Dry Rot following renovation

[Spoondemon72]

Hi, purchased our home in 2021. Stone built farmhouse circa 1890 with external render (we are in South Wales). Property had been renovated to what appeared a high standard. Fast forward to now and I noticed a skirting board upstairs that has started to warp....weird..started to think may be a water leak/damp. Went away on holiday, can back and noticed fungi growing out from skirting board downstairs in the room directly beneath the one with the damaged skirting. Started to panic . Took moisture meter and it was off the scale in the skirting board near the downstairs skirting. Checked upstairs and damaged skirting was damp and also showed cuboidal damage. Cut a test hole into the upstairs plaster, turns out the renovation had installed stud walls with celotex behind with membrane directly against the original plaster on the stone wall. This has been done everywhere. Just starting to get people in to advise next steps. I know we have to stop the moisture which unless it is a hidden leaky pipe is looking like damp rising from downstairs?? Should I be getting rid of these stud walls where they have been installed on external walls and should I be worried that the dry rot has extended upstairs....all will be revealed in the next few days hopefully....thanks

 

[Spoondemon72]

Forgot to mention the test hole upstairs showed lots of fungus activity. We need to get the stud walls off to see the extent of the damage...

 

[Matt Green]

Just starting to get people in to advise next steps.

Careful. I would suggest an independent specialist- one that will not quote for works.

I know we have to stop the moisture which unless it is a hidden leaky pipe is looking like damp rising from downstairs??

Unlikely. Ground water has too much salt for dry rot- there will be a fresh water source somewhere.


M.

 

[CliffordPope]

Presumably the skirting has been installed against the face of the Celotex or its lining, so is therefore insulated from any contact with the stone wall itself?

 

[Spoondemon72]

Careful. I would suggest an independent specialist- one that will not quote for works.



Unlikely. Ground water has too much salt for dry rot- there will be a fresh water source somewhere.


M.

Thanks Matt, I am hoping we can discover an obvious issue, will check and post back.

 

[Spoondemon72]

Presumably the skirting has been installed against the face of the Celotex or its lining, so is therefore insulated from any contact with the stone wall itself?

So they installed the celotex with a membrane directly up against the old plaster inbetween the stud uprights which I believe is directly on the stone wall. They then put plasterboard over the lot and skirting board on the new plasterboard. What I believe to be the mycelium is very grey and in some cases I can take a piece and it will actually snap!

 

[Benanna]

Careful. I would suggest an independent specialist- one that will not quote for works.



Unlikely. Ground water has too much salt for dry rot- there will be a fresh water source somewhere.


M.

Hi Matt,
Would condensation build-up in the dry-lining cavity be enough fresh water to trigger dry rot?

Thanks

 

[Matt Green]

Hi Matt,
Would condensation build-up in the dry-lining cavity be enough fresh water to trigger dry rot?

Thanks

It would be one for the lecture slides, but yes, that's possible. Good call.

An expensive horror show for the OP to resolve, but at least not technically difficult.


M

 

[Benanna]

It would be one for the lecture slides, but yes, that's possible. Good call.

An expensive horror show for the OP to resolve, but at least not technically difficult.


M

How commonly does this happen?
We are currently mid renovation and have done a similar thing to some of our upstairs walls - small cavity, celotex between battens and plasterboard over top. House is solid stone/random rubble. Outside has been lime pointed but we couldn’t afford to lime plaster whole house so took this approach with upstairs rooms, including a wall between bedrooms containing a chimney breast. We did remove all existing gypsum plaster first, apart from on the internal chimney breast wall.

 

[Spoondemon72]

We have got an independent survey taking place on Friday, so I can ask the question, happy to share any views from that....

 

[Matt Green]

How commonly does this happen?

Not commonly at all.

 

[Spoondemon72]

It would be one for the lecture slides, but yes, that's possible. Good call.

An expensive horror show for the OP to resolve, but at least not technically difficult.


M

Hi Matt, when reinstating following the destructive stage and addressing the cause of moisture, should we avoid reinstating stud walls and insulation...I guess it comes down to whether condensation played it's part. If it did perhaps a different approach to finish the wall, avoiding stud walls, such as lime?

 

[Matt Green]

Lime would certainly be a better option than Celotex.