DIY Doctor UK DIY Forums

Help. Penetrating damp from derelict neighbour!

hi, i have a problem with my property. my neighbouring terraced house is derelict, with a little amount of roof, lots of weeds and a whole load of water/ rain coming in. as you can guess i thus have a damp problem!
i can get into the house, as its been derelict for 15years. so i was thinking of spraying the party wall with a silicone based product to seal the water on the neighbours side.
or external render it?
any ideas, help or advice would be great.
tenants are moving out, new tenants have walked away, the council knows and has supposedly started the legal mumbo jumbo, but i cant wait anymore.
my house is getting very bad!
thanks mark
ps.would a thick black membrane work? how wouldi seal the top & sides from rain etc? would i have to treat the wall? wouldnt this method force all remaining damp back through my house but stop it in the long run?

Hi

Have you had a look at the DIY Projects section at all? There are a number of projects related to various damp issues: https://www.diydoctor.org.uk/projects.htm

Regards

Evening

My comments that follow assume that your property is a traditonal pre 1920's terrance house.

Without seeing photos or inspecting the property myself to see the defects and constructon arrangement, I can only really advise on what not to do. I would not recommend treating the walls. External walls should be able to function perfectly well without the need for coatings and a party wall is likely to be of similr construction. If you start to use coatings, you run the rik of trapping inherent moisture within the wall as well as preventing moisture ingress. This may lead to longer term problems.

In the first instance I would recommend removal of the weeds and providing temporary weatherings over the adjoinign owners roof to keep the rainwater away from the party wall so far as is possible.

Hope this helps

LCL

thanks,
the party wall, would have been intended for internal purposed, but now due to the neighbours roof having a hole in, it has become an external wall.
does this not make any difference?
thanks, mark

Mark

It does, but it also depends on the construciton of the wall. In my experience (as a Chartered Building Surveyor) far too much effort is put into damp proofing (ie covering over and hiding away the damp - the typcial "specialist" approach) rather than damp cure (sorting the problem once and for all).

As your issue clearly involves a neighbourin property, the cure may be not legally straight forward, even if constructionally it is.

I think it would be worth your time seeking the advice of a solicitor or citizens advice about entering the adjoining land to carry out repair works, but it sounds like the best method of cure would be to repair the adjoining ownrs roof, even if this only involves flet and batten to make it weather tight.

LCL