#1  
Old 09-21-2009, 07:54 AM
kebwi's Avatar
Il Pizzaiolo
 
Join Date: Aug 2009
Location: Seattle, WA, USA
Posts: 1,010
Default Vermiculite/perlite confusion

During my initial research I found the super expensive bags of vermiculite and perlite at Lowes. They were in transparent bags so I could see what they looked like and I remember them being gray and rather large in granularity, several mm if I recall.

Then I found a super cheap source of perlite at a masonry store and this morning bought three 4 ft^3 bags without a second thought (I anticipate using five or six eventually). This stuff was much whiter, ivory perhaps. More to the point, it is much finer than the stuff I saw at Lowes. It looks like laundry detergent, grain size of half a mm perhaps? My concern is that smaller grains might pack tighter, leaving less "fluff", less air, and weaker insulation.

Are there different types of perlite and did I get the wrong kind? The bag even lists insulation as a possible application, so that gives me hope.

My final decision for perlite over vermiculite was based on the facts that it is the cheaper of the two and reportedly has a slightly higher insulative R value.

Shouldn't I want something with large grains so it will pack loose with large air pockets? Is this a vermiculite/perlite distinction (which implies that I am not remembering the appearance of the perlite at Lowes accurately) or does perlite come in different grain sizes...and would I be correct in assuming I want the largest grains possible for the loosest fill?

BTW, my application will most likely be concrete, not loose fill, since I'm doing a dome, not an enclosure, although I am considering the approach of a rebar-chicken-wire stucco dome with a dead space around the brick dome and filling it with loose fill as opposed to concrete, haven't decided yet. Obviously, the hearth is concrete either way.

Thanks a lot.
__________________

Website:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

WFO Webpage:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Thread:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Reply With Quote
  #2  
Old 09-21-2009, 12:50 PM
Serf
 
Join Date: Nov 2007
Location: Seattle
Posts: 13
Default Re: Vermiculite/perlite confusion

i found the fine stuff did not create a very good layer, as it became one with the concrete and was not oatmeal-ish enough. So i tore it out. This vermiculite was from McClendon's. The good, coarse grained, setup well, and looked just like oatmeal vermiculite came from DeYoung's in Woodville.
Reply With Quote
  #3  
Old 09-21-2009, 12:56 PM
kebwi's Avatar
Il Pizzaiolo
 
Join Date: Aug 2009
Location: Seattle, WA, USA
Posts: 1,010
Default Re: Vermiculite/perlite confusion

Thanks. Rats. Thought I was set up on this. It was only $15.40 a bag at Salmon Bay in Ballard (pretty near where I live in Lake City).

EDIT: Actually, I just called DeYoungs and their prices are $26.98 vermiculite, $15.98 perlite, so effectively identical to Salmon Bay for perlite.

Thanks again.
__________________

Website:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

WFO Webpage:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Thread:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


Last edited by kebwi; 09-21-2009 at 01:02 PM.
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
Yeast Confusion..what can one say? DimTex Pizza 8 09-16-2009 08:08 PM
FB Board versus vermiculite/perlite rbigante Newbie Forum 10 09-24-2008 05:26 PM
stand size and foundation depth confusion dvonk Newbie Forum 2 04-09-2008 10:11 PM
Refractory Confusion PopPanPizza Newbie Forum 6 10-11-2007 02:39 PM
Mortar Joint Confusion Balty Knowles Pompeii Oven Construction 2 04-30-2007 03:53 PM


All times are GMT -7. The time now is 10:03 PM.

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