One Coat Damp Seal 250ml - Seals and Blocks Damp Stains - Permanently Cover Damp and Water Stains. - Fast Drying

Dries fast, and stinks while drying. Reminds me of the way paint used to be.Brilliant

I searched a few products that did this job, and found this one to be the most reasonably priced. It was easy to apply. I don't know if it works, as I only used it a short while ago, also not long enough to see if it stops the damp coming through yet really. But, I am confident. It dries fast too which is handy.

Did exactly what I needed it to do. Very strong fumes though so be careful if you have breathing difficulties etc. Didn't last too long with the window open though. I had some water damage that 3 coats of paint didn't cover, applied this, waited on it drying, applied another coat of paint and it's covered it perfectly. Would recommend.

Used a few different damp sealers in my time but found this one to out perform more expensive counterparts

Very good.