Constructing a backyard pizza oven? Outdoor kitchens are very popular today, and we are often asked about which products to use. While you can certainly purchase a fully constructed (or partially assembled) oven, if you're handy you can build your own, or hire a reputable contractor to do so. There are many guidelines available online, but essentially you are going to start with a base of brick topped with solid masonry such as concrete and precast concrete. Then you will need to build your firebox. The hearth should consist of refractory grade firebricks, or you can cast your own base using the Heat Cast 40 product (you'll need 20 lbs. per square foot when applied 2" thick, which is what the manufacturer recommends for a minimum thickness), or Plicast Tuff Mix KK. Similarly for your walls in the oven, use refractory firebrick or castable Heat Cast 40, Plicast Tuff Mix KK, Plicast KL 3000, or Plicast Hymor 3000 KK. If using refractory brick, use the dry mix Heat Stop 50 (or in a smaller container sold as Heat Stop II) as refractory mortar between the bricks. If moisture is present, you'll want to use one of these two non-water soluble products.
You can also add extra insulation and fill gaps by parging another refractory product, Insul Stick, on the sides of your oven, providing extra insulating value and strength. Insul Stick should be applied 1/4" to 1/2" thick (you will need 2.5 lbs. per square foot when applied 1/2" thick). An alternative wet (premixed) product is Plistix SR-68 with a plaster-like consistency.
You can also use Heat Cast 40 to cast your dome, again with a minimum thickness of 2". For insulation over your dome, under the hearth or behind the firebox, use Insul Cast, another castable refractory product made by the manufacturer of Heat Stop. It is ideal as an insulator for bread or pizza ovens, and should be applied 2" thick as a minimum. You will need approximately 6 lbs. per square foot when applied 2" thick. All of these dry mix products are mixed with water just as you would with regular cement.
Some people like to add another lighter layer of insulation over the top of the dome, and you can use Fiber Frax ceramic blanket (8 lb. density) for this purpose. Once this cures, you are ready for your top layer of stucco, brick, stone or other masonry to match your decor. All these products are available in our store. Follow your local building codes and always consult with a professional for questions.