I bought a pallet of the firebrick from a local building supply store which brought the price down some. On the smoker side, I installed them on their sides, which gave me around 50% more surface area. I figured the firebrick didn't need to be 3" thick on the smoker side. Here is the site I used for my doors when the couple local welders wanted to charge me $2000 to make doors for me... http://www.hallmann-sales.com/access-doors/ad-uninsulated-fire-rated-access-doors.htm