Rrender mix.

[Robinkirby]

I wish to render the outside wall of my house. Can anyone tell me what the best sand/cement ratio mix I should use, both on first and second coat. And also what is the best sand I should use.

 

[chappers]

5:1 should be fine ask for plastering sand the builders merchants will know what you meen its a mixture of soft builders sand and fine sharp sand, some merchants sell it as mixed building sand.
Don't forget to add some plasticiser/retarder to the mix.

 

[Robinkirby]

Can you please tell me, is the scratch coat mix ratio the same as the top coat. It's just that I once heard someone say they have to be different to avoid cracking later.

 

[martinemj]

ratios for rendering (trust me ime a plasterer)

backing or scratch coat 4:1 (add a plasticiser to the water)

finishing coat 5:1 (add a waterproofer and plasticiser mix to water)



make sure you ask for plastering sand