How long for sand and cement screed to dry?

[Porthole]

Hi there

I'm having a sand and cement screed laid this week over 100 sq metres. Does anyone know how long it takes before you can walk on it? Builder thinks next day without boards. They plan to put large rooflights in next day involving 8 men so concerned about footfall on my newly laid screed. 

Many thanks

[markc]

You can walk carefully on it next day but moving heavy roof lights etc. Is likely to damage the surface. Lay some sheets of OSB or ply down to prevent heel marks etc.

[nod]

I wouldn’t go near it for several days this time of year 

 

[Russell griffiths]

cancel your fitters for a week at least, your asking for trouble, I couldn’t walk on mine for 3 days, then I covered it to stop damage, it was still green 4-5 days after laying. 

[Marvin]

1 hour ago, Russell griffiths said:

cancel your fitters for a week at least, your asking for trouble, I couldn’t walk on mine for 3 days, then I covered it to stop damage, it was still green 4-5 days after laying. 

+1. 

Is the screed on concrete or insulation? If on insulation then I wouldn't go near it for days. And how thick is it? 

[Dave Jones]

this time of year when its cold it will mark for 48hours if walked on. 3 days to be safe. This is sand cement with fibres screed laid to 75mm depth.

[Nickfromwales]

3 days minimum, unless you're happy to put 18mm plywood sheets down and police the activities. Even then this is not a great practice....

[DonkeyTable]

Are you using under floor heating Porthole?