The most common types of firebrick on the market are low and medium duty - which is great since our wood fired oven kits can use either type of brick. We PREFER that you use a MEDIUM DUTY firebrick, but if you have to use low duty, that will be okay.
If you have 6 minutes to spare and want to learn some great information about firebrick, be sure to read this article by Jim Wunch of Larkin Refractory Solutions (an Authorized BrickWood Dealer). It’s probably the best written article about firebrick and Jim does an excellent job to simply explain the differences between the different types and styles of Firebrick.
For more information then you’ll ever need to know about Fire Brick, be sure to read this action-packed page by Jim Wunch.