Looking for advice from anyone who has used sika waterproof coating https://www.screwfix.com/p/sika-wat...1iWBWfOQ8jPSALo8E60nT7UBr_qEl3msaAv7WEALw_wcB I have a concrete floor in the kitchen which looks to have a failed DPC. When I removed the tiles (2 layers!) the concrete was very damp and it has never dried in 4 months. I’ve ‘painted’ 2 coats as instructed but after nearly a week there are still dark patches. Is the coating still in the process of drying out (I assumed it was waterproof once set?) or is it just the result of being in contact with a damp surface when applied? (First picture is before)
If it had worked, it would be dry by now. Can you check the manufactured date as the reviews for the product say it must be used within 6 months of this and some were sold beyond this date so the stuff was useless!
I was careful to check that after reading the reviews, it was all in date. I’m considering buying another tub and doing another coat just in case it’s due to a thin patch. That area was the worst part where I think the slab DPC failed.
I'm just going by the reviews too Ad. It isn't expensive stuff, so giving it another go seems like the best bet unless someone recommends a better alternative. I always thought Sika was a good make though. Does the existing coat feel as though it's set ok? It's not powdery or anything?
Update for anyone whos still interested! despite the discolouration a 3rd coat did the job, when I poured a layer of self level over the top it dried out nicely. I contacted sika (ever build) in the mean time who expressed concern that the 2nd coat was applied 5hrs after the 1st, despite the data sheet actually recommending this. Not a great deal of help.
I’m always thinking of the person like me who’s researching and needs to know the end result! In retrospect I’m not sure the extra coat was necessary, the rep from everbuild couldn’t explain the discolouration but once the self level concrete was dry there certainly wasn’t any dampness coming up. I’m now into other problems but that’s another story....