Tank or external barrier

[Scot22]

I have a first floor flat with a problem of penetrating damp. Everything has been checked, rainwater goods, pointing etc. Someone has suggested tanking the flat.
However, I would prefer not to have the upheaval. Would an external cost of sealant do the job as well ?

 

[KenGMac]

Scot22, good evening.

Any chance of some external images please?

is the penetrating damp manifesting as large spots of dampness, or as large patches of damp?

Are the walls retro- cavity filled?

Ken.

 

[Scot22]

Thanks Ken. Unfortunately not able to download pics. It is definitely straightforward penetrating damp. Wall is as original, nothing retro. Simple debate as to how to deal with it.

 

[Notch7]

I have a first floor flat with a problem of penetrating damp. Everything has been checked, rainwater goods, pointing etc. Someone has suggested tanking the flat.
However, I would prefer not to have the upheaval. Would an external cost of sealant do the job as well ?

It might work.
Is it a cavity wall construction or solid wall?

siloxane products are better than the off the shelf Thomsons water seal type

https://www.rawlinspaints.com/home/exterior-masonry-paints/317-rust-oleum-mathys-secco-super.html

https://www.promain.co.uk/mapei-antipluviol.html

 

[Scot22]

Thanks, very helpful. That seems to be just what I'm looking for. I have been advised that the wall needs to breathe.
Someone suggested replacing cement mortar pointing with lime mortar pointing. Could that stop penetrating damp ? Is it worth the expense ?

 

[Notch7]

Thanks, very helpful. That seems to be just what I'm looking for. I have been advised that the wall needs to breathe.
Someone suggested replacing cement mortar pointing with lime mortar pointing. Could that stop penetrating damp ? Is it worth the expense ?

I think waterproofers need to be applied when the brickwotk is really dry, you dont want to trap in moisture.

An external waterproofer will stop rain water from soaking in to the brickwork.

It all depends on whether thats the problem.

In term of pointing: if uou are treating with a waterproofer I cant see the gain in repointing. The waterproofer will make the pointing water resistant so it wont absorb rainwater.

Is the wall on the face that gets driving rain and all the wind -high wind pressure certainly makes porous brickwork soak up water.

If its a cavity wall, the damp should not be getting through anyway.

 

[Scot22]

Not a cavity wall. The suggestion was to only replace pointing and not bother with sealant. on the basis that lime pointing was originally usef. However, would that stop penetrating damp ?