Stain block

[marsaday]

How do you prevent a stain caused by water from coming back. I have treated the area with thompsons water paint which should stop the water / damp from coming through, but it seems to be coming through again.

This is on a plasterboarded chimney and there is no damp that i can see, so not sure why i am still having this problem

 

[HERTS P&D]

Faulty flashing around the chimney?

Andy

 

[marsaday]

Possibly. I will need to go and have a look

 

[emilybronte]

The answer to your original question is that unless you eradicate the cause of the damp, you cannot prevent the stain reappearing.

When the cause is remedied, then Zinsser Bin 123 is an effective sealant and stain blocker and it dries very quickly.[/b]

 

[vibrobullit407]

Zinsser Bin 123

BIN and 123 are two differing zinsser products. BIN is schelac based and 123 is water based. For a water stain I personally would not recommend 123. I would prefer to opt for a solvent or schelac based product (zinsser BIN or coverstain). But you may get away with using oil based undercoat to stop the stain bleeding through. As mentioned above though, the cause needs to be rectified prior to decoration!