#1  
Old 05-12-2010, 06:28 AM
Serf
 
Join Date: May 2010
Location: Northumberland England
Posts: 4
Default Vermiculite mix

Hi All,
New to forum and am halfway through building oven in garden in Northumberland England. Next stage is to put insulation heatrh of vermiculite on top of base. Any advice on mix ratio and what best to put in mix.
Dave B
__________________
Dave B
Reply With Quote
  #2  
Old 05-14-2010, 04:06 AM
Serf
 
Join Date: May 2010
Location: gloucester ma
Posts: 24
Thumbs up Re: Vermiculite mix

Hello Dave B-I also just joined the forum. Building a 1st oven. I believe the site suggested a vermiculite 5:1 portland. I could be wrong. I used a 6:1 as an insulator an insulator around my chimney flue. Mix to an oatmeal consistency. If you use too much water the vermiculite starts to settle. So just add a little more dry ingredients. Good luck. Glosta
Reply With Quote
  #3  
Old 05-15-2010, 12:07 AM
Serf
 
Join Date: May 2010
Location: Northumberland England
Posts: 4
Default Re: Vermiculite mix

Hi Glosta, Thanks for reply and advice. Sun is shining up here, so will be mixing today. Dave
__________________
Dave B
Reply With Quote
  #4  
Old 05-15-2010, 01:18 AM
jota112233's Avatar
Peasant
 
Join Date: Nov 2009
Location: Cardiff UK
Posts: 30
Default Re: Vermiculite mix

I've seen some ratio's here as high as 10:1, but I went for a 6:1 and it seems to be fine.








Jon
Cardiff
Reply With Quote
  #5  
Old 05-15-2010, 03:33 AM
Serf
 
Join Date: May 2010
Location: gloucester ma
Posts: 24
Default Re: Vermiculite mix

Serf-I like how you formed the vermiculite bed and concrete platform in one pour. Nice job. Did you use rebar in the bed? So what is your next step? I think it is laying down the fire brick oven tile floor--which I understand is laid dry & not mortared? In a fire place the firebrick floor is laid larger than the internal pit & the firebrick sides and and firebrick back are mortared on top. I guess this is to allow expansion of the fire brick hearth without breaking out the sidewalls? & just floats? Are you building a Pompei or Barrel oven? Good luck. Glosta
Reply With Quote
  #6  
Old 05-15-2010, 06:00 AM
Apprentice
 
Join Date: Apr 2010
Location: Chesterfield, VA
Posts: 207
Default Re: Vermiculite mix

I did mine last night. did about 7 1/2 to 1. I was surprised at the amount of water I needed to add.
Reply With Quote
  #7  
Old 05-15-2010, 03:08 PM
jota112233's Avatar
Peasant
 
Join Date: Nov 2009
Location: Cardiff UK
Posts: 30
Default Re: Vermiculite mix

Hi Glosta - yep did use rebar. here's a couple of photo's of how I managed it.









Hope this helps

Jon
Cardiff
Reply With Quote
  #8  
Old 05-21-2010, 10:47 AM
Serf
 
Join Date: May 2010
Location: Northumberland England
Posts: 4
Default Re: Vermiculite mix

Hi Glosta, Finished laying vermiculite mix. Settled for 5:1 mix in the end. Set nice and firm. Now ready for laying oven floor. So many opinions on vaious sites of best way. Some say layer of fine sand some say few blobs of fire mortar under floor and level. which you doing? Anybody else have advice? Dave
__________________
Dave B
Reply With Quote
  #9  
Old 05-21-2010, 11:37 AM
Derkp's Avatar
Apprentice
 
Join Date: Apr 2010
Location: Utah
Posts: 188
Default Re: Vermiculite mix

Jon,

This is Derkp (Derk), I am just at the stage of pouring my hearth slab and have forms set up very similar to yours. Did you have any problems pouring the 1st layer and then adding the vermicrete forms and filling in around them? Any tricks you could suggest?

Thanks
Derk
Reply With Quote
  #10  
Old 05-23-2010, 08:26 AM
Serf
 
Join Date: May 2010
Location: gloucester ma
Posts: 24
Red face Re: Vermiculite mix

I poured a four inch slab with 1/2 inch rebar six inches on center on top of 1/2 inch durarock/concrete board. The extra steel is to compensate for the four foot clear span over the wood storage area and span over the ash pit at the rear of oven. I am going to follow Jota112233/Jon's approach and form the interior insulating bed with 2X4 while leaving a concrete perimeter. Slab was screeded level. Will cut 100+ firebricks in half as preparation for the oven build and retreive the sand for leveling between the insulation layer and firebrick floor. However I wonder if we couldn't just use fine beach sand. The sand in my area, New England is silica dioxide. Although Portland cement volatilizes from the high oven heat, silica sand is melted for glass blowing & should survive the oven heat. The fire bricks are a mixture of silica dioxine and aluminum oxide. I will try to post a few photos later under my user name GLOSTA; but have no success this morning. Good luck. Glosta.
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 hearth question jeffscogson Newbie Forum 14 04-28-2010 01:26 AM
vermiculite mrgweeto Tools, Tips and Techniques 2 07-02-2009 11:52 AM
What is Vermiculite james Getting Started 8 07-09-2008 10:35 AM
Vermiculite - help! Frances Getting Started 7 09-19-2007 04:09 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 05:25 AM.

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