Waterproof cement drying time?

Cement “sets” by a chemical reaction not by drying out. Concrete for instance will set under water, it might not achieve the strongest bond but will set.

Thanks, yeah, I am aware of that but will it prevent moisture passing through, and how long should it take to cure?

IIUC, even when cured completely it's unlikely to be an effective 'tank'. It depends on the pressure behind the cement render, but overall, moisture will try to push through at the point of least resistance. That may (or may not) be the cement. I can't see an inch or so of anything being that effective in a cellar - moisture will push through at some point, either through the material or at a join.

I'm thinking of something similar in my own cellar along the lines of this sort of thing:

I'd give it a week or so, at a guess.

The ability of concrete to resist water is dependent on theamount of cement in the mix. water will not penetrate 100% cement or stone but will penetrate 100% sand.

The key is enough cement to fully fill the interstices between sand grains

That is why concrtete ships worls, and concrete swimming pools do not leak...

Months to fully cure, but for workably hard in spring 24 hours

Cheers. The reason I started this was because the thickness was less than an inch in a few places, so I replaced it with more, about 3 to 4 inches.

Thanks. The SBR container advised 4:1 sand to cement. I have been told this is "normal" for mortar in a brick wall, but now I am thinking that it might not be good enough for my use, even with the SBR.

Frustratingly, in another area, I mixed up 4:1 and added PVA from advice on a youtube video by a swiming pool repairer - I have since learned that SBR is preferred because once it dries it won't remoisten whereas PVA does, but the PVA mix has worked an absolute treat.

There's a few of them abandoned on a bit of the ship cannal near here.

Ah OK, good luck.

Depending on what you're after, I suspect proper tanking and a drain/pump might be on the cards. A mate has very neatly 'sealed' his cellar with a combination of a waterproof rendered floor and membrane on the walls. Looks good but the damp smell down there is overwhelming. It's not well ventilated, but even so . . .

Cheers. Yeah, it's a bit of a white elephant at the moment!

Sort of related, interesting programme on R4 at the moment on concrete. Adding oxblood good for waterproofing apparently, if you've any handy . . .

Ahhh, I don't believe it, I only chucked it out last week!