We have an on going damp problem in our 500 year old, timber framed, grade 2 listed cottage.
The front room floor is about a foot below street level. We have french drains dug to improve drainage. On one wall they work on the other they don't. We have replastered inside and out is now traditional lime plaster which is "breathable".
Obviously there's no damp proof course and we would never get planning for one, I don't think it would help anyway. I think the damp is penetrating the wall rather than rising damp (it may be some of both). At it's worst point the damp is 150 cm high.
I would like to look into tanking, DH isn't keen. The damp is unsightly and horrible.
Any ideas/experience of similar? All input greatfully received.
Damp in timber framed buildings is a PITA. We have similar problems which seem to relate to one whole external wall (upstairs and downstairs rooms). We can see that the whole wall needs repointing as someone has helpfully filled all the gaps with cement in the past - which now needs chipping out and replacing as the cement doesn't allow the wall to "breathe". The biggest problems are where cement has been used to seal the join between the timber frame and brick infill. I'm not sure what French drains are but have you got enough room for air to circulate on the outside of the wall?
Whereabouts are you? I can recommend a couple of specialists if you're in the SE.
Have you spoken to SPAB about it? You can phone their advice line without being a member, and they do a 'virtual visit' via Google Streetview.
Given that the french drains on one wall are working and one isn't, is there something causing one wall to be particularly wet? Is there a gutter overflowing, or a downpipe discharging into the ground rather than into a drain? Is there a storm drain that keeps getting blocked?
SPAB correctly spotted that our downpipes just discharge into the french drain, hence a large amount of the persistent damp problems we've had.
A french drain is a trench that is dug to allow the air to circulate. It has helped, but not on this last wall!
Rockdoctor you have my sympathy - our whole place was covered in cement (both sides), we've spent a lot of money getting it all to breathable lime and still we battle on! Names of specialist would be appreciated we are Berks/Wilts border.
Grendelsmum - we are spab members so yes I will ring them. We went on their listed building owners course when we bought this place and have put everything we learnt into place. They may have a different perspective.
I am hoping that we don't have some burst drain or something leaking underneath. The highest point of the damp is in a place you wouldn't expect.
You could have your drains checked out - I did this (they pump water at high pressure in and see what happens) and it was a pretty quick and easy way to identify which drained into the ground and which drained into drains.
Our drain problems manifested in a pool of water about 5 metres away inside the house.
Thanks Grendels mum. We had a camera through the drains when we first moved here, so I know we don't have any drains near this wall. It's just if anyone else's drains are causing the problem. To find out we'll have to dig up the drive. It may come to that.
It's drying out a bit as it's warmed up and stopped raining but it's a slow process.