really cheap floor insulation?

[johnnybrewmeister]

apologies in advance if this is a really stupid question (likewise if it's been posted previously), but could a really easy & cheap insulated floor be made out of pink fluffy wall insulation sandwiched between 2 pieces of concrete backer board?

[brickie in oz]

Re: really cheap floor insulation?

apologies in advance if this is a really stupid question (likewise if it's been posted previously), but could a really easy & cheap insulated floor be made out of pink fluffy wall insulation sandwiched between 2 pieces of concrete backer board?

no!!....................

[david s]

Re: really cheap floor insulation?

I used fibreglass insulating bats and insulating firebrick supports under the firebrick floor of my first oven. When I dismantled it to give to a friend there was no perceptible deterioration of the fibreglass insulation. Others have reported that the backing, or binders if it has some, burns.

[Ken524]

Re: really cheap floor insulation?

Really cheap insulation that works:
Vermiculite: $12-$15 per 4 cubic feet
Portland cement: $7 per 50 lbs.

Vermiculite/Portland has been used by dozens (hundreds?) of Pompeii builders with excellent results. Even better is to spend the extra dollars for FornoBravo Board or CalSil board. The insulation under your floor is the most important part of your build.

I'm all for promoting creativity, but your oven floor is NOT the place to experiment. If you screw up this step, there is no easy way to fix it short of a complete tear-down.

[david s]

Re: really cheap floor insulation?

In defence of using fiberglass bat insulation I used it on my first oven because it was free and I made the floor easily removable to access it. I now always use vermicrete or foamcrete or a combination of both.
Fiberglass insulation has been designed to insulate ceilings and presumably has a specific temperature range. The manufacturers should be able to provide this information, but I would guess that it is not designed for higher temperatures. It does compress easily so some method of preventing this is required. I used supports of insulating firebrick.The one huge advantage of fibreglass is that it does not absorb water like calsil board,mill board, vermicrete or perlcrete.
I can say that the fibreglass insulation I used worked pretty well, although that was only for about three years. Have no idea how it would hold up in the long term.
I wish I could buy vermiculite for only $12. I have to pay $40. And a 20kg bag of cement is $10

[V-wiz]

Re: really cheap floor insulation?

Here you go. Call them Pacific Insulation - Industrial Products - Pipe Insulation, Air Handling/HVAC, Industrial Insulation, Commercial Insulation, Insulation Fabrication. They are in Socal. Each board of Calcium Silicate costs $10. Thats pretty cheap to me? Decide how much you need and get it, do it right the first time around.

[Tscarborough]

Re: really cheap floor insulation?

Perlite/vermiculite concrete at an 8-1 ratio is the cheapest insulation workable in the States, at least.

[david s]

Re: really cheap floor insulation?

If you look at foam concrete it is significantly cheaper.

[Tscarborough]

Re: really cheap floor insulation?

Yes, but us mortals can not conjure it.

[david s]

Re: really cheap floor insulation?

It's easy. it's just like folding egg whites into a cake mix.

[johnnybrewmeister]

Re: really cheap floor insulation?

Here you go. Call them Pacific Insulation - Industrial Products - Pipe Insulation, Air Handling/HVAC, Industrial Insulation, Commercial Insulation, Insulation Fabrication. They are in Socal. Each board of Calcium Silicate costs $10. Thats pretty cheap to me? Decide how much you need and get it, do it right the first time around.

Thanks for the pointer, I sent them an email to get prices (local San Diego store).
I looked at vermiculite, but at my local Homer Depot store it is $20 for 2 cu ft. Not exactly cheap, since I'm est. I'd need at least 5 bags, plus cement, etc. would come close to paying full price for FB board. Always looking for cheap...er...um...creative ways to DIY.

[deejayoh]

Re: really cheap floor insulation?

Vermiculite is generally available in larger quantities and at cheaper prices from nurseries. You might want to check there. HD charges ridonkulous amounts.