S.E. Quensland Suppliers.

[avago]

I have started building my wood fired oven last week. So far got the concrete slab down, the walls up and just finished boxing the walls for my second pour of structural concrete.
So far I have used local landscape suppliers for the besser block and sand and cement.

I have found a vermiculite wholesaler in Carole Park who does cash deals ($25 per 100 litre bag).

Been unable to find anyone doing heat blankets local though.
Anyone any ideas?
Would love to hear from you.

[BackyardPermaculture]

Re: S.E. Quensland Suppliers.

Yep - give these guys a call, they sell a product called "Rockwool" which is a blanket which works really well and is a great price. I bought a bag with two rolls, since we were making two ovens - not sure if you can get a single roll:
Total Insulation, Brisbane & Perth Australia - Suppliers of Rockwool, Polyurethane, Industrial and Commercial Insulation including Pipe & Boiler Lagging
They're also fairly negotiable on pricing.

Cheers,
Mick

[avago]

Re: S.E. Quensland Suppliers.

Thanks Mick,

got my concrete for my hearth poured today.
Things are starting to get exciting. My three kids ask every day after school if the oven is ready yet. Think they are more excited than me.

Wish we had more brick suppliers in Brisbane. $3.00 a pop soon adds up.

[nissanneill]

Re: S.E. Quensland Suppliers.

Hi avago,
try

Thermal Ceramics
1800 467 858
416 Bradman St
Acacia Ridge QLD 4110

Their head office is here in Adelaide but factories all around the world and have all that is needed. Their superwool is great and have vermiculite and fireclay.

Cheers.

Neill

[BackyardPermaculture]

Re: S.E. Quensland Suppliers.

Hi avago,

The brick price is definitely high; one of the reasons I went with a clay dome.

All the best with the build
Mick

[avago]

Re: S.E. Quensland Suppliers.

Thanks Gents,

thought I posted a reply but when I came back to this forum it did not seem to have been posted up.

[avago]

Re: S.E. Quensland Suppliers.

Checked my second pour today. All seeems good.
Will leave covered to cure till Sunday.

After reading the guru Alan Scott and watching one of his classes, I decided to change my design. He pours vermiculite and then covers it with concrete. On this he mounts his fire brick floor. This means the heat goes through the fire bricks and heats up the concrete (which would cause it to expand and crack). I have decided to pour concrete first and leave a square in the middle free to pour vermiculite into. I will then lay my fire bricks on top of this. I know the vermiculite will expand when hot but it sits atop the concrete so should be fine. As my firebricks are only sitting on a bed of fireclay and sand i see no problem with the floor expanding when hot.
Who knows? Perhaps I made a huge boo boo. Time will tell.

[nissanneill]

Re: S.E. Quensland Suppliers.

Just make sure that the thickness of the vermiculite cement is sufficient to meet your needs, ie. a thickness of 3" would be minimum I would think. An insulating board on top of the cement would not go astray as it would then provide a nice flat surface for your hearth bed but comes at a cost.
Cheers.

Neill

[avago]

Re: S.E. Quensland Suppliers.

Yeh Neill,
my vermculite square in the middle of the concrete slab will sit 100mm thick.
This means the concrete is totaly isolated from the heat.
Seems watching the concrete does not make it cure any quicker.
Will uncover it on Sunday and pour the vermeculite slab and then leave it covered for another week before I start laying my fire bricks.

i was planning on buying a diamond tipped blade for my drop saw to cut the bricks. From what I can gather so long as the bricks have been pre-soaked it works fine.
I checked out your build Neill. You seem to know your shit from clay so to speak.
Any tips on mixing the vermeculite for my hearth slab?

[david s]

Re: S.E. Quensland Suppliers.

5:1 vermiculite, cement (add a little sand if you want to make it stronger) but remember that the more cement or sand you add to the mix reduces its insulation value. For every 10 litres of vermiculite add around 4 litres of water.

[avago]

Re: S.E. Quensland Suppliers.

Thanks David,
is this vermiculite stuff waterproof?
If not how does one render it without trapping moisture inside?

[david s]

Re: S.E. Quensland Suppliers.

Try to let it dry for as long as possible before working over the top of it. It takes ages to dry out, maybe about 7 firings even after the oven has been cured. Because moisture is trapped under the floor, this seems to be the hardest to remove.

[david s]

Re: S.E. Quensland Suppliers.

If you lay the 4" of vermicrete, leave it uncovered for a couple of weeks to let it dry as much as possible. No it is not waterproof quite the opposite it sucks up water really well because it's full of air. You need to add approx double the amount of water that you would normally use in a normal concrete brew. By the way if you want to make your hearth strong you should keep the concrete moist for at least a week, not just three days..

[avago]

Re: S.E. Quensland Suppliers.

Are you sure on those figures David?
100L of vermiculite will require 40L of water!

[david s]

Re: S.E. Quensland Suppliers.

Yes 4L water/10 L vermiculite is what I use when also adding 4 L sand for strength. When doing the mix for the dome I use 10:1:3 vermiculite,cement, water. This mix is a little drier so it can stand up vertically.Yes it is a lot of water and it needs to be eliminated by evaporation and curing.