Fire Brick Hints And Tips
What Are Fire Bricks? --
Fire bricks are
specially made high temperature bricks for use in fireplaces, circulators, stoves, barbecue grills, furnaces and inserts. They are made from ceramic material and can take up to 2000 degrees. Here is what Wikipedia has to say about fire bricks:
"A fire brick, firebrick, or refractory brick is a block of refractory ceramic material used in lining furnaces, kilns, fireboxes, and fireplaces. A refractory brick is built primarily to withstand high temperature, but will also usually have a low thermal conductivity for greater energy efficiency. Usually dense firebricks are used in applications with extreme mechanical, chemical, or thermal stresses, such as the inside of a wood-fired kiln or a furnace, which is subject to abrasion from wood, fluxing from ash or slag, and high temperatures. In other, less harsh situations, such as in an electric or natural gas fired kiln, more porous bricks, commonly known as "kiln bricks" are a better choice. They are weaker, but they are much lighter, easier to form, and insulate far better than dense bricks. In any case, firebricks should not spall and their strength should hold up well under rapid temperature change."
Since most modern ceramic cookers are good up to this temperature, clearly you can use fire bricks safely in a ceramic cooker. The bricks are sand colored and somewhat fragile. You can take two of them, grind them together and fairly easily turn them to sandy gritty dust. They are not as hard as traditional red clay bricks. The photo to the right is what is known as a "split." It is like a full-sized fire brick, but only half as thick. You may wish to buy both sizes of fire bricks as you come across different uses for them in your ceramic cooking. Also, fire brick can be broken into pieces to create special different sizes. For example, full sized fire bricks cut in half make nice posts to place a second grid on in order to make a raised grid.
Why Would I Use Fire Bricks In A Ceramic Cooker? --
Well, first of all, you do not want to use traditional bricks in a ceramic cooker. They are prone to cracking when exposed to high heat and this cracking can be rather violent. There are also suggestions floating around that a wet brick can explode if heated. We can't say for sure if this is true or not. Informal polls yield mixed results and web searches were inconclusive. We lean towards saying that they will not explode. Perhaps the most persuasive argument came from the person who asked the question, "Do you see exploding bricks in a house fire?" We also found reports on the web of exploding rocks in campfires if the rocks came from a river. But all we found were admonitions against using wet rocks. We found no actual factual information on the topic. In the long run, we usually adopt the "better safe than sorry" approach, so if you are going to use bricks, use fire bricks. However, we can't say that bad things will happen with ordinary bricks.
But why would you want to use any bricks? Well, they can be used to provide a barrier between the hot fire and the food for indirect cooking. Also, they can add ceramic mass to the cooker to help even out temperatures. Finally, they are a safe material to use in propping up grates in order to make raised grates if you don't wish to go to the trouble of using stainless steel washers, nuts and bolts.
Where Can I Get Fire Bricks? --
You should be able to find fire bricks at any good brick yard.
If they build fireplaces where you live, then somewhere nearby there has to be a supplier of fire bricks for the local brick masons. We have occasionally found whole fire bricks in Home Depot and Lowes, but only sporadically. Fire bricks from sources such as brick yards and home improvement super stores are fairly cheap, less than a dollar each.
If you cannot find them locally, as a last resort, albeit a somewhat pricey last resort, you can order a box of six splits
through Ace Hardware. If you have an Ace Hardware store near you, you can order them on the web and have them delivered free to your store. Alternatively, you can just go to
their website at www.acehardware.com order them for home delivery. These particular bricks are made by Rutland and are known as Rutland item 604. You can search on the ACE web site for "Rutland Fire Brick" and you will find them. If you go to your local Ace hardware store, you can ask them to search for Ace item 4066171. The bricks are 9 inches by 4.5 inches by 1.25 inches thick and they weigh almost 4 pounds each. (3 pounds, 12.5 ounces if you must know!) And the price is $18.99 a box. We said they were somewhat pricey, didn't we?
Another source of expensive fire bricks in small quantities is Northern Tool and Equipment.
How Should I Use Fire Bricks? --
The first thing you can use fire bricks for in a ceramic cooker is to raise the cooking level of a pizza stone. If you think about it very long, you'll figure out that in order to use a pizza peel to put the pie on your stone
and then remove it, the stone has to be at a level high enough in the cooker so that it clears the opening. You can't
stick a peel down in the cooker and then expect to get a pizza out. So, for pizza, the bricks serve two purposes: first
to raise the stone and second, to add another layer of ceramic between the pizza and the fire. Adding more ceramic helps keep the stone at a constant temperature for long term cooking of several pies. In the photo on the right above you can see how we have used four fire bricks to provide a base to rest the pizza stone on. First, place a grid on the fire ring and then place the bricks on the grid. Then you can place the pizza stone on the bricks. You might wish to use five bricks to make a larger base for a larger pizza stone as in the photo on the left. You could also put a sixth brick on edge to the front to fill in that gap showing in this photo.
Another reason to use fire bricks in a ceramic cooker is to provide a barrier between the fire and the food for indirect
cooking. Also, we feel it is better to have your drip pan sitting on a layer of ceramic to shield it from the fire, to prevent burning juices, etc. So, starting with the five-brick base shown in the photo above, left, you can add your drip pan and a grate to end up with the setup to the right for indirect cooking. (Again, you could add a sixth brick on edge to fill in the gap between the front brick and the three bricks lying on the lower grid if your drip pan is smaller than what we show, or if you aren't going to use a drip pan at all.)
One last use we can think of is to take a whole fire brick (versus the splits shown in the photos above) and cut it in half. This will result in short pieces which can be used to prop up a second grid in order to make a low-tech raised grid. You can see how this was done in the photo to the right of some spatchcocked chickens cooking on a raised grid. In this case, we wanted to cook direct on a raised grid, so we didn't want to make a ceramic barrier. We just used the halves of the bricks as posts to raise the second grid. You could do the same thing with splits, but whole bricks cut in half provide a more stable prop for the upper grid.