Damp in External Wall Damp can be a major issue in the home. Find answers to questions or post your own here.

[Scimitarf1]

We live in a Victorian (1896) house with cavity walls. The damp proof course is not particularly evident and is apparently a bitumen layer (I have not been able to ascertain this despite trying).

There was a dodgy french drain that was filled by our builder that was cleared, filled up slightly and a channel put in (higher than the original floor of the french drain). Now there appears to be damp rising on the outside wall as evidenced by moss and green stuff appearing on the wall. What can be done to reinstate the integrity of the DPC? Should I go for injection of silicone?

On the other side of the house there is an intermittent render at the bottom of the wall (similar to that seen on terraced houses on the street side). This was disturbed when doors etc were shunted around. How can we make this continuous again? How deep does it need to go?

Will

[stoneyboy]

Scimitarf1,
You do not have cavity walls but you probably have a slate DPC.
You can either lower the level of the channel or have a silicone DPC injected.
The rendering at low level on the wall is to reduce splash back getting onto the porous wall - just make good where it is missing and apply masonry paint to seal it.
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