#11  
Old 10-09-2011, 08:19 PM
Serf
 
Join Date: Aug 2011
Location: United States
Posts: 15
Default Re: Chimeny, chim chim cher-oo

update: I did an ugly false chimney surround around my 9" x 9" flue. I filled that with a vermicrete mix ( I think it was 10:1). Due to issues of the roof intersecting with some decorative stone shelves, I raised the roof a total of 4.5". This necessitated adding another flue to get the proper height above the roofline. So I bought a 13" x 13" liner and set in over the 9 x 9. It covered about 4" of the top of the smaller one. I used flue cement to join them. I have not finished the rest of the chimney, but had a huge party last night. As I fired up the oven, the damned flue cracked badly. I mean "see the blue sky thru the crack" bad. QUESTION: did it crack because I heated it too fast or because it was not mortared in except for the 4" overlap?
Reply With Quote
  #12  
Old 10-20-2011, 01:27 PM
Serf
 
Join Date: Aug 2011
Location: United States
Posts: 15
Default Re: Chimeny, chim chim cher-oo

Another update: I inserted an 8" steel flue for a wood stove in and resteed it on the 9" x 9" clay flue. I cut it to be about 3/4" higher than the 13"x13' that it is inside of. I then used a 12:1 vermicrete mix between the flue and the 13"x13" outer clay flue. This is the bomb! Even at oven clearing temps the crack showed no increase and the outside of the flue stayed about 120F. Should be less after the water is driven off.
Reply With Quote
  #13  
Old 10-21-2011, 12:54 AM
david s's Avatar
Il Pizzaiolo
 
Join Date: Mar 2007
Location: Townsville, Nth Queensland,Australia
Posts: 4,705
Default Re: Chimeny, chim chim cher-oo

. QUESTION: did it crack because I heated it too fast or because it was not mortared in except for the 4" overlap?[/QUOTE]

By the sound of your description the larger flue was not surrounded by vermicrete. This would mean that when heated there is a big difference in the inside and outside temps. which will create cracking. The insulated flue is more likely to have its temperature more evenly regulated (provided its dry) and therefore should not crack. Your procedure with the inner steel flue sounds like a reasonable solution.
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
chimeny diameter timmarhy Getting Started 7 06-05-2009 07:00 PM


All times are GMT -7. The time now is 06:59 AM.

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