Couldn't float new floor screed - mix ok ? - help please

[jonnyg1526]

Hi all,
I ordered 4t of readymixed floor screed from a company yesterday in order to raise my garage floor by circa 75mm.
The mix looked quite dry but the driver managed to make a ball and said it was ok. I laid the screed but I couldn't float it flat as it seemed too dry. I compacted and made as smooth as I could. The surface has dried but seems quite crumbly - couldn't get a flat floated finish. See picture. I'm worried now that the screed underneath will be crumbly also.
I'm aware it needs to dry and will take around 75 days to set fully.
Question is do I query the mix with the supplier? The driver took 2 samples and I have samples myself.
Even when dry I can't lay a carpet on it, I'd have to use self levelling on top.
I'm so disappointed as it went really well for a first attempt apart from the top finish.
Thanks for your help.

 

[r896neo]

It sounds like a big area to screed, did you have help and how long did it take?

Also what did you do to prepare the floor?

I wouldn't be concerned about the screed underneath, as long as it has enough cement and was mixed properly it will be fine.

 

[tomfe]

Hard to tell from the picture, but sand looks very sharp, what's all those big white bits in it?
Did you get your mix from a reputable company?
As long as you can make a smooth ball with it in your hand it would have floated up fine.
What did you use to float it?

 

[jonnyg1526]

Thanks for your help.
Yes I used a reputatable company and their rep is coming out on Monday to have a look which is comforting.
I think it was slightly too dry mix but I hope its sound underneth.

I ordered about a tonne too much in the end. It took 2 of us 2-3 hours. It's a floating screed with insulation (celtotex) below.

When it's dried fully I think I'll need to seal and use levelling compound to get a good finish.