Old 07-25-2012, 05:52 AM
Join Date: Apr 2012
Location: maine
Posts: 9
Default Render question

I have read the archived posts on stucco and render but still have a few questions. Thanks for any help.

I have a bunch more firings before I put the 2 render coats on my vermicrete layer. The vermicrete has formed some large expansion cracks that open and close with temp changes. I plan on using surface bonding cement with the liquid additive to form the stucco layer which I will later paint with stucco masonry paint.

I read that you would first fill in the cracks with SBC before the first layer goes on. If I cover the cracks when the oven is cool, I don't understand how the cracks won't bust through the stucco layers when heated up. How do you handle the expansion cracks so they don't crack the stucco?

Also, how long should you wait after the first coat before putting the finishing stucco coat on the oven?
Reply With Quote
Old 07-25-2012, 06:21 PM
david s's Avatar
Il Pizzaiolo
Join Date: Mar 2007
Location: Townsville, Nth Queensland,Australia
Posts: 5,156
Default Re: Render question

Don't worry about the vermicrete layer cracks. The layer is not structural. The only reason to add cement, and therefore water is so the stuff will stand up vertically on its own. If adding vermicrete to an enclosure style oven it is better to add the vermiculite dry. The problem you now have is that you have to eliminate the water otherwise the steam pressure can crack the outer stucco.the dryly vermicrete is slightly elastic anyway so won't cause a problem so long as it's dry. Try placing some plastic sheet when firing, over the vermicrete to test if water condenses under it to test if all the water is eliminated from the vermicrete.
Reply With Quote
Old 07-25-2012, 07:05 PM
Join Date: Apr 2012
Location: maine
Posts: 9
Default Re: Render question

Thank you David, but even if the vermicrete layer is dried out, won't the cracks that already exist continue to expand and contract as the oven is fired? If the cracks go up and down based on when the oven is hot/cold, then how do you prevent the stucco layer from cracking also?
Reply With Quote
Old 07-25-2012, 07:26 PM
Tscarborough's Avatar
Il Pizzaiolo
Join Date: Oct 2009
Location: Ausitn
Posts: 3,292
Default Re: Render question

As he said, the vermicrete is not structural, i.e. it will not mirror through the render/stucco. Do not fill the cracks with SBC (that is for structural, non thermal crack repair), fill them with either loose vermiculite or a very high ratio vermicrete (like 8 or 10 to 1).

Last edited by Tscarborough; 07-25-2012 at 07:29 PM.
Reply With Quote
Old 07-26-2012, 08:07 AM
Join Date: Apr 2012
Location: maine
Posts: 9
Default Re: Render question

I understand now, Thanks
Reply With Quote

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
Breathable stucco render? waynespizzaworld Design Styles, Chimneys and Finish 1 04-22-2012 10:01 AM
Cement render over chicken mesh ravenja Getting Started 3 09-28-2011 03:38 AM
Cement Render (Stucco) Question Alter ego Tools, Tips and Techniques 7 05-06-2010 01:27 PM
Acrylic Render question THX1138 Tools, Tips and Techniques 14 04-11-2009 07:33 PM
Question on Pizza Oven Found in Warehouse fred.collins Newbie Forum 5 10-20-2008 09:22 AM

All times are GMT -7. The time now is 10:09 AM.

Powered by vBulletin® Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
2006/10 Forno Bravo, LLC