waterproofer for existing plaster and between wall copings

[martyc]

Hi want to apply some form of waterproofer to a wall that is already rendered.
Also want to do same to a block wall that is capped (between the cappings the mortar is allowing water into the wall.
Anyone recommend a product?
Cheers,
Marty.

 

[noseall]

thompsons water seal.

what makes you think the mortar between the copings is failing, would it not be better to re-point?

 

[martyc]

Hi noseall...

I have a dampspot inside the wall high up and the most likely cause (i think) is the mortar between the wall caps is letting a drop of water in.

There is a dpc under the caps and if water was getting to the dpc and ran off it towards the inside wall it could be causing my dampspot.

Its not a straightforward wall...its a twin leaf wall and the cavity is closed with a large block on its side, wallplate on top of the inside wall..then gutter then ~12" of a parapet wall.(with the caps i mention)
all the flashings are spot on and the gutter i put in is one piece and really cant be leaking so i think water is getting in between the caps down thru the wal and across the block that closes the cavity...and in!!
Cheers,
Marty.