#1  
Old 06-27-2011, 01:41 PM
Peasant
 
Join Date: Jan 2009
Location: New York
Posts: 26
Question FB Board under floor AND dome?

I just received my FB board and I am ready to build my Pompeii oven, finally.

However, the FB board seems softer than I expected. I am not sure that this material will support the weight of the dome and the vent. Maybe it is only supposed to be under the floor and the dome rests on the concrete foundation.

Any insight would help, I am ready to go if I can figure this out...
Reply With Quote
  #2  
Old 06-27-2011, 01:49 PM
Les's Avatar
Les Les is offline
Il Pizzaiolo
 
Join Date: Sep 2005
Location: Carson City, NV
Posts: 2,862
Default Re: FB Board under floor AND dome?

The board can support the weight. You need the dome insulated from the hearth. When you say softer, what exactly do you mean? In no way is the stuff like concrete but it should be fairly firm.
__________________
Check out my pictures here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


If at first you don't succeed... Skydiving isn't for you.
Reply With Quote
  #3  
Old 06-27-2011, 02:08 PM
Peasant
 
Join Date: Jan 2009
Location: New York
Posts: 26
Default Re: FB Board under floor AND dome?

By soft I meant that my finger can leave an imprint. I did not expect it to be like concrete. Not exactly sure what I expected, but the dome will probably weight a half ton or so and all that weight will be on the 4 1/8" ring of my fire brick. Just didn't seem logical to me.

Did you use FB board without any issues?
Reply With Quote
  #4  
Old 06-27-2011, 02:21 PM
GianniFocaccia's Avatar
Il Pizzaiolo
 
Join Date: Jun 2009
Location: Disneyland, CA
Posts: 1,521
Default Re: FB Board under floor AND dome?

The board you got will be fine. I'm sure the FB folks would not send out an unsuitable product. Yes, the board will seem too soft to support the entire weight of your oven, but this is a common perception. Just make sure you don't let any portion of your dome (and entry) come into direct contact with anything other than insulation. Any contact will cause heavy losses of heat through conduction which translates into excessive wood requirements during heat-up and rapid loss of residual heat.
Reply With Quote
  #5  
Old 06-27-2011, 02:30 PM
Peasant
 
Join Date: Jan 2009
Location: New York
Posts: 26
Default Re: FB Board under floor AND dome?

I thought that contact with the concrete might act as a "thermal short", but I was more worried about the weight.

Since it looks like its OK I will proceed. Thanks

When you lay down the FB board should you level with sand or fire clay?
or
Maybe the bricks should be leveled on top of the FB board?

I noticed that the fire brick thickness seems to vary enough to show lips...
Reply With Quote
  #6  
Old 06-27-2011, 05:33 PM
GianniFocaccia's Avatar
Il Pizzaiolo
 
Join Date: Jun 2009
Location: Disneyland, CA
Posts: 1,521
Default Re: FB Board under floor AND dome?

The recommended solution is to level the bricks on the board with a 50/50 blend of fine sand and fireclay, although there's nothing that says you couldn't fill voids between the board and your concrete suppoort slab with the mix as well.

You can mix water with the blend and (notched) trowel it on wet or do what I did: just trowel on dry and tap the bricks with a hammer until you're satisfied. If you wet the bricks from the top it will set your 'mortar' underneath.

You may want to level your floor bricks with a slight slope towards the entryway so if any water gets in it will run out.
Reply With Quote
  #7  
Old 06-27-2011, 06:20 PM
Peasant
 
Join Date: Jan 2009
Location: New York
Posts: 26
Default Re: FB Board under floor AND dome?

Thanks for the pointer Gianni.

I'll see how much flex the FB board has when I lay it down and then I can determine if I need to level underneath it. Since I will be using the FB board I'll probably mix in very little water as to not saturate the board. Just enough to get the mix to flow.

I've spent years thinking about this build and just as many getting my site ready. Now that I am finally at the point where I can build my dome I don't want to leave anything to chance.

Wish me luck
Reply With Quote
Reply

Tags
fb board

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 01:47 AM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
2006/10 Forno Bravo, LLC