I have a single skin/solid brick wall garage. It has a problem of penetrating damp due to the external ground level being 2 to 3ft above the damp proof course. Outside is flat ground with a patio on top, abutted to the wall.

The external ground is within my neighbours garden and due to the proximity to another garage and it's floor level being higher than mine it's not possible to excavate and simply leave, there would be an extreme slope to the ground. So it's also something my neighbour has not caused, but the builder of our houses long ago.

I have tried internally tanking, but that has failed.

I believe some sort of additional waterproof external skin or narrow trench would be needed, however a trench could fill with debris, and without regular access I cannot clear it.

Are there any tried and tested solutions available, perhaps some sort of enclosed but vented cavity, or barrier method that would be suitable for this situation?

I have seen paint on waterproofing for bricks, but I believe that to be more applicable to protect against driving rain situations


1 Answer 1


I'm insufficiently aware of what your common products are, where you are, to name any, but in a general way:

  • Excavation to the level of the DPC
  • Cleaning the exposed wall
  • Applied heavy waterproofing membrane (from DPC level to perhaps 10cm above finished grade)
  • Possibly also a drainage layer mat over that to a drain pipe running around to the lower side (or at least away, lower, somewhere;)
  • Then refill the trench.
  • Thanks very much for your answer. I'm based in the UK, but I'm not looking for specific product recommendations, but solutions, from there I can find a product
    – Mark W
    Nov 15, 2023 at 15:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.