Garage wall potential collapse

Dick_here

Our house is up some steps, so the front garden is about two thirds of the way up the garage wall.  In recent months, the wall has warped inwards in the centre.  It's brick on the outside and breeze blocks inside the garage.  The breeze blocks are now visibly pushing inwards too with the cement and a block or two cracking.  This is getting worse now it has started.  I'm guessing the earth is pushing naturally in that direction causing it.  Big or small job potentially ?  Any thoughts appreciated !  See pics.

daveyjp

To fix it is quite a big job.  Demolish garage, dig out garden, build suitable retaining structure with drainage, or reprofile garden to a slope down to garage, build steps etc, new garage.

Dick_here

daveyjp said:

To fix it is quite a big job.  Demolish garage, dig out garden, build suitable retaining structure with drainage, or reprofile garden to a slope down to garage, build steps etc, new garage.

Eek.  What would be the cheaper approach if there is one ?  Any idea how much money we're talking here ?

Doozergirl

Do you have home insurance?  It might be covered.  

There isn't really a cheaper approach, it's an urgent job.  
 

Dick_here

Doozergirl said:

Do you have home insurance?  It might be covered.  

There isn't really a cheaper approach, it's an urgent job.  
 

The normal buildings insurance yes, hadn't considered that thanks.  Worth a call to them at least I guess.

weeg

I make my living as a structural engineer, so I don't say this flippantly. You have a problem and you need to get proper advice on this. It doesn't look in danger of immediate collapse or anything, but you shouldn't ignore this. And it's still moving, given the visible repair.

It looks as though the garden level has been raised by about 1 metre (how many stair is it?) and the soil has just been piled against the garage wall without any additional structure. As a ballpark, masonry retaining walls are about 600mm wide for every 1m retained height. which doesn't include anything beyond a cavity.  Looks like you have a cavity wall, so for the inner leaf to bulge like that the outer has moved at least 60mm. 

Find a local structural engineer. This week. Dig a hole adjacent to the wall outside, so you/ they can get an idea of what might be there.

Good luck. Let us know how you get on?

in_my_wellies

My neighbour found herself in an almost identical situation. She was about 75

As soon as she noticed she started digging. She just dug and dug until she created a gap all the way along, about the width of her body. Fortunately the weather was dry so new wet didn't add to the problem. It took her weeks! I helped with a few barrows when I could. 

Then she (we) hammered the breeze blocks back with a sledge hammer - Hoping the roof didn't give way. Looking back it was a bit of a risk. Did it very gradually, each brick a little at a time until they were quite tidy. Of course the outside bricks didn't push back and there is no cavity space.

Then she found a long piece of angle iron and we fixed this across the breeze blocks. On the outside she filled the gap with three or four layers of pallets placed vertically and covered them with plastic. 

It doesn't look pretty but it's holding up. I can imagine what would be written on a surveyors report but as she says it won't be her problem. Her daughter will live in the house when she is gone. 

I suspect the neighbours think we are both a little eccentric. (How I fixed my drive is another story!) 

Rosa_Damascena

in_my_wellies said:

My neighbour found herself in an almost identical situation. She was about 75

As soon as she noticed she started digging. She just dug and dug until she created a gap all the way along, about the width of her body. Fortunately the weather was dry so new wet didn't add to the problem. It took her weeks! I helped with a few barrows when I could. 

Then she (we) hammered the breeze blocks back with a sledge hammer - Hoping the roof didn't give way. Looking back it was a but of a risk. Did it very gradually, each brick a little at a time until they were quite tidy. Of course the outside bricks didn't push back and there is no cavity space.

Then she found a long piece of angle iron and we fixed this across the breeze blocks. On the outside she filled the gap with three or four layers of pallets placed vertically and covered them with plastic. 

Now that is gumption!

OP, this is going to need declaring to your home insurance company at renewal if not before.

Doozergirl

Reminds me of when a neighbour 'preventatively' underpinned his house to the tune of about 30cm using gravel, litter and postcrete.  

Bendy_House

A cheap way of sorting this?

First dig away the ground until you have a ~45o slope on that raised bank, and at least a foot of space at the bottom between it and the garage. If that is nicely compacted ground, then it should be pretty stable and take years to move. Add ground cover plants to help bind it. If it moves after a few years, dig some more...

Then do a 'wellies' as described above

Once the inside wall is hopefully pretty much back in shape, grind the exterior pointing to a near-half depth, and render the whole wall in stages to get it level - that'll add a good extra inch or two of mortar to the concave parts.

Yes, you'll have lost part of the cavity, but it won't fall down, and it should be dry.

If the inside looks ropey, render it too.

And don't forget a crash-hat. After all, Kamikaze pilots wore them.

Section62

in_my_wellies said:

Looking back it was a but of a risk.

It was a massive risk, nobody should attempt this kind of DIY repair themselves.

Before getting to the very significant dangers of attempting to alter a weakened structure whilst being inside it, digging a 'body'-size hole in unstable ground between that unstable soil and an unstable wall risked either (or both) collapsing and burying her under tonnes of material.

It took her "weeks" to dig the hole.  How long would it have taken for the emergency services to dig away material collapsed on top of her?  How many minutes did she have before the weight of that material asphyxiated her?

People who deal with this kind of problem on a professional basis have training on the risks involved and in safe methods of working.  It absolutely isn't something that other people should attempt to do based on your neighbour's experience.  They were incredibly lucky not to be killed... "a little eccentric" doesn't come close to the correct description of what they did.

Here are just two of many examples of what can happen when you don't give trenches and walls the respect they deserve -

https://www.bbc.co.uk/news/uk-england-suffolk-26194718

https://www.shponline.co.uk/in-court/building-firm-fined-over-lone-workers-trench-death/