Waterproof rendered finish on dome?

[RichC]

Guys, I'll be doing a rendered finish, white sand/cement and I live in a rainy climate. I need to do whatever it takes to make this waterproof without putting a roof on it. I currently have a well insulated vermicrete dome under a temporary roof. How can I go about ensuring the render doesn't allow water in? What type of membranes are suitable for this purpose or is there a better way?

Thanks

Richard

[Tscarborough]

Re: Waterproof rendered finish on dome?

If you have access to marble dust, you can replace some or most of the sand with it and it will waterproof it.

[david s]

Re: Waterproof rendered finish on dome?

A roof over the oven is best, but most expensive. The igloo is the cheapest, but will allow some weather entry. In between is the dog kennel in both cost and weatherproofing. Ireland is pretty wet, your choice.

[RichC]

Re: Waterproof rendered finish on dome?

Thanks guys! Tscarborough, dont think the marble dust is possible, I only seem to be able to source it in hobbyist quantities from art suppliers and it seems very expensive.
I cant tell my wife at this point that the beautiful dome is going to need a roof, she'll be gutted(and throw me out)
Has anyone on here considered the possiblility of building another form or dome of some sort over the insulated dome(with an airgap) and waterproofing that?? Maybe a wooden form... I dont know, just thinking! Not sure if such a thing would be possible? Any thoughts on that or has anyone on here tried such a thing?

[Greenman]

Re: Waterproof rendered finish on dome?

My dome has vermicrete over the CF insulation, then portland/lime/sand render over that and sealed it with an acrylic textured finish applied with a roller. It works and looks fine. Just need to make sure that water will not pool around the dome-base area. I eventually put a roof over the whole thing but it still gets plenty wet when the horizontal rain comes.

The pic has the details and the finish. Other pics are in the build pictures.

[RichC]

Re: Waterproof rendered finish on dome?

My dome has vermicrete over the CF insulation, then portland/lime/sand render over that and sealed it with an acrylic textured finish applied with a roller. It works and looks fine. Just need to make sure that water will not pool around the dome-base area. I eventually put a roof over the whole thing but it still gets plenty wet when the horizontal rain comes.

The pic has the details and the finish. Other pics are in the build pictures.

Thanks Greenman, that would definitely be the simplest solution for me if it works. I'm doing a concrete countertop first all round the dome that slopes downwards away from the dome so I dontexpect any pooling and the render on the dome will sit on the countertop to help water to naturally flow off

[david s]

Re: Waterproof rendered finish on dome?

To get marble dust go to a business that makes gravestones. That's where I get marble chips.

[ShuttleAU]

Re: Waterproof rendered finish on dome?

I used a two part epoxy waterproofing paint on my dome and stand. Keeps the water out. Painted over it with a texture finish

BC

[RichC]

Re: Waterproof rendered finish on dome?

Thanks guys, these ideas give me some hope that I'll keep the rain out without a roof.