New Project.

[trenchn]

Hi Guys,
I am about to embark on a new project. Like many others I like to use recycled materials where possible.
I am planning the following:
I have a metal, highly insulated, base, that I will lay quarry tiles on for the oven floor. This should give adequate insulation.
I am then planning to use 100mm thermalite blocks ( this is a light weight insulating block made mainly from ash), for the walls which will then be lined with slate tiles.
My initial thought was to do a barrel vault type top made of bricks and then insulated over with vermiculite and cement.
However I am hoping for some suggections as to better options bearing in mind my rrecycling desire.
The interior dimension will be around 600 mm wide by 750mm long.
I am limited by space and don't really want a round oven as they take up more space and I have already built a dome type oven which was attacked by frost and eventaully crumbled.
My questions are: How can I make a cheap, simple form to build my vaulted roof over?
Any alternative ideas for the roof, materials, design, etc.
general comments on my proposal.
Thanks
Nick

[brickie in oz]

Re: New Project.

I am then planning to use 100mm thermalite blocks ( this is a light weight insulating block made mainly from ash), for the walls which will then be lined with slate tiles.

Is this for the oven itself?
Thermalite blocks are made from aerated concrete.

[trenchn]

Re: New Project.

The oven will be lined with slate tiles. I am only planning short cooking times, so insulation is not crucial. Do you think the thermalites will be a problem? I think I was confusing them with clinker blocks.
Thanks for replying.
Nick

[stonecutter]

Re: New Project.

The slate will break up from the thermal cycling as will the quarry tile on the floor.

[stonecutter]

Re: New Project.

Save the tile and slate for outside finishes and get some firebrick or castable refractory material. If that is not in the budget consider building a clay/earth oven, which you can insulate and finish the same as one built with refractory brick or cast.

[david s]

Re: New Project.

"My questions are: How can I make a cheap, simple form to build my vaulted roof over?"

Get some polystyrene fruit boxes and pile sand over the top of them until you get a form that you like. Adding 10% water to dry sand makes it shape and compact nicely. Pretend you are 10 and are at the beach.

[trenchn]

Re: New Project.

I thought that slate could withstand very high temperatures
"Heat Tolerance
Slate countertops do not scorch, char or discolor if you set hot pots and pans on them. In fact, it is so resistant to heat, you can build fireplace boxes and hearths from slate and indefinitely build fires in the fireplace with no chance of the slate cracking or breaking.



Read more: How Much Heat Can Slate Handle? | eHow How Much Heat Can Slate Handle? | eHow.

A: Quarry tile does not have a glaze or factory applied coating. ... is a valuable choice for countertops and fireplaces because it can withstand high levels of heat.

Is this info wrong?
I have already built and knocked down an earth oven and wanted to try something else, but on a tiny budget.

[trenchn]

Re: New Project.

Great idea David, Thanks. I think I will use some old thermal board that I can shape to the arch and then build over it and remove when the arch is dry.
Do you agree with stonecutter about the slate and quarry tiles. According to various sites on the internet, both can withstand high temperatures.
Thanks
Nick

[mrchipster]

Re: New Project.

Great idea David, Thanks. I think I will use some old thermal board that I can shape to the arch and then build over it and remove when the arch is dry.
Do you agree with stonecutter about the slate and quarry tiles. According to various sites on the internet, both can withstand high temperatures.
Thanks
Nick

Nick, quarry tiles and slate will break down and quite quickly, firebrick and soapstone are just about the only two man made items that will hold up.

The clay, earth oven will need to be protected from rain but it will be better than the slate/quarry tile version. And you could use the slate and tile as a decorative outer layer. If you want a nice floor, pop fo some firebrick there. You should be able to get a good deal of floor coverage with 20 or so bricks and that is where you would cook.

When you make the arch put some shims under it so you can remove the shims and then drop the arch to make it easier to remove.

Chip

[trenchn]

Re: New Project.

Yes, having explored the forum a bit more, this was the conclusion I came to.
I think I will look for some firebricks from the inside of an old night storage heater.
Thanks for your input.
Nick

[stonecutter]

Re: New Project.

The heat that slate and granite counters are subjected to are very brief. Also, the only way it us used for fireplaces is for the surround..not the box. Even soapstone tile won't last...it will if it is thicker than 2" though.

If you use tile and slate for the oven surfaces
, you will add it to your demolition experience.

[trenchn]

Re: New Project.

Hi Stonecutter, Yes I see that now. Complete rethink required. Thanks for your input.
I am now going to try and source some of the fire bricks used in old night storage heaters here in the UK, I will use them for the floor and sides. I haven't decided on the arch yet. Any low cost suggestions welcomed. Ordinary firebricks are really expensive here.
Thanks
Nick

[brickie in oz]

Re: New Project.

I am now going to try and source some of the fire bricks used in old night storage heaters here in the UK, I will use them for the floor and sides.

This one comes up from time to time and there have been a few builds on here about them, they never get back to us about how they went though.

As far as Im aware the bricks inside electric storage heaters are made from portland cement based concrete, sure they will hold the heat for a storage heater but if they are made from normal concrete they will spall very rapidly with the direct flame and heat of a wood fired oven.

[trenchn]

Re: New Project.

Hi Al,
I used this type of brick for the floor of my first oven with no problems, so I'm hoping they will be OK.
I have got to find some first!!
Thanks
Nick

[stonecutter]

Re: New Project.

When you say that you are undecided on the arch, do you mean what to do for the form? If so, it doesn't get much cheaper than sand.