Self leveling floor for shed

[nads1978]

I have laid a floor in my new concrete shed - the base is about 6 months old.
The shed is 2mx3m
The base was pretty uneven, so advised by a chap in Jewsons, I made a sand (sharp) and cement mix (1 mixer full, 1.5 bags of Blue circle & water-proofer) to even out the low spots, this covered the entire surface, from 1mm to 10mm thick.

Then 2 days later, when the sand/cement was dry, I put down 2 bags of Bostik Cempolay self levelling compound, which can be 15mm thick. I mixed with a paddle in a large yellow plasterers bucket, 2 separate mixes and used a float(?) type trowel to aid the self levelling stuff to get all over the floor.

I definitely mixed it correctly.

There are a few patches where the floor is not completely cured. There are parts that are just compressed powder, which is dust like & comes away, when persuaded with a tool. If I brush over it, it isn't moved.

The patches on the floor do not correspond with any previous low/high spots.

What are my options?

Another bag of self levelling? (I still have a distance before the top of the step!)
Some kind of concrete sealer?
Both the above?
Another option?

The self levelled floor has been down about 2 weeks now.

Ultimately, I'd like to paint the surface for use as a workshop.

 

[nickjb]

Basic self levelling compound isn't suitable for painting and using as a finished floor. Typically you would put laminate or lino over it. The Cempolay Ultra Strong says you can use it as a finished floor, though. Which variety have you used?

Also your sub level of sand and cement doesn't sound ideal. You could get away with a bonded screed for that sort of thickness, you use an SBA and cement slurry mix to effectively glue the thin layer to the existing base. 1 to 10mm thick sounds way to thin for the mix you describe.

Not sure what you do now. I'd be tempted to put a little more leveller down to fill the gaps then put another surface over the top. Maybe a couple of sheets of plywood or OSB. Then hope for the best

 

[nads1978]

Thanks for the reply Nick, I did used SBA in the sand/cement mix, but only a small amount.
I just used the basic Cempolay self levelling compound, recommended to me by Jewsons.

I don't really want a floor other than painted concrete. I guess the Ultra Strong can be poured on top of the existing self levelling compound.
The floor will not be subjected to any heavy use.

Should I use a sealer or PVA before the Ultra Strong?