The Natural Philosopher coughed up some electrons that declared:

NT wrote:
On Jul 28, 9:03 pm, Tim S wrote:
Rob G wibbled:

On 28 July, 02:10, John Rumm wrote:
Given this is a sub floor I can't see it being a problem. Very little
point pressure will be placed on it through the celotex. You will also
find it gains in strength with time.
snip

Tim
My recent concrete laying exercises have 'always' tended to end up
with such a problem. In fact the workshop floor was laid from the end
of a batch on a concrete lorry (conveniently shot through the hedge
from the roadside) but it was a pretty wet batch and that, with the
slight drizzle that started as we levelled it, meant that there was
'loose' water on the surface once it was level and covered.
That was about a year ago and it set perfectly hard - maybe a little
loose dust but the surface is OK and is not showing any signs of
breaking up with machinery on it.
Rob
Thanks John and Rob: I'll watch it and see what happens. Either way it
stays put but it will be interesting to see if it hardens up some more.

Cheers

Tim

Cement mixes take a few days to begin to toughen up. If its been a
while already, you can always pour cement slurry or pva on.



PVA will if laid on thin and in sufficient volumes, turn almost pure
sand into a reasonable surface!


One for google: Did this and it worked nicely