Dome Insulation?

[jota112233]

Re: Dome Insulation?

Thanks for the replies Gents.

Still in the planning stage at the mo, othern than having laid my foundation.

Regards
Jon
Cardiff

[nissanneill]

Re: Dome Insulation?

Dean,
just be careful not be duped into buying an expensive alternative to vermiculite.
I was lead to believe that vermiculite was used not as a fertilizing agent in nurseries, but to bulk out the potting mix as well as retaining copious quantities of water for the plants.
Just make sure that the insulation is not as Davd says silicone treated.

Neill

[dmun]

Re: Dome Insulation?

No, that's exactly the right stuff. The silica in the vermiculite is different from the waterproofed stuff that's sold for domestic insulation: It's treated to resist water absorption, which is how the vermculite turns into vermiculite concrete, by mixing portland and water with it.

[jota112233]

Re: Dome Insulation?

Hi Dmun

Regarding " We are warned off the silicone treated stuff used in domestic insulation, but that isn't that common" why is that?
I've found the attached which sells for about ?10 forr 100 litres which is pretty good.

Heres a link

http://www.dupre-vermiculite.co.uk/Datasheets/MEDIUM%20GRADE%20VERMICULITE.pdf

[Wheels1974]

Re: Dome Insulation?

I guess there are a variety of refractory insulations on the market such as "VERMICULITE" and "PERLITE" I was just told that there is another called "SHERLITE or SHERLIGHT" (Sorry I'm not exactly sure how you spell it.) I was told that it's made especially for the construction of wood fire ovens and the likes as opposed to "VERMICULITE" and "PERLITE" which was originally used as a fertilizing agent often found in nursery's. Apparently this "SHERLITE" works just as well as the other two mentioned and it's just a matter of mixing it with water until it reaches a toothpaste consistency. The bonus with "SHERLITE" I have been told is that it's so much easier to work with as opposed to "VERMICULITE or PERLITE"

My query is has anyone heard of this stuff called "SHERLITE" or better still has any one used it?

P.s. Sorry about not knowing the correct spelling Re: "SHERLITE"

Regards
Dean

[SteveP]

Re: Dome Insulation?

I didn't use vermiculite as I couldn't find any. I did find a lot of perlite at a nursery supply warehouse and used that and has worked great. I believe the price was very reasonable at $9 for 4 cuft. I ended up using 4 to 5 bags.

[dmun]

Re: Dome Insulation?

whatever void space is left between the insulated dome and the walls can be filled with just vermiculite/sand, correct?

Keep sand out of the insulation layer. Sand isn't an insulator.

i am looking to buy vermiculite to fill in over the refractory insulation i packed around the oven (4") is there specific kind to use or not to use? or is it all the same?

We are warned off the silicone treated stuff used in domestic insulation, but that isn't that common. The stuff supplied for garden soil enhancement, or pool lining, or packing is just fine, and particle size doesn't seem to make much difference.

[antonio cefalo]

Re: Dome Insulation?

i am looking to buy vermiculite to fill in over the refractory insulation i packed around the oven (4") is there specific kind to use or not to use? or is it all the same?

thank you

[beckj]

Re: Dome Insulation?

If you create a void space around the dome with chicken wire, and fill that void with loose vermiculite, then you stucco/mud on top of that. That total thickness should be about 4-5 inches, correct? And also, whatever void space is left between the insulated dome and the walls can be filled with just vermiculite/sand, correct? Or does the void have to be filled with solid material, say vermiculite/concrete?

Thanks to anyone out there for an answer!

-John

[james]

Re: Dome Insulation?

Very good advice Dutch. Thanks.
James

[Dutchoven]

Re: Dome Insulation?

I could be wrong but I think dmun and asuda are referring to pouring in loose vermiculite...if you use it as vermiculite concrete you can appy that directly onto the blanket somewhat like stucco...in that case you might want to use type N mortar mix as opposed to just portland cement...which will help it stick better on the more vertical surfaces...then you can just stucco the exterior
Dutch

Thanks, I will position the wire out from the blanket and then pour the vermiculite concrete so that the wire holds it in. I can then render on top of this once gone off.
Picture of oven as it stands today, hopefully a pizza is not too far away!

[RyH]

Re: Dome Insulation?

Thanks, I will position the wire out from the blanket and then pour the vermiculite concrete so that the wire holds it in. I can then render on top of this once gone off.
Picture of oven as it stands today, hopefully a pizza is not too far away!

[asudavew]

Re: Dome Insulation?

I built a wire cage and covered it with screen. Then I poured my my verm in.

I still need to cover it with mortar and stucco.

[dmun]

Re: Dome Insulation?

If you can build a freestanding armature that would hold stucco (render?) then you wouldn't need to solidify the vermiculite: you could just pour it in loose before putting the last of the scratch coat on at the top.

This said, most people use the chicken wire to hold in the hard-to-work-with vermiculite concrete, and then stucco over that when it solidifies.

[RyH]

We finished building the oven over the weekend, next stage to insulate.

Do I put the chicken wire over the insulating blanket tightly or do I have it 4" away from the blanket leaving a gap to hold the vermiculite concrete?