Cracks in internal walls

[scaredofcob]

I wonder if you can advise.

One wall (cob) has serious looking cracks ( and hole) and they have considerably extended over the last few months.

The property has been owned by the same person 40 odd years and Ive never seen anything like it.

Could it be serious? Who would I start to contact to investigate?

Insurance company?

I am worried. I am relieved that there doesn't appear anything on the outside.

 

[Penners]

Can you explain the problem in a bit more detail?

Are you saying that the cob walls are cracked, and have at least one hole in them internally, but that none of these problems is visible on the external rendering?

How old is the house? Are the affected walls structural? Do you have any idea what has caused the cracks/hole to increase in size? Are rain and/or damp getting in?

If possible, a few pictures would help people to try and diagnose the problem.

 

[Gervase]

Any crack that enlarges over a matter of months is a serious cause for concern.
You need to get a surveyor in to inspect the wall - but not any old surveyor, as most will not know much about earth buildings.
Look at the 'seeking specialists' topic on the menu to the left and find a surveyor near you. If you're stuck, contact the conservation officer at your local council, as s/he will know of surveyors who are experienced with traditional buildings.
Don't approach the insurance company until you have an expert opinion - if you talk to them first they will appoint a surveyor who will probably know nothing about cob buildings and who may recommend wholly inapropriate measures.
Good luck, and fingers crossed that it's just vermin or something minor!

 

[scaredofcob]

I will try and explain more.
It is an old property ( at least 1800) but not listed. I was hoping it was just cosmetic but I am worried from what you say.
It started with a hole 1m above ground level and then several cracks spread from it.
Could it be constituted as an insurance job if sinister?

Would the solution be very disruptive to an elderly occupant?

 

[Penners]

How big is the hole? Did its contents just suddenyl fall out on the floor one day? Or was it (as Gervase mentions) perhaps the result of rodent activity?

If the hole has appeared because of "normal wear and tear" then an insurance company won't help you. But if it's been caused by an insured event (e.g. subsidence) then you may be able to claim.

 

[scaredofcob]

It's not a hole as such; just the way the wall has given way towards the room so that you can see the space behind. Nothing has fallen out; just hanging precariously.

The cracks leading away are numerous and very long ( vertically upwards and horzontalish but not below). New internal wall?

There was a flood in that room 9 years ago. Could that be the problem? Why take 8 years to see the effect though and why would the starting point be 1m above ground level?

I have noticed a small crack on the outside now but nowhere near the initial "hole". It's not my property so don't know what came first.
The wall is close to a road but there is another wall closer and that is intact.

 

[MdB]

Sounds to me you need to get an expert in to take a look at it. Nobody will be able to diagnose from your description. Photos would help but it doesn't sound minor to me.

 

[Penners]

Sounds to me you need to get an expert in to take a look at it.

I agree. And of course Gervase's comment should be taken particular note of - no rapidly enlarging crack should be taken lightly.

I suppose a flood 8 years ago could be the root cause, and might have started a problem that has taken 8 years to finally become visible. But you need expert advice - that's certain.

I should start looking for a structural engineer who is well experienced at this type of property.

Unless you know of one locally, a good place to start might be here.

 

[BMcD]

As has already been mentioned, an expert structural engineer who is conversant in cob should be sought But (and not wishing to be a doom monger) what concerns me is that you say there was a flood 9 yrs. ago and that now the problem is evident 1m high. Has the building been damp proofed following the flood? If so this could cause moisture to build up in the bottom metre of the wall, due to the damp proofing plaster, perhaps causing the cob to slump. However I must stress that I am not an expert in cob buildings or indeed damp. And as mentioned previously it is very difficult to diagnose remotely so do find an expert and they will advise accordingly.

 

[MdB]

Good point BMcD.

Is the cob built on a stub wall? How does moisture get out of the wall? Has it be covered with cement trapping moisture inside the wall? A number of people have talked about cob walls collapsing in the past after they have been covered in cement. It is a good way to make them fail.

 

[scaredofcob]

I'm afraid I cannot answer the previous questions. I have absolutely no experience of any buildings let alone cob.
I had hoped for the sake of the elderly occupant this could be ignored but it obviously can't. I am now concerned with the outside having taken another look. How can I temporarily weatherproof from rain? Sheeting?
The flood repair ( to floor only, I think) was an insurance job but unfortunately a different company to now.

Are we talking a LOT of money?

In my panic, I have forgotten to thank everyone for their input.

 

[Gervase]

You could be talking about change from a tenner or thousands - it's one of those cases that's almost impossible to diagnose without seeing the place. You really do need to get someone conversant with cob to look at it. Whereabouts is the place?

 

[Penners]

How can I temporarily weatherproof from rain? Sheeting?

If you suspect that there are entry routes for rainwater into the outside of the cob wall, then you should certainly try to stop this as quickly as possible.

You could, as you say, cover the entry routes temporarily with waterproof sheeting, but make sure that the sheeting doesn't prevent air circulation against the wall.