WFO built into retaining wall

[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.

[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

[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 .

[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.

[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

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"

[deejayoh]

Re: WFO built into retaining wall

To you actually deejayoh. The question is that does the concrete hearth suffice to prevent wicking up water? and how to waterproof the dome from the rain?

Concrete is not sufficient. It can wick water through several feet of thickness. Easily through a slab laid on grade. Without proper drainage you'll have problems. That's why there are so many wet basements in my part of the USA!

I added something called "Zypex" to my build - which closes up the capillaries in the concrete. They use it for swimming pools and sewage products. It was super expensive, but worth it in the long run

Softy - looks like you're on the right path, given Sydney's climate. But I might put some sort of french drain around the dome to be safe.

[softy]

Re: WFO built into retaining wall

the insulating fire bricks are not in contact with soil at all because after I done the dome I bolstered the IFB's and then I rendered over them as the base concrete was also about 100mm pass the dome if that makes sense

[david s]

Re: WFO built into retaining wall

That might work, but what about the soil that is in direct contact with your insulating firebricks? It appears that they are actually underground now. I'd be worrying that they are going to suck any moisture out of the soil as they are particularly porous.

[softy]

Re: WFO built into retaining wall

Hopefully the picture makes sense with how I am going about with drainage.
I realise I have only one drainage outlet and its only about 25 mm diameter but we don't get that much rain in Sydney but if it doesn't work I can always punch a bigger hole to drain water out.
cheers

[softy]

Re: WFO built into retaining wall

I layed a 200mm high strength concrete slab for the base. 50mm insulation brick and the pavers you see are fire bricks.
for the dome, I insulated with 3 layers of 25mm ceramic fibre and rendered with about 30 to 40mm of high strength concrete and again second layer of render about the same thickness concrete. now I am in the process of doing 3 coats of a waterproofing paint. you add 7 parts straight cement 5 parts water 1 part silasec and 1 part bondcrete. the last coat I will add black oxide.
for drainage I incorporated with concrete a dish which is also waterproofed and I will do all proper drainage so I can keep the dome as dry as possible.

[v12spirit]

Re: WFO built into retaining wall

To you actually deejayoh. The question is that does the concrete hearth suffice to prevent wicking up water? and how to waterproof the dome from the rain?

[deejayoh]

Re: WFO built into retaining wall

what is the material used for the waterproofing layer? I may be wrong, but it doesn't look to be discussed in the plans, does it?

not sure to whom you're addressing the question, but the plans call for the oven to be built on a concrete hearth that's protected from water. They don't really address other locations for an oven. But if you want to build on a retaining wall (which I also did) you do need to take extra care to ensure that water doesn't wick up through the hearth into the oven. Earth exposed to rain will collect water. A hot object on top of said earth will collect condensate. I added a waterproofing product to my concrete, along with putting down a 6mil plastic sheet, to prevent water from getting into the oven.

[v12spirit]

Re: WFO built into retaining wall

Did you lay down a waterproofing layer?

what is the material used for the waterproofing layer? I may be wrong, but it doesn't look to be discussed in the plans, does it?

[Novaslo]

Re: WFO built into retaining wall

First, i love your build.....it is really cool and will add so much to your home life.

What did you use for your render?
I will be soon finishing my dome and roof. I want to tile over the final coat of render but the stucco that I used the first time was very hard to work with.

I need to round out the dome a little better to make it more suitable for tile.