How long to wait between 2 coats

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PotatoSack

New Member
Hey guys,

Just got the scratch coat on today, 4:1 sand:cement + freeflo. How long should I wait before doing the top coat?

And should I keep the render wet for a few days to aid the curing process?
 
If you top the next day the waterproofer will not have set properly in the scratch coat leaving a weak skin on it.

The weight of the top coat can pull this skin off and leave the render hollow.

Try putting a scratch coat on and hacking a bit off the next day. The line of the waterproofer having not set is visible.

Leave a few days at least...just like everyone has said.
 
Generally 24hours is long enough for the curing process for the waterproof additive to work with a retardar if your using cementone freeflo or ever build I would use hydrated lime to stop any shrinkage cracks from happening. With freeflo you can always cover more areas as it holds back espesicially while using hydrated lime as well. Don't forget to lightly spray down the scratch coat with water to holdback slightly andto stop it drying out as quick.
 
How long to wait between 2 coats
 
Rich1981 said:
Generally 48 hours is long enough for the curing process for the waterproof admixture to work with a retardar if your using cementone freeflo or ever build I would use hydrated lime to stop any shrinkage cracks from happening. With freeflo you can always cover more areas as it holds back espesicially while using hydrated lime as well. Don't forget to lightly spray down the scratch coat with water to holdback slightly andto stop it drying out as quick.
Click to expand...

I was meant to say 48 hours.
 
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