I am going to cast a 2*2m2 slab, 10cm, in a newly built future boiler/technical room on which I will lay tiles (no waterproof membrane except for collar around floor drain, protruding pipes, etc.). I will cast it myself with a tombola and want to get the best quality in terms of drying time/wct in the bag, preferably pre-mixed as I want to be able to tile in at least a month. Which manufacturer(s) have low/lowest wct for pre-mixed regular concrete?
Thanks. I've looked into quick concrete and ROT, but it's still about half a cubic meter that needs to be poured, and it's quite stressful with ROT in those quantities using a regular mixer. I was thinking more about standard concrete, if there's any with < w/c ratio 0.40? Then it should be overlayable in 28 days according to calculations with a 10 cm layer, at least as I have read itnino said:
It's a crawl space with leca and gravel at the bottom, and then I fill it with 50 cm of compacted foam glass. After that, I want to pour concrete over it, so it's insulated but not moisture-sensitive or "sealed." As I said, I'm not going to apply a waterproof layer, just tiles.I have considered using Eps as well as a last resort. But at the same time, the foam glass already insulates equivalent to 20cm of polystyrene and 400l Eps would probably be expensive. Another reason for the slab is that I will at least have a tank in there, so at least maybe 700kg on an area less than 1m2 in one corner. But maybe it's okay with Eps as well since the underlying material can take quite a lot of load? I've never cast with Eps; if you reinforce it properly, how is the strength? Should you reinforce it again in the self-leveling layer perhaps?Peter2400 said:
If you're not going to have any waterproofing, you don't need to increase the concrete quality that much. You can lay tiles almost directly in a flexible adhesive. The biggest risk you have is shrinkage. The concrete will dry out anyway since you don't have any sealed layer, just more slowly.
Thanks. So if I cast with minimal water and use, for example, Weber coarse concrete from bags, which seems to be one of the better ones, it should maybe work. 4 weeks is probably no problem, I want it to have cured as much as possible as well, I have quite a lot of other things to fix in this project, but then I'd really like to finish and fix everything in the room. Anyone have a recommendation for a superb flexible adhesive?Matti_75 said:
Thank you for all the answers. EPS does not have much load-bearing capacity for a boiler room with very high point loads, so it will have to be regular concrete of better quality and minimal water during mixing, dry out for 1 month then tile with Ardex S48.
Then I'll have to give feedback.
It became a 10cm slab of Weber coarse concrete.
I made the slope directly in the concrete.
After about 6 weeks, I laid tiles with Ardex S48, a bit tricky/creamy tile adhesive if you're not used to it, but it turned out okay.
Now, nearly 4 months later, it looks just as good as when it was done.
It became a 10cm slab of Weber coarse concrete.
I made the slope directly in the concrete.
After about 6 weeks, I laid tiles with Ardex S48, a bit tricky/creamy tile adhesive if you're not used to it, but it turned out okay.
Now, nearly 4 months later, it looks just as good as when it was done.