Rendering dried too quickly

[Peter Watson]

I replaced some rendering on the side of the house over the weekend but
in spite of my best efforts to try and keep it damp it has already dried
out in this hot weather. It's quite hard so I am not too worried, but
my question is a general one - if a cement mixture dries out before it
has cured properly, when it gets damp again through rain or atmospheric
moisture, does the hardening process recommence or does it stay as is?

Peter

 

[Olav Marjasoo]

I replaced some rendering on the side of the house over the weekend but
in spite of my best efforts to try and keep it damp it has already dried
out in this hot weather. It's quite hard so I am not too worried, but
my question is a general one - if a cement mixture dries out before it
has cured properly,

You've used the correct word-CURED. To encourage a full cure in hot
weather, wet wall before starting, and wet regularly for next 2/3
days. An incomplete cure will mean less strength.
when it gets damp again through rain or atmospheric

moisture, does the hardening process recommence or does it stay as is?

I doubt it. The moisture would not penetrate far enough. But don't
worry it's probably OK. My field test is to score surface with a nail
after 4/5 days, if you make only a slight mark, the cure is finished.

 

[stuart noble]

You've used the correct word-CURED. To encourage a full cure in hot
weather, wet wall before starting, and wet regularly for next 2/3
days. An incomplete cure will mean less strength.

I think bonding agents like PVA have overcome these problems.