Installing Insulation Board

[gsanto]

I am building a 42" Pompeii WFO using the plans that FB provides. The plans go into detail with the Vermiculite method and applying a thin underfloor paste for the cooking floor. It also shows a insulation board placed on top of a wet hearth. My hearth is dry. MY QUESTION: If your hearth is dry and your using insulation board, is it OK to just place the board down and then place the 18" x 18" bricks on top? This means that the igloo is just "floating" on top of the hearth and there is nothing sticking it in place. I guess the weight would keep it all in place but not sure how to proceed. If I need to level things what should I do in this situation. I hope the board comes very flat??????

Greg

[Les]

Re: Installing Insulation Board

Greg,

You can level the board using some dry clay and a notched trowel. You may have to shuffle them around a bit to get it level. Just sit the floor tiles on top - trust me, it will not go anywhere.

[GIANLUCA]

Re: Installing Insulation Board

I did the same all dry and my floor bricks were suprisingly level

[david s]

Re: Installing Insulation Board

The problem is that the firebricks for the floor are often of an uneven thickness. The clay layer under them (wet or dry) allows you to achieve a flat floor surface. Usually the mix is a 50/50 sand, clay layer.