Damp

[seanmcinnes]

I have an end of terrace property with a raised timber floor (to the orginal part of house), and a concrete floor to the rear extension (kitchen). The original house was probably built in the 40's at a guess. When I bought the house it was a condition of the mortgage I had 'damproofing' carried out so I did but as everyone knows its pretty much a waste of time. They probably injected water anyway so didn't expect much of it. Next I had a bunch call 4 seasons apply a flexible wall paint which was also meant to help prevent water from penetrating the bricks but I am not sure if that has had any effect.

The house has been and still is getting mouldy patches (shoe cupboard and under stairs cupboard).

My question is should I introduce more air bricks? It is a 9" wall. Should these be below the floor or above the floor or both (to get effective through venting to those cupboards?

I have looked at the schrijversystem but also seen very mixed comments about what they are doing. In effect are they not just adding a type of air brick?

Whilst only slightly tempted to resolve these issues I also found this, but am not sure if adding more holes is a good idea -
http://www.amazon.co.uk/Dryrod-Damp...=merchant-items&ie=UTF8&qid=1411678198&sr=1-2

Any advice or comments appreciated. If you have had damp proof treatments done that have worked please let me know.[/url]

 

[ree]

1. what did the mortgage dampproofers actually do? What is the name of the paint that was applied - any plastic paints will actually cause more damage.

2. The Dutch sytems are nonsense.

3. the dryzone business is also probably nonsense but its early days.

4. a 9" wall(gable?) indicates an older build than 1940's.

5. Then again, it might simply be condensation and have nothing to do with penetrating or rising damp? Airbricks venting directly into the cupboards might provide some relief.

6. often its best to simply remove any salt affected plaster and render up in sand and lime at 3:1.

7. Have you crawled your sub-area and examined the air bricks (clear) and joist tails (rot free)?

 

[seanmcinnes]

Thanks for the reply.

I don't have the name of the paint but it is something I will try and find.

They drilled holes probably at about 15cm centers and 'injected' a liquid damproofing which I assume contains silicon. To didnt have much faith that the job had been done properly but at the time it was more about satifying the mortgage requirements.

Unfortunately there is no access to the under floor area.

It is end of terrace with a hipped roof and the original construction is just 9" solid wall.

Do you have any opinion about adding external wall insulation. My worry if I do this is the wall will not be able to breathe but then maybe i will prevent the wall from penetrating water anyway?

If I am correct there is not a lot of plaster blowing off the wall of visible salts so I do wonder if it is 'rising damp' anyway.

The house does have tenants but condensation is not an issue although I do think ventilation could be better. My gut instinct tells me to add more airbricks to the subfloor area and one or 2 to cupboard areas to help get some air movement.

 

[ree]

Do you mean that you cannot find the underfloor access trap or that there is no crawl space below the floor joists?

Is the gable wall rendered?

There are positive claims for some modern systems of external insulation and render but i've no experience of them. Others on here claim to have installed them.

Perhaps, read up on here about condensation.