Seal concrete block wall?

I'm fitting a mirror in my bathroom which, due to the lights built into it, is designed to be recessed into the wall. So, by Aldi Fein-alike and SDS, I'm cutting out a wide shallow space in the wall. Most of the depth is taken up by tile and plaster, but I am taking off a very thin layer of the hard concrete block that forms the wall itself.

Does the group think it's worth somehow sealing the face of the block? There shouldn't be any actual splashing water here, but it's a bathroom with a sometimes very humid atmosphere. Or am I worrying about nothing?

Cheers,

Pete

Reply to
Pete Verdon
Loading thread data ...

I think that would be wise. I would probably use bitumastic paint, but it might be subject to condensation. Perhaps a skim of plaster over the cut block, and several coats of emulsion paint?

Reply to
Bruce

PVA is not suitable, because the adhesive "re-activates" when wet. SBR is waterproof but too expensive by virtue of its 5L unit quantity.

Mapei Primer G is a good water resilent primer, priced at =A34 from Screwfix - basically not much more expensive than PVA. Mapei Primer S is a fully waterproof version, but you're not planning on a swimming pool I assume :-)

If you can, consider getting a quiet humidistat controlled fan in the bathroom. Whilst some condensation will still occur since it can't keep pace, it will reduce it somewhat.

The lights incidentally will provide some heating which may mitigate condensation (just a thought).

Reply to
js.b1

Ah ha! I actually have a few bottles of that in the shed left over from the tiling. Of course, I've installed the mirror frame in the cavity now so it won't be quite as easy to apply, but if the consensus is that I need something that's probably what I'll use.

Yep - got one, but not wired up yet. (Actually, it's not humidistat controlled, it's on an overrun timer off a flow switch in the shower supply, but same idea.) Hopefully once that's in action there'll be less condensation about.

Indeed, the lights (fluorescent tubes, so presumably not *hot*) are supposed to be warm enough to stop the mirror fogging.

Pete

Reply to
Pete Verdon

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.