waterproofing dome

[Tony DF 69]

hi all, i am at the final stages of my wfo, in that, the base and dome just need finishing touches to them. i would like to finish my dome (which will be exposed to the elements)with marble pieces glued to the outer skin of oven. I put on a single coat of render so far (about 1/2 to 3/4 inch thick) which was made up of 6:1:1 white washed sand : cement: lime and a little bond crete with fibreglass strands spread through over dome. I was going to put another render layer over but i have read it is mainly for getting the desired shape , which i already have, and then glue on marble pieces. My question is do i need another render layer,how do i get the oven waterproof and will that be ok when i go to stick on my marble pieces with tile adhesive?
cheers,
Tony




I can nearly see the light!

[brickie in oz]

Re: waterproofing dome

Is that fibreglass insulation in pic two?

It hardly works as an insulator compared to ceramic fibre.

[david s]

Re: waterproofing dome

I used it for my first oven and found it worked ok but it is way less dense than ceramic fibre blanket and tends to compress which reduces it's efficiency.
To answer your Q.
I would try making the outer shell waterproof before glueing on the marble.

[Tony DF 69]

Re: waterproofing dome

Hi brickie , and David, thanks for replies, the silver blanket is only over front arch as a skin between bricks and render to try to stop any cracking.I used solid reds for dome and covered it with 30 mm ceramic blanket, chicken wire and then, about 30-40 mm 10:1, vermiculite: cement. Once it was completely dry I applied the render with fiberglass Strands troweled in at the end. I'm tempted to leave the render as is if anyone reckons it'll stop the rain seeping in. I rang around today, to see if I could use a sealer over render, but they couldn't guarantee my marble would be ok to glue over the top. Has anyone used a sealer and then glued over?
Thanks,
Tony.

[david s]

Re: waterproofing dome

If you use an acrylic waterproofer then use an outdoor acrylic tile adhesive the two should bond ok.I prefer an acrylic adhesive because I think it has more elasticity than a cement based adhesive. The temp for the acrylic is not an issue because the outer shell never gets too hot.

[Tony DF 69]

Re: waterproofing dome

Thanks David , sounds like you may have saved me from another coat of render!
Tony