Isol insulation adhesive

[Les]

What is the point of gluing the isol board to the hearth? It seems to me that with all the weight, mortar and insulation that it won't move. For those that have used this product, did you use the adhesive?

Les...

[dmun]

I put my insulation boards down on the wet concrete slab surface. Solid as a rock. My brick floor I laid loose on top of the insulation, and they creaked and groaned as I stood on them to build the oven, but they seem pretty solid now.

You're right. It's like the riggers say: Gravity always wins.

[Hendo]

I used a high temperature adhesive - Kaogrip - for two reasons - mainly to level my slab and give the Cal Sil sheets a 100% flat surface to sit on. Putting the sheets down on the slab without the glue there were many hollow sounding areas.

The other reason was practical - I figured I'd probably bump the sheets and open up gaps when laying the floor etc, and the glue held them in position during this procedure.

[wlively]

Ditto Hendo's concerns. Although I just used the plain old Heatstop mortar.