screeding a floor level from a 60mm fall

[zongatron]

Hi everyone,

I have a concrete floor downstairs that has a 60mm fall on it and I need to bring it to level.

Floor leveller would be VERY expensive as its about 40sqm and require multiple coats due to the depth.

I'm wondering what the best way would be to screed this level and with what mixes I could use?

Thanks.

Zonga

[havabeer69]

what are you putting on top once its level?


cant just use actual sand/cement screed for the bulk of it?

[ErrolFlynn]

sand/cement screed for the bulk of it... ...then put your floor leveler on top of that.

[r3nov8or]

Was the floor built with a 60mm fall, or is it due to some sort of subsidance which should be addressed first?

[zongatron]

The floor was built like that. Its been there for about 20 years.
I'm going to use it as a rumpus room so will be putting some hybrid vinyl floorboards on top.

Yeah ive never screeded a floor before so was wondering what the actual ratio and type of sand would be best and whether to drill in some short screws or dynabolts here and there to provide purchase or adhesion for the screed.

[havabeer69]

if its all internal, any reason you can cut some tapered joists, attach them to the concrete, ply ontop and lay your flooring on it?

similar to this


https://www.youtube.com/watch?v=t_bcaSJy8bs&t=408s

[zongatron]

Interesting idea.
I think it would make for a rough finish trying to merge the two materials. the slab is pretty level for the first half then suddenly tapers away about halfway to the edge.
So the tapered joists would only start at about the halfway point.
And then i'd need to merge the plywood and existing concrete.
Dont really like the sound of having half the floor concrete then half ply.
Thanks though, i an do that on the concrete verandah :) Instead of levelling the concrete out on the verandah I could do that and put a deck over it.