Using a damp proofing slurry. Damp can be a major issue in the home. Find answers to questions or post your own here.

[Arnak]

Hi,

I am planing to use a mix of SBR and cement to waterproof a damp wall.

What ratio of SBR to cement would you advise?

This is going to be applied to an existing cement render then plastered on top, will the plaster adhere to this slury successfully?

Unfortunately this is about the only option open to me as the house is old and built of random stone, so there is not much I can do about adding a dpc.

The wall is an internal one and as long as this method works for 5 years or more I'll be happy to re-do the whole job again then.

Thanks,

Arnak

[thedoctor]

The cement should be added to the SBR and continually stirred until its the consistancy of porridge. This is usually 1 part SBR to 5 parts cement. Its not a great idea to put it on top of render as, when a wall is damp, its usually the render that soaks the water up vertically. This means that there is a likelyhood of the render still being damp and this could well push the render off the wall together with your new coating. To be totally effective the new tanking should be applied to the original surface of the wall with the render taken off and any holes filled with a mkix of sharp sand and cement at 3 to 1.

[Arnak]

Hi Doctor,

Thanks for the advice it is really useful. :D

That should solve the problem, at least for now.

Arnak