#1  
Old 08-27-2010, 01:03 PM
Serf
 
Join Date: Jul 2010
Location: washington
Posts: 16
Default sawdust vs. vermiculite insulation

hey oven, pizza, bread, building lovers. i hail from the olympic peninsula in washington.

i have taken part in building 3 cob ovens at this point, enjoyed baking in all but have been disappointed in their ability to hold heat, especially in the 475 degree range.

i have just finished building a 27 by 32 oven and recently got a lot of small wood chip/sawdust material. i was planning on doing 6 inches of insulation with the chip sawdust and clay but i am beginning to think i might be much better off with vermiculite. i insulated the hearth with vermiculite portland and layer of 3 1/2 inch bottles on their side.

the sawdust was free but im thinking i might want to just spend the extra for a better insulator. thanks.

mark
Reply With Quote
  #2  
Old 08-28-2010, 11:50 AM
Neil2's Avatar
Il Pizzaiolo
 
Join Date: Oct 2006
Location: Vancouver Island
Posts: 1,374
Default Re: sawdust vs. vermiculite insulation

You could keep a book to take bets on the sawdust catching fire before rotting.
Reply With Quote
  #3  
Old 08-28-2010, 01:02 PM
Serf
 
Join Date: Jul 2010
Location: washington
Posts: 16
Default Re: sawdust vs. vermiculite insulation

thanks for your friendly advice. just trying to keep it cheap and stay out of the hardware store.
Reply With Quote
  #4  
Old 08-28-2010, 01:30 PM
david s's Avatar
Il Pizzaiolo
 
Join Date: Mar 2007
Location: Townsville, Nth Queensland,Australia
Posts: 4,756
Default Re: sawdust vs. vermiculite insulation

Kiln builders often use sawdust as an insulating material. They fire to temps way higher than we do. Maybe the sawdust burns, depending how close it is to the fire source and how high the temp goes, but what does it matter if it burns anyway, the result is a void which heat does not readily pass through.
Reply With Quote
  #5  
Old 08-28-2010, 03:30 PM
Serf
 
Join Date: Jul 2010
Location: washington
Posts: 16
Default Re: sawdust vs. vermiculite insulation

yeah, thats ultimately what you want. a friend recommended using straw which will do the same thing but provide more airspace, mix easier with the clay slip and be faster to apply.
Reply With Quote
  #6  
Old 08-28-2010, 07:44 PM
dmun's Avatar
Moderator
 
Join Date: Jul 2005
Location: New Jersey USA
Posts: 4,216
Default Re: sawdust vs. vermiculite insulation

Insulating firebrick voids are made with sawdust, but they are fired to a high enough temperature to completely burn the sawdust to create holes in the brick. Any plan which leaves the sawdust in contact with hot masonry is doomed to fail, imo.
__________________
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
  #7  
Old 08-29-2010, 02:16 PM
Neil2's Avatar
Il Pizzaiolo
 
Join Date: Oct 2006
Location: Vancouver Island
Posts: 1,374
Default Re: sawdust vs. vermiculite insulation

"thanks for your friendly advice. just trying to keep it cheap and stay out of the hardware store."

Vermiculite (or perlite) is not that expensive. Check with local plant nurseries.
Reply With Quote
  #8  
Old 08-29-2010, 04:08 PM
Journeyman
 
Join Date: Jun 2009
Location: minnesota, usa
Posts: 472
Default Re: sawdust vs. vermiculite insulation

on another thread someone mentioned McMaster-Carr as a source for Vermiculite. I needed some recently so I ordered a bag instead of driving all over town trying to get it from a nursery. IIRC, the 4 cubic foot bag was ~$30 including shipping and was on my doorstep in three days. Hard to beat that for easy, efficient and cheap.
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
Vermiculite only insulation? shepster Pompeii Oven Construction 17 09-23-2013 02:24 PM
Vermiculite vs perlite for insulation under the oven floor mikesuttie Getting Started 13 06-03-2010 02:35 PM
fiberglass insulation between concrete and vermiculite insulation layer pabsey Introductions 6 07-19-2009 10:47 AM
Insulation question - loose or solid vermiculite covering? jammyweb Newbie Forum 12 06-23-2009 03:57 AM
Bedding brick hearth to vermiculite insulation nissanneill Getting Started 5 05-22-2007 06:41 PM


All times are GMT -7. The time now is 11:10 AM.

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