Internal sand and cement render/undercoat

[marlb]

Hi,

I have built an internal wall across a room and want to tie it in with the wall on both sides. The original wall has a sand and cement undercoat and I want to do the same with the new wall. No problems plastering it but what ratio of sand cement should I mix for the undercoat (about 1 inch thick).

Any help appreciated

 

[stevethespreader]

4-1 scratchcoat and 5-1 floatcoat both with plasticiser

 

[marlb]

Many thanks

Will mix up in the morning...

 

[wittoner]

Whats a scratch coat and a float coat , do you still put a finish coat on ?

 

[smashngrab]

scratch coat is the first coat of render which you scratch up, these scratch marks give a key for when the top float (smooth coat) goes on. You may have seen rendering with lots of lines in it, this is the scratch coat.