall to the internal first floor using a system of bow ties. (Dont know what this involves)

So my question is, is this something that your average builder can do? (some builders have suggested using wire mesh and wall straps?)

Or do you engage a proper structural repair firm?

Do you need to inform building control? We are also plannign to extend into the rear and side, and do a loft conversion at the same time.

Any help and guidance would be much appreciated!!

(sorry cant seem to get rid of the white bits on the pictures below so looks a bit messy)

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• Silvia0723
• 28 Nov 2011
• 1

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• Silvia0723
• 28 Nov 2011
• 1

Untitled

• Silvia0723
• 28 Nov 2011
• 1

Untitled

• Silvia0723
• 28 Nov 2011
• 1

 

[gibart]

Hi Silvia

'He also recommended some tying of the wall on the rear flank wall to the internal first floor using a system of bow ties. (Dont know what this involves) '

http://www.helifix.co.uk/products/remedial_products/bt.aspx


The bow tie method of restraining a wall involves drilling holes through the wall and screwing steel rods to the floor structure. The holes drilled are then grouted up with epoxy resin to hold the wall and floor together thus restraining the wall from horizontal movement. A better explanation can be found at the web adress above.

'So my question is, is this something that your average builder can do?'

Any competent builder should be able to carry out this repair and the crack stitching repairs. If you're worried about it, as i can appreciate many people would be i could probably recommend a few contractors to approach for a price depending on whereabouts in London you are.

This would be the most effective method of repair and I wouldn't recommend the mesh and strap method.

Not wanting to be the bearer of bad news but looking at the photograph of the front bay, i'm not certain that just stitching the cracks to the bay would be an adequate solution as, if movement is ongoing, the bay will more than likely crack elsewhere. You really need to ascertain whether or not movement is ongoing to determine whether the foundations require strengthening.

Gibart

 

[Silvia0723]

Thanks Gibart.

Coincidentally just had a structural engineer in to spec out the repair works.

Any ideas on decent contractors who would work in SW London?

 

[joe-90]

I wouldn't get recommends off a poster with just one post. He's probably signed up just looking for work.

 

[gibart]

I wouldn't get recommends off a poster with just one post. He's probably signed up just looking for work.

Thanks for the warm reception to the forum Joe!! I was just trying to help as i've gleaned a lot of information from this forum in the past regarding non - structural topics.

Just for the record i'm not a building contractor in any case.

KR


Gibart

 

[tim00]

1. whats the chronology here, of reports and inspections ?
A. did you originally have some kind of mortgage/house buyers survey report? if so, what did it say?
B.did you then have "a general movement report" for "cracking visible on the house"? And this report found no "evidence to support foundation movement or subsidence ... in the past or is continuing" ( sic ).
C. report B. recommended stitching the cracks and further remedial work at the "rear flank wall."
2. a builder or builders then became involved and gave various opinions? What did they find and recommend?
3. Next a structural engineer was instructed and issued a report. What precisely did he/she say?

We can help but it would help us if you supplied full elevation pics, and detailed pics of the front and rear elevations and the gable - with bins and obstructions removed. Also more pics of the interior where damage is present.

Is there a cellar? Does any neighbour have, or had, similar problems? Does the ground slope away behind the property? Have foundation test pit(s) been dug?

 

[Deluks]

We are also plannign to extend into the rear and side, and do a loft conversion at the same time.

Why didn't you just buy a house of the correct size in the first place?

 

[Silvia0723]

Hi tim00

We had the structural engineer round, and he seems to think a few steel ties either side across the cracks + rebuilding of broken bricks should do.

Now just in the process of finding a local builder with decent workmanship (and trustworthy - its taking us a while to find one!)

There is no cellar, neighbours seem ok, but havent had a foundation test pit (what's that?)

Engineer did reommend we test the drains near where some trees have been chopped down to make sure there has been no damage. Does anyone know how much a drains test would cost and if you just use any builder?

 

[^woody^]

I'm a bit wary of your engineers advice.

The crack must have been caused by something, and foundation movement is one possibility - in fact the most likely for the bay. And there must be some evidence as whether the cracking is old, recent or getting worse

So it is wrong to propose a solution (steel ties and rebuilding) without first diagnosing the cause and dealing with that. A sort of "PS - get the drains checked" is not really appropriate - the drains should be checked first

If there is a drain problem, causing the ground to soften and the foundation move, then once the drain is repaired it may well swell and so close the cracks back up. So that would be the time to do any repairs, not before

A drainage repair contractor should check the drains via a CCTV survey - about £150-£200. Then you, or the engineer review the report and decide if further work or investigation is required

The engineer should be able to recommend builders for the repair and drainage contractors for the survey who he has used previously

 

[Silvia0723]

Sorry I think I posted that badly.

The engineers report states the cracks are old and there is no evidence of subsidence, or that the movement is continuin.g

The report summarises that the cracks could have arisen over the years from weather, seasonal expansion etc

Its also believed that the property suffered from severe vibrations during WWII and hadnt received any maintenance in years.

On the drains, a builder who came round wanted £150 to test the drains with bungs (?) and about £450 for cctv..eeks!

 

[tim00]

1. test pits are small holes dug to the depth of the footings, and no deeper, to enable examination of the foundation and the ground below it.
2. trees, standing or removed, are reported accountable for the majority of foundation difficulties. Drains for about 10% of, usually more serious, difficulties. I figure your main drain is running to the rear, if so, it shouldn't be a significant factor.
3. the crack in the right c/breast recess is not historic, indications are visible of past repairs, and the crack carries on to presumably the return wall.
4.Imagine the front elevation without the bay and it is ,in effect, a mass of openings with thin panels of brickwork. Perhaps the rear elev. is roughly the same -so you now have the gable wall and chimney tied in with joists and internal return wall(s). There's also the possibility of a split chimney stack.
5. However, this is mostly speculation, without more precise info. it's difficult to advise you further.

 

[emyr46]

1. test pits are small holes dug to the depth of the footings, and no deeper, to enable examination of the foundation and the ground below it.
2. trees, standing or removed, are reported accountable for the majority of foundation difficulties. Drains for about 10% of, usually more serious, difficulties. I figure your main drain is running to the rear, if so, it shouldn't be a significant factor.
3. the crack in the right c/breast recess is not historic, indications are visible of past repairs, and the crack carries on to presumably the return wall.
4.Imagine the front elevation without the bay and it is ,in effect, a mass of openings with thin panels of brickwork. Perhaps the rear elev. is roughly the same -so you now have the gable wall and chimney tied in with joists and internal return wall(s). There's also the possibility of a split chimney stack.
5. However, this is mostly speculation, without more precise info. it's difficult to advise you further.

It is all speculation, as is the advice, you might as well ask the checkout operator in waitrose.

 

[tim00]

Dont feel too bad that your mum and dad were brother and sister -this forum could do with a village idiot.