Win a copy of For the Love of Paw Paws this week in the Fruit Trees forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • r ranson
  • Anne Miller
  • paul wheaton
stewards:
  • Jocelyn Campbell
  • Mike Jay Haasl
  • Burra Maluca
garden masters:
  • James Freyr
  • Joylynn Hardesty
  • Steve Thorn
  • Greg Martin
gardeners:
  • Carla Burke
  • Dave Burton
  • Pearl Sutton

cob oven: perlite or sawdust for insulation?

 
Posts: 32
Location: Seattle, WA
3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I'm building a cob oven and trying to decide what to use for the insulation layer. Sawdust is free ... is there a compelling reason to use perlite?
 
pollinator
Posts: 1479
Location: Vancouver Island
49
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Patrick Mann wrote:
I'm building a cob oven and trying to decide what to use for the insulation layer. Sawdust is free ... is there a compelling reason to use perlite?



It depends on how you are going to use it. If you are mixing sawdust with the clay (or cob) to make an insulating layer, that can work. If you are filling a void with just sawdust, it won't. The sawdust in the clay may burn out but the voids left are still insulating. Perlite won't burn and so is more flexible.
 
Pat R Mann
Posts: 32
Location: Seattle, WA
3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I'd mix either materials with clay slip. Some people seem to have a preference for one or the other and I'd like to know why. It's more important to me to get max insulative value than to save a bit on the materials.
 
Posts: 120
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Patrick
The group I worked with used lots and lots of finely chopped straw mixed with pudding consistency clay slip.
The few reports I've had of the oven is that it fires up hot and decreases its heat evenly.
ahhh..playing with cob/clay is so much fun
Enjoy
 
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!