Cracks in garage.

[kyran]

Im currently buying a property that's has had previous subsidence, my level 3 survey has picked up cracks in garage which he says is likely ongoing subsidence. But im not so sure, as I think its more to do with the rsj... any help?

[Marvin]

Hi @kyran

 

It looks like the wall on the right hand side of the crack is dropping going away from the left hand side. Yes the RSJ on the pad stone is pushing down, but the foundations holding up the RSJ wall appear not to be capable of holding up the load.  Also it looks like the crack is where 2 different walls have met, presumably the foundations below each part of the wall are different.

 

You may also want to clarify how much this house insurance would cost.

Also what caused the previous subsidence. Was it a drain or roots or quality of the foundations or the soil.

You can pay a high insurance premium for a building that has had subsidence for 20 years!

 

Edited Sunday at 08:49 by Marvin
minor change.

[kyran]

I can currently get building insurance, for £50 a month but thats only if there is no ongoing subsidence! I want to get structual engineer involved but its the cost I may lose if I pull out of the transaction! The original cause was root induced clay shrinkage from the shrubs in the front garden!https://imgur.com/a/6TtnVgd these are all the photos I have of the garage, the cracks do not go to the floor and the different brickwork doesnt go to the slab either, which make me think it was a repair job in the past! 

[Marvin]

A rather poor drawing of what has happened so far and what could happen.. Note the gap at the top wider than at the bottom. Extreme drawing I know but you see how it falls and why the crack is bigger at the top and at this stage not visable at the bottom because it has not gone that far yet.

 

Edited Sunday at 10:36 by Marvin
clarification

[kyran]

I did originally think this but I sent photos to a strcutual enginer, and he said with subsidence the cracks dont fade away at the top!

[ProDave]

Unless this property is special or particularly cheap, I would look for a different one to buy.  Why take on such an unknown and possibly expensive risk unless it was cheap?

 

A bit more context where this garage is in relation to the rest of the house might help?  Is this the outer wall of an adjoined garage?  The wall between the garage and the rest of the house etc?  The joists suggest it might be an extension built above an existing attached garage and perhaps the foundations were inadequate etc.

[kyran]

This wall is attached to the house with no other cracks the other side, this is all part of the original house. The house is relatively cheap and we are now at the point of exchanging contracts! All that is above where the crack is, a balcony.

[saveasteading]

I'd need to see it in life, but that looks more like a rough extension or rebuild, due to seeing  the change in materials, and that cracks go through bricks not mortar.

 

My worry would be that in any future sale, a surveyor would flag it up.

 

 

 

[ProDave]

12 minutes ago, saveasteading said:

My worry would be that in any future sale, a surveyor would flag it up.

Get a plasterer to skim that wall and paint it.

 

If the cracks come back it is still moving.  If not, the poor joining of dissimilar materials is hidden.

 

Better still might be dot and dab plasterboard.  Less chance of the cracks showing through. 

 

If the cracks are not showing on the other side of the wall then it is either not moving any more, or it has been recently filled and painted to hide it.

[saveasteading]

11 minutes ago, ProDave said:

Better still might be dot and dab plasterboard

Agreed. And better yet, and easier diy, batten and board.

@kyran what does the other side look like?

 

BTW how wide is the crack at the widest point, excluding flaked away bits.

What is the widest coin that would push in? I suspect none, so no worries.

[kyran]

I was thinking move of helical bars and resin to just reinforce! I just can fit my house key in a couple of places! Also this is the other side of the rsj and the crack pretty much goes straight down, the old bricks are made of the old coal deposits, which are not very strong! Its a cavity wall im assuming by i would have thought there would be movement boths sides, the other side is the old woodchip wall paper. Theres no creasing or anything. Also on the external wall with the straight crack theres nothing in the render. Thats why I thinking its more to do with the load above causing the cracks

[saveasteading]

It has cracked some time ago, then been painted over. And stayed that way? 

If the key only fits in one place then that is not an overall crack of that width.

Plus if the materials change in each leaf the weakest will crack with any shrinkage or movement.

Helical bars would only move the stresses elsewhere.

 

The outside leaf may have stronger bricks than mortar, so have moved gently.