Foundation wall crumbling, how bad is it?

[Matt723]

Hi There,

120y cellar is crumbling quite severely. It seems to have been patched already and most of it sounds hollow. I can take out large pieces, it's crumbling sometimes over 2 inches in.

I believe it is an old concrete foundation wall. I am unsure how much is the actual foundation falling and how much is layers or parging.

How bad is the situation and what would you do? Tempted to remove all that is crumbling and redo with chicken wire and either lime or cement concrete, but does this need more than that?

Than you

 

[noseall]

Hi There,

120y cellar is crumbling quite severely. It seems to have been patched already and most of it sounds hollow. I can take out large pieces, it's crumbling sometimes over 2 inches in.

I believe it is an old concrete foundation wall. I am unsure how much is the actual foundation falling and how much is layers or parging.

How bad is the situation and what would you do? Tempted to remove all that is crumbling and redo with chicken wire and either lime or cement concrete, but does this need more than that?

Than you

Is the cellar original, or was it retrospectively added?

 

[Matt723]

I believe it is original, neighbours have the same. There are also hold electric cables in there and old wooden Rawl plugs. All points to it being original.

 

[Matt723]

I removed dust and crumbling bits with my fingers, a brush and dustpan and big chunks just crumbled.

This is how it looks. I don't know if this is the actual fondation wall or some parging that is added to a brick wall behind?

By the look of it, and the presence of decomposing old steel bars in it (which I assume could have been "rebar" for the foundation to old onto) I think it might actually be the foundation wall itself?

Unrelated, but I also found some coal..

Any advice much appreciated.

 

[Ivor Windybottom]

Weird, is it trench fill that's been later dug out then rendered?

 

[Matt723]

What do you mean Ivor? To be clear the old coal was found in the cellar, not in the wall itself

 

[Ivor Windybottom]

I mean was a trench dug in the soil, concrete poured in then the house built up from there, with the bricks starting just below ground level.

Then later on someone decided they wanted a cellar so dug out the soil alongside the concrete.

It may have been for extra storage space or possibly damp-proofing.

The part on the left that's not been rendered looks like it may be the cast of what was a trench dug in the soil.

The best guess I can come up with, based on some photos on a computer!

In which case, if all that's falling off is the render that was put on later then it's probably not an issue. It won't be stuck very well because the structural concrete will have been muddy after it was dug out.

 

[Ivor Windybottom]

Alternatively, the bricks may have been originally just sitting on the ground, and the concrete has been added under it later, i.e. underpinning.

Unlikely though, they look undisturbed.

 

[Matt723]

Thanks for your reply. Basically the part that is on the left used to be like the part on the right, however the "render" is now falling in very large chunks. I am pretty sure it is only a matter of time before this happens to the rest of the length of the wall because it sounds hollow there too.

What you are saying make sense however there is a coal chute that looks original hence the cellar is likely to have existed since the house was first built.

What puzzles me is that the inside of the wall is still very soft in places despite those deep chunks that have come off.

I was hoping someone would have seen such wall / material before but I am not in luck so far.

Starting to wonder if it is time to bite the bullet and call a structural engineer in.

 

[Ivor Windybottom]

It may be that it was built as I described, but from the start. i.e. it was a bit of a botchy way of building a cellar instead of digging a big hole down to cellar level while retaining the soil, building up then back-filling.

That rough concrete on the left of the photo looks exactly like trench-fill concrete that's been dug out later. Tidy up with render, there's your cellar.

 

[cdbe]

Just repair it with mortar and consider it an ongoing annual maintenance task. It's clearly capable of doing it's job subject to it not falling out of the wall. For a more permanent solution you could build a blockwork wall around it and "backfill" with a mortar "slurry".