Render over dome (Australia)

[ChrisAdelaide]

Hi,

I have applied my 50mm of insulation blanket and a 100mm layer of Perlite and Cement (over chicken wire).
I am now looking at applying the final render. I am planning on painting the render afterwards.
Would a normal cement/lime/sand mix be appropriate? I notice Bunnings sell bags of Acrylic Render mix.
Does anyone have any recommendations as to what would be best?

Cheers

[david s]

If you look carefully at the bags of acrylic render you’ll notice that it is an “acrylic modified” cement render not a 100% acrylic render. The 100% acrylic render comes wet, in a bucket at over $100/10 litres. The PM render will also be partly waterproof and is resistant to water mixing into it, whereas a mix you make yourself won’r have this quality. A 4:1;1 mix of sand, hydrated lime and cement is pretty good. I use that mixed with the PM render 50/50 of each with plenty of AR fibreglass fibres randomly mixed for strength enhancement.

[ChrisAdelaide]

Thanks for the reply. So you make a batch of render using 4:1:1 sand/lime/cement and then mix an equal amount of the PM render? Do you mix it up dry and then add water or do you add water to each and mix separately then combine?

[david s]

That’s correct, I mix the two together dry including the fibres then add the water. There a lots of other solutions, but this is one that suits me.

[KISS4me]

Interested in how you go with this dome rendering with 4:1:1 sand/lime/cement and an equal amount of the PM render (whatever this is!). Hoping to get to my dome down here at Middelton later this month.
Steve