Raising hearth height flush with oven floor.

[pnassar]

I am in the process of building a 100 Primo 2G. I am ready to poor the hearth with a bowed front ledge as in the FB installation guide. I am not quite sure how to accomplish two steps and seek the members expert advice !

First, after assembling the modular unit on the fire board do I trim the fire board flush with the outside edge of the cast modular unit and then drop the insulation down and adjacent. Or, do I let the fire board extend out and then bring the insulation and stucco down on top of the fire board surface? I think I have seen picture of both. The installation diagram looks like my first description.

Second issue. I would like to finish the top of the ledge and surface surround the oven with a grant top that ends up flush with the cooking surface of the oven. That will require material to raise the surface from the hearth top about 4 3/4 inches. The fireboard (3") plus the cooking floor fire brick (3") less the thickness of the granite (1 1/4"). What material do you recommend for this 4 3/4" lift ? Though about doing a second pour with lightweight concrete but there is probably an easier way...

Thanks greatly for all responses !

Pete

[Toomulla]

You haven't said whether the oven is to be enclosed or not. Raising the entry and surround to be level with the floor of the oven may create a basin that will hold any water that enters at joints etc. water entry at joints is not desirable anyway but the raised surround may compound the problem. A drainage layer installed below the surround that allows water to wick to the edge may help