#11  
Old 07-09-2008, 06:31 AM
Wlodek's Avatar
Apprentice
 
Join Date: Jul 2007
Location: England's Lake District
Posts: 134
Default Re: Insulated Pad question

I take it 2in of FB is not enough then? Has anyone combined FB with vermiculite-concrete?

W.
Reply With Quote
  #12  
Old 07-09-2008, 06:38 AM
dmun's Avatar
Moderator
 
Join Date: Jul 2005
Location: New Jersey USA
Posts: 4,216
Default Re: Insulated Pad question

Two inches of cal-sil insulation is enough. You can use more if you want, but for home use, that's a good insulation layer.
__________________
My geodesic oven project:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #13  
Old 07-09-2008, 06:44 AM
Wlodek's Avatar
Apprentice
 
Join Date: Jul 2007
Location: England's Lake District
Posts: 134
Default Re: Insulated Pad question

Many thanks ... last minute wobbles and insecurities here ...

The support base is ready here ... all in local stone, came out solid like a bomb shelter but with a certain charm, will post some photos soon.

Best wishes,
W.
__________________
"Carpe diem." - Fish of the Day (The Uxbridge English Dictionary)
Reply With Quote
  #14  
Old 07-10-2008, 07:50 AM
Apprentice
 
Join Date: Jul 2005
Location: Toronto
Posts: 106
Default Re: Insulated Pad question

I am not sure I like the vermicrete on the entire pad so I was thinking of pouring say 3-4" of concrete and then pouring the vermicrete mixture in the centre of the pad where the oven hearth would be and filling in around it with concrete again. That way when I build the facade and enclosure I have real concrete to adhere to. Anyone see any potential issues with this approach? I might even add the insulation board over the vermicrete for extra insulation.

Thx
Reply With Quote
  #15  
Old 07-10-2008, 08:08 AM
DrakeRemoray's Avatar
Il Pizzaiolo
 
Join Date: Mar 2006
Location: Littleton, CO
Posts: 1,211
Default Re: Insulated Pad question

TDIBratt, this should work. It is in the plans as the "island hearth" method. I would make sure that the insulating layer extends beyond the walls of the oven 4 inches, but beyond that it does not add anything and does cause some problems with attaching a facade.
Reply With Quote
  #16  
Old 06-11-2009, 09:49 PM
Abear's Avatar
Peasant
 
Join Date: Apr 2009
Location: Tomball, Tx
Posts: 32
Default Re: Insulated Pad question

Quote:
Originally Posted by Dutchoven View Post
.portland and vermiculite is good for the hearth insulation but I would recommend mixing vermiculite with "Type N" masonry mortar for the outside of the dome...type N is a bit softer and sticks better to vertical surfaces...
Dutch
Do you use the same ratio for above the dome (5:1 vermiculite: Type N mortar) as below the hearth just substituting the portland for Type N?
Reply With Quote
  #17  
Old 06-11-2009, 09:56 PM
Abear's Avatar
Peasant
 
Join Date: Apr 2009
Location: Tomball, Tx
Posts: 32
Default Re: Insulated Pad question

On that note, another question seeing I'm up to the insulated hearth phase: I bought 3 bags of vermiculite (12 cu. ft. total) and plan on filling a form 24 sq. ft. 6" deep. If all goes well, it should be enough but I fear compression and volume loss once the mixture gets wet. Should I buy more bags before I start or will I get a true 12 cu. ft. of material to use after mixing? Seeing it takes awhile to set, is it OK to add to it later if I due run short and need to make a trip to the store?
Reply With Quote
  #18  
Old 06-12-2009, 01:48 AM
Serf
 
Join Date: May 2009
Location: australia
Posts: 15
Default Re: Insulated Pad question

I did my insulating layer yesterday and used 5.33 100litre bags. My hearth is 1500mm x 1800mm x 170mm. Sorry about the metric measurements but that is what I use.
I hope this helps.
Reply With Quote
  #19  
Old 06-12-2009, 12:29 PM
Wlodek's Avatar
Apprentice
 
Join Date: Jul 2007
Location: England's Lake District
Posts: 134
Smile Re: Insulated Pad question

Just to report (9 months later) that my hearth construction seems to be working well, there are no structural problems, and the insulation seems to work really well, with the oven hot enough to cook at 200C at noon the day after a dinner time pizza the previous day.

The refractory oven floor rests on some 2in of dry sand, followed by 2in of a high-temperature insulation board, which lie on 4in layer of breeze blocks. The breeze blocks rest on a cement board supported by a number of standard pre-stressed concrete lintels. The bottom of the cement board is always cool to touch even if the oven is a mad inferno.

Once again, many thanks to this community for your support and excellent advice. I am truly indebted to you all.

All the best,
W.
Reply With Quote
  #20  
Old 06-14-2009, 07:51 AM
Dutchoven's Avatar
Master Builder
 
Join Date: Apr 2007
Location: Mississippi
Posts: 931
Default Re: Insulated Pad question

Quote:
Originally Posted by Abear View Post
Do you use the same ratio for above the dome (5:1 vermiculite: Type N mortar) as below the hearth just substituting the portland for Type N?
Abear
That recipe should work fine...some builders try to squeeze in more vermic for a better insulation but there comes a time when it would get very hard to work with on the outside of the dome.
Good luck and all the best!
Dutch
__________________
"Making the simple complicated is commonplace; making the complicated simple, awesomely simple, that's creativity. " Charles Mingus
"Build at least two brick ovens...one to make all the mistakes on and the other to be just like you dreamed of!" Dutch
Reply With Quote
Reply

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
question about the sauce recipe on this site... Momo Pizza 8 01-16-2008 07:14 PM
Insulated Hearth Question jcg31 Newbie Forum 7 09-29-2007 07:03 AM
Chimney / Flue Question.. johnrbek Pompeii Oven Construction 1 02-20-2007 03:07 PM
Pouring Hearth Question telehort Getting Started 7 01-29-2007 09:20 AM
Construction of Chimney question dmun Design Styles, Chimneys and Finish 0 07-18-2005 08:08 AM


All times are GMT -7. The time now is 04:02 AM.

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