Rendered Dome Finish - Waterproofing

[fornoa]

Re: Rendered Dome Finish - Waterproofing

Thanks for that David.

[frank1985]

Re: Rendered Dome Finish - Waterproofing

If you add a waterproofing agent to the outer shell you risk locking in the moisture as well as keeping it out. This can result in the steam creating pressure in the insulating area and cracking the outer shell. I prefer to dry the whole thing out, about 10 decent firings, then add an acrylic elastomeric product, which can handle the expansion and also make it waterproof. you can paint over this in any acrylic exterior paint.

Is it necessary to use a masonry primer on the render before applying elastomeric paint?

[david s]

I’m not sure. I don’t, because I apply an acrylic product that does not require damp curing, but I can’t see that it would hurt, that area doesn’t get hot enough for it to be destroyed by heat.