Mixing internal render

[Joet]

Would using half a bag of cement and 2 bags of sand give a correct 4:1 mix. Or should it be gauged in a bucket etc. Always done it this way but just wanted to check.

Also we all know 4:1 or 5:1 for internal but question is why? Some people say should be 3:1, would a stronger mix mean more cracks?[/url]

 

[roughcaster]

Measure it out, always the best way. You get a far more consistent mix doing it that way. Also, use "plastering sand".
When it comes to the mix itself, always make the top coat of render weaker than the scratch coat. If the scratch coat is 3 to 1, make the top coat 4 to 1,,, if the scratch is 4 to 1, then topcoat 5 to 1. Don't forget to use a waterproofer/plasticiser in the mix,, and use the manufacturers instructions on the recommended measured amount per batch,,, very important.