Insulation board or no insulation board

[Rimrock]

I am installing a Mugnaini Prima 100 masonry kit and I have been reading posts on this forum, since I cannot find a forum dedicated to Mugnaini. I see frequent mention of insulation board being installed under the oven in posts on this forum. There is no mention of insulation board in the Mugnaini installation manual. The layers are: 4” concrete, 3” sand, 3” concrete, then the Masonry kit gets installed directly on the concrete. The Mugnaini masonry kit provides a floor and dome-shaped walls, all made from refractory material. So why do most of the pizza ovens discussed here use an extra layer of insulation board under the oven floor?

[Gulf]

I looked at the Mungaini Kit Instruction Manual. The under floor methods described there in are not in line with the best practices for an efficient oven. The concrete underneath the brick oven floor will suck the heat from the oven causing extreme heat up times for the floor. The dry sand underneath the concrete is an inefficient insulator. If you decide to follow this manufacturer's installation plans do not use standard concrete with large gravel. Standard concrete can spall when subjected to intense heat.

Although you did not purchase your kit from Forno Bravo, I recommend that you go to the Forno Bravo Resources page. You will find a lot of free information and how to videos there. Keep looking at several threads on here discussing under floor insulation. Also note that we advise elevating the insulation and including weep holes to help eliminate moisture.

[Rimrock]

Thanks for the suggestions. I will take a look at the Forno Bravo resources page.