I am building the Mattone Barile per the instructions.
I want to have a stained wooden “mantal” (1"x6" boards) surrounding the 3 concrete hearth slabs. My question is: Would a construction adhesive (liquidnails fuzeit, apparently good to 300f) be a good idea to adhere the wood boards to the concrete? My concern would be if the heat from the oven would degrade the adhesive, or harm the spar urethane finish on the wood. Does the outside edge of the concrete hearth get “hot” during use? Thanks in advance, heres a pic of what I would like (not my oven) https://m.media-amazon.com/images/I/81Q5XRVvrxL. AC_SX425 .jpg
That sounds like a nice finish. The slab exterior does not get hot thanks to the insulation under the hearth firebrick. It acts as a thermal break to keep heat from being absorbed into the concrete and drawn away.
Looking more closely at the photo, there are a couple of things you’ll want to pay attention to:
The wood can be adhered to the slab as you suggest. In addition I’d use finish nails to reinforce the corners, and plenty of wood glue at those joint faces. You won’t have thermal stress from the oven, but you will from sun and weather.
The wood surface needs to be protected with several coats of marine grade polyurethane. I don’t know your local climate, but here in New England that’s something we’d have to renew every few years.
There is a bead of silicone caulk visible along the top edge. A good outdoor, mold resistant product is essential there, and you need to ensure there are no gaps where water could get in between wood and concrete. Leave the bottom edge open so moisture can escape.
There may be other considerations but I think those are the most important ones. Good luck with your build and hope to see photos of that oven as it takes shape!
I did the same thing with my oven but I used concrete anchors with SS bolts to hold the boards in place. I wanted to be able to remove them if needed. (re-finishing, etc.). In the picture I have only two of the SS bolts installed but I have since finished the rest.