The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Fibrament-D?

  • Pin It
APitt92's picture
APitt92

Fibrament-D?

I have built a dome-shaped oven for my backyard kitchen and just deciding what material to buy for the actual cooking surface. I have heard alot about Fibrament-D baking stones, but also many people have mentioned that simply some fire bricks work very well.

Im concerned with three things

-price

-weight

-good results (taste)

 

Please tell me whats best..

polo's picture
polo

I can tell you a bit about firebrick, but not much about a fibrament stone.

Price - I paid $1.15 USD per brick for medium duty firebrick about two years ago. Price probably hasn't changed much.

Size and Weight - The brick's standard size is typically 9"x4.5"x2.5" and they weigh about 8 lbs per brick. If you are concerned about the weight, they do make a firebrick "split" which would be half the thickness (1.25") and half the weight.

Good Results (taste) - Yes, I get very good results from firebrick. I will stop short of making any recommendations without having more information about your oven. 

 

kmrice's picture
kmrice

If you haven't already, go to the forum at Forno Bravo's website: http://www.fornobravo.com/forum/

There is a wealth of information there about what to use for the cooking deck of your oven. Be sure you have plenty of insulation under the deck, or your base will act as an enormous heat sink and you'll have trouble keeping the deck hot enough.

Karl

tananaBrian's picture
tananaBrian

Another option is to use kiln shelves.  They are a quite often the best deal when it comes to cost (not sure how they compare to fire brick or the 'fire brick splits' mentioned above).  I don't know all the types of kiln shelf materials that are out there, but the cordierite (CoreLite etc) type is food grade and works well ...and many places that sell kiln shelves will custom cut them to the size and shape that you want as well.  No reason to go thicker than around 5/8" on them either.  ...Just one more thing to consider.  Oh yeah, don't buy used kiln shelves ...they are probably contaminated with non-food grade yuckies.

Brian

 

kmrice's picture
kmrice

Will kiln shelves have sufficient thermal mass at 5/8"? I don't know much about kilns, but if they have a heat source during the firing, kilns are very different than wood fired ovens.

If you intend to use the WFO for anything other than pizza (bread, meats, caseroles), you remove the fire before cooking. The deck needs sufficient thermal mass (and insulation) so that it doesn't cool down too quickly when you remove the fire. This means that you need sufficient thermal mass to charge with heat, and sufficient insulation to keep the heat from escaping.

With pizza, you have a continuous fire, but, even so, you don't want the deck cooling off under the pizzas or you will have to keep moving the fire and reheating the deck. If the deck goes under about 700, your pizza will suffer. A lot. The main point to a WFO with pizza is having a deck and oven which are much hotter than you can achieve with a kitchen oven.

Unless kiln shelves or fibrament have significantly more thermal mass than brick, I don't think either, at 5/8" or even 1" would suffice unless they were laid on top of brick or something else with additional thermal mass. It does look like fibrament comes in 2" thickness; that might be enough, but I'm not sure.

Another concern with fibrament would be whether it could stand up to the temperatures in a WFO. During firing, the deck can easily get to 850 f, 900 f, or higher. AWMCO's website says "Temperature Limit, Continuous Use 750°F." 750 is about ideal for cooking pizza, but during firing, the deck gets much hotter.

Thermal mass and insulation are critical, and, with the deck, it can be very difficult to make corrections if you don't start with enough.

Do look at the Forno Bravo site. TFL is a fantastic resource, but the Forno Bravo is all about WFOs and has a huge amount of information available from people who, like you, have built their own ovens. This subject has been discussed there extensively, I believe.

Karl

ClimbHi's picture
ClimbHi

I kinda agree with Karl, but your original question doesn't give enough information to get a good answer. You say you've already built your oven, but give no information about the construction details. The ideal is to have the deck be pretty much the same thermal mass and insulation factor as the rest of the oven so it's neither hotter or colder than the rest of the oven during the cooking cycle. Not quite so important for fire-in cooking (e.g. pizza), but much more so for fire-out baking (e.g. bread). Usually the cooking surface is integral to the deck and is built before the walls and dome, but there's no reason you can't do it the other way around -- provided you planned for it and set your door height to allow for the higher deck.  (The ratio of door height/oven ceiling height is pretty important for proper draw and heating.) If you did, that pretty much dictates your choice between brick and baking stone since the thickness will have been predetermined. As for the baking stone option, even unglazed clay tile will work fine over a decent deck, and will be cheaper. Also, if your deck already has sufficient thermal mass, the thickness of the cooking surface is less important from a mass standpoint.

Hope that helps.

ClimbHi
Pittsburgh, PA