re - rendering in hot weather

[jwpzx9r]

Hi I'm new to this forum so hello to all.
I have a house in south west France the kitchen wall which faces south is in terrible nick and needs re- rendering prior to tyrolean finishing. I was going to do the re - rendering when we visit in May. Now I have heard that cement mortar render should be allowed to cure slowly and since the rate of curing will no doubt be dictated to some degree by temperature, temperature at this time of year can be high 20's, is it advisable to do this job or should it be left until the autumn? Although it can still be hot then. Is there a trick to ensuring a slow curing rate? I will only be there for two weeks so anything that needs to be done can only be done then. Any advise on this matter would be most appreciated.

Many thanks

John

 

[JohnD]

If you do it in cloudy or drizzly weather, it should be slow enough. If you have to do it in hot sunny weather, do it in the afternoon when the sun is off it so it will have all night to cure. If you can dampen the wall first that will also help (but if too wet will reduce suction that holds the fresh render in place)

The next day you can mist it with a hose as it should be hard enough not to wash off.

All cement mixes are better if they are kept damp to cure. 24 hours is about the minimum for ordinary portland cement, it gains about 50% of ultimate maximum strength in the next 2 days, another 25% in the next 4 days, another 12% in the next 8 days and so on. You might also be able to cover it e.g. with polythene sheet to keep it from drying out.

Once it has got dry, it will not gain more strength even if you wet it again.

(the figures above are from memory)

 

[jwpzx9r]

Thanks for the advice I think I will persue a mix of all your suggestions depending on the weather at the time.

Cheers