WFO built into retaining wall

[v12spirit]

Re: WFO built into retaining wall

I agree entirely. I also use the same product to make my entire supporting slabs waterproof to prevent moisture wicking up from the stand. I think you have the spelling incorrect though it is "Xypex"

Curious how the plans ignore this important simple step that can make a big difference , if this material was to used to waterproof the dome, where is it applied?

[david s]

Re: WFO built into retaining wall

There are a lot of different additives you can use to make concrete waterproof. Xypex does other things too, like enhancing strength. I think it is a better plan to use a standard render for the outer shell, then after around 10 firings the water should be entirely purged and the dome can be waterproofed. If you make the outer shell waterproof when it is first applied you are locking on moisture and therefore risk cracking the outer shell from steam expansion.

[Gulf]

Re: WFO built into retaining wall

..... If you make the outer shell waterproof when it is first applied you are locking on moisture and therefore risk cracking the outer shell from steam expansion.

Great advice! But, (if you do) add a vent to the apex of the dome through the final render .

[softy]

Re: WFO built into retaining wall

I should fire her up then before i do any more waterproofing
and hold back on backfilling to see if i get any cracks
thanks for the advice

Cheers

[deejayoh]

Re: WFO built into retaining wall

I agree entirely. I also use the same product to make my entire supporting slabs waterproof to prevent moisture wicking up from the stand. I think you have the spelling incorrect though it is "Xypex"

Yes, that's the stuff. I live in phonetic land. Anyway, to your other point - what holds water out also holds water in. So I don't think it would be good for a shell either. It's easier to use gravity to keep water off the dome. Just need a simple waterproof layer at the end. But for a hearth, it's great.

My $.02 on the reason this isn't in the plans is because it's not needed if you build an oven according to the plans. It only becomes necessary when you deviate.