Comment on Damp Proofing a Basement by Adding a Damp Proof Membrane (DPM) by Renovation Dave.

Why do you assume this was about saving money?

In time terms it was far more expensive than hiring a company to come out and inject a fresh chemical damp proof course, but we plan to live here for a long time and I want the job done the best way possible under the circumstances (best way would be knock the house down and start again :)).

As I see it if this fails my first course of action will be to add a plastic damp proof course on the outside bricks that cover 3 of the 4 sides of the property, (I might do this long term anyway as will add to the damp proofing) if having a plastic damp proof course on both sides with the new damp proof bricks isn’t better than getting a company to drill a hole every brick and inject a chemical in hoping it will form a water proof barrier I’d love to understand why?

I’ve read research that the injection damp proof course is far from a perfect solution to damp proofing and fails often, added to that the last attempt at a chemically injecting DPC failed (and failed badly!) in under 10 years I don’t have much confidence in that form of damp proofing!

I was concerned about the under-ground part of the house as that had a great deal of damp (wet to the touch) and also know the latex paint will fail eventually. So far it’s holding up well one year later, and taking into account the tanking like thing we did even if water does get through the latex paint (and it will eventually) it won’t get through the plastic DPC sheet between the wall and anything that could be damaged by water: unless you think the 1200 gauge DPC sheeting will rot quickly? I temporarily patched a hole in an old shed roof outside over a year ago and it’s still doing the job despite being in the sun and rain for over a year.

If what I’ve done generally lasts 25+ years and that one major problem area lasts 10+ years I’ll be very happy with the result.

The basement of the house has been transformed from unlivable to very comfortable. Could you imagine a builder as a matter of course adding several inches on insulation to all walls (and using 1200 gauge DPC sheeting just in case)? Insulation isn’t that expensive, (was around £15 a roll, the 1200 gauge DPC sheeting was ~£30 a roll) but when using it to coat walls as well as ceiling spaces (we’ve insulated every space we can) it adds up.

This was done for our comfort, wasn’t about saving energy in the winter to save money per se (all these types of improvements takes decades to pay off in fuel savings), was about having a house that didn’t have big drafts in winter and would be cool in summer.

It’s working so far, middle of summer and I have a lovely cool basement to live in (we haven’t bothered using fans this year not needed).

David Law