Rendering a Garage

nophd08

Hi All, As title says I need to plaster "render" my garage. What is best ratio of sand/cement to use, how many coats etc. I happened to see a plasterer today at work splashing on what looked like water on wall before first coat went on.
Do I need to use lime etc, any advice welcome.

Spread

Splatter (scud) coat of 2:1 sand:cement
Scratch coat:............ 3:1 " "
Float coat: ............... 4:1 " "

Mix some waterproofing in the scratch and floating coats ......... this will help to stop the suction as well as making it easier to rub up.

harry21

nophd08 wrote: »

I happened to see a plasterer today at work splashing on what looked like water on wall before first coat went on.

This is the norm.... its just to make sure the wall doesn't suck the water out of the render causing it to dry too quickly. Just spray a little water on the wall before the first coat as you say

nophd08 wrote: »

Do I need to use lime etc, any advice welcome.

No need for lime

Best of luck!

AckwelFoley

6 sand, 2 cement, 1 lime

Waterproofer mixed with the water if you wish.

If there is too high of difference in strength ratio of sand cement in the scratch coar and finish coat, you risk the possibility of the plaster cracking

Lime is essential, it makes the render stickier and binds the mix.

nophd08

Thanks lads, all good advice,
I have about 110ft long by 6ft high to do and the good thing is only a small portion will be in full view so a professional finish is not important, I will add waterproofer, small bit of damp getting through if its driving rain.

Al Capwned

Mix scudding @ 1:1 sand/cement
scratch coat @ 3:1
finish coat @ 10/2.5/1 sand/cement/lime.
I'd use w/proofer in scratchcoat and finish coat...
I'd also allow for an expansion bead every 3m.