Damp Proof Paint

[boustred]

Apologies if this should be in the painting decorating section!

I was thinking of painting around the base of my property (3-4 brick courses up) with some damp proofing paint to mitigate against water penetrating through the outer leaf.

I will be re pointing etc before hand and have done other works such as clearing cavities and adding air bricks.

The question is: What is the best thing to use? I have seen the clear stuff you can put on but then there is more thicker paint, of differing colours.

Finally - is it generally a recommend thing to do - any drawbacks? Is it worth doing in the combat against damp!?

 

[JohnD]

You can get a silicon liquid which you dilute with water and is supposed to stop water penetration.

You are right to renew the pointing and any damage first.

Paint which is non-permeable is likely to be pushed off the surface with water and efflorescence. Also it would prevent damp from evaporating off.

Some people like a rendered plinth to hide damaged brickwork but it must not bridge the DPC.

 

[Frederick]

If the damp is caused by rain penetration a silcone-based waterproofer may work. The advantage is that these are completely colourless so will not affect the look of the wall. The disadvantage is that they only prevent water penetration through pores in the mortar / brickwork, so if you have any cracks greater than 0.3mm it won't be 100% effective. In most case this means you need to repoint as there are often small cracks at the interface between the mortar and the bricks.