WFO built into retaining wall

[softy]

Hi all, after years of thinking where to put my oven, 6 weeks ago I decided where to build it. for years weeds were successfully growing, then I decided to grow some veges, then a week later out with the veges and in with the oven.
I am a bricky by trade and thought I would try to be a bit different with my fa?ade. it has been a challenge, it still isn't finished, need to insulate the dome and lay the capping, getting there slowly, still have a lot of landscaping to do as well. as soon as I work out how to post pics I will
cheers
Tom the bricky

[softy]

Re: WFO built into retaining wall

had a bit of rain in Sydney today but I still managed to get second layer of render over the dome. just need to water proof and do drainage then I can back fill the dome and continue on with the landscaping

[softy]

Re: WFO built into retaining wall

second layer of render on today with a bit of decoration

[david s]

Re: WFO built into retaining wall

One of the problems with a WFO is exposure to weather and the result being wet insulation. If you back fill around your oven with soil, drying the oven will become more difficult.

[deejayoh]

Re: WFO built into retaining wall

Your bricky craftstmanship is pretty evident in your dome. Nice work.

But I do have a question for you... what did you use for a hearth?
In this pic, it looks like the oven is built on top of pavers laid on the soil. Did you lay down a waterproofing layer?
And did you use any insulation under the oven floor?



As David points out, moisture is a real problem for these ovens. If you don't keep them bone dry and insulated, they won't perform well.

[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.

[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?

[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

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?

[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.

[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

[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

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

[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.

[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"