Bob,

Let us know if you find a supplier for Foamglass.

Bob I,

You may already know about this link:   http://www.foamglas.us/building/contact/

It appears that Pittsburgh Corning Corp. may be either producing or selling foamglass which is also known as cellular glass.

Bob I,

Thanks for the info.  That is interesting.  Now we have a way to insulate concrete walls and under slabs that should be accepted by the codes.  At least, I doubt termites will nest in this material like EPS.

Posted By jonr on 14 Apr 2011 09:17 AM
http://www.croplifefoundation.org/upload/su%202003%20termites.pdf

That's certainly encouraging, but like the "built-in job security clause" of most research studies, it recommends further research is needed:

The results demonstrated that 1,000ppm deltamethrin provided signiÞcant protection off oam board insulation against both R. flavipes and C. formosanus. Further studies are needed to determine the longevity ofdeltamethrin- treated foam boards against termite damage when installed below grade on structure walls.

My concern is that with a floating slab design, the short piece of foam up the inside of the basement wall at the edge of the slab leaves a direct path for them, should it not work, or the pesticide breaks down/leaches out over time.  I'd have built a "super-highway" for termites...

When so many places prohibit foam below grade, without differentiation of whether it is impregnated with a repellant/pesticide or not, it certainly causes concern...

Perhaps a "hybrid approach" of of the less-expensive BlueGuard underneath the slab, and FoamGlas as that perimeter thermal break in the slab would work...

Continuing to research this, especially given light of studies on the effectiveness of BlueGuard in other topics here...

I just reviewed the new Building Science publication RR-105, Building America Special Research Project:  High R-Value Enclosures for High Performance Residential Buildings in All Climate Zones. dated 1 Feb 11... http://www.buildingscience.com/docu...ew

I found a couple of foundation details really interesting:

1.  None of the foundation details shown for any climate zone showed exterior insulation.  It was all on the interior... this is somewhat counter to my ideas of basement wall mass as part of my passive solar mass.  If all the concrete is outside the insulation layer, it would seem to be functioning like a huge heat-sink, and have no value as solar mass...

2.  All the foundation details shown (all climate zones), show a continuous layer of 2" XPS that laps over the foundation, joining another layer of 2" XPS on the interior basement walls.  Then, additional insulation is added on the interior for colder zones.  There is no identification, provision, nor discussion of any type of termite barrier in the creation of this insulated floating slab.

This brings up a couple of questions that I'd like more insight on:

1.   I'm thinking of using 2" of BlueGuard on the outside basement wall, coated with Tuff II, and 2" of EPS on the interior, studded out.    This should give R-20 (the level recommended for Zone 4.  What are the shortcomings of this approach?

2.  If I use BlueGuard underneath the slab also, as I currently plan,  I'm considering using it on the bottom edge of the vertical interior walls, so that there is no easy avenue for termite entry -- perhaps a 6" strip, so that the insulation under the basement floor butts up against it, leaving 4" exposed matching the pour of the slab.   I also thought of using a 2" piece of "L-shaped" aluminum flashing over the top edge of the BlueGuard whose side flange would get encased in concrete, while covering the top of the BlueGuard.   That would be final termite barrier preventing entry, block off the BlueGuard's additional insecticide from the living space, and perhaps serve some value as a screed board when the slab is poured.  Then, insulate the interior wall above that using typical XPS, studded out procedures.  Is this pure overkill, or a prudent minor investment -- since the long-term strength and effectiveness of BlueGuard can't be determined at this time?

3.  Finally, since I need to install footer pads/piers to support two load-bearing center posts and a masonry chimney, my current thoughts are to use no insulation at all on or around them.  Though there would be some thermal bridging to the subsoil, there's no easy way to prevent that I can see.  I want  the masonry chimney structure to be a part of my thermal mass, so it needs all the contact with the slab that it can have, IMO.  I could try to insulate between the slab and the pads for the posts, other than where the posts would be supported, but is it worth it to add the complication?  Am I thinking straight here, or am I missing something?  

TIA...

Posted By Bob I on 02 May 2011 05:43 PM
from the Dow website:
Is STYROFOAM BLUEGUARD insulation insect proof?
Answer ID 5966 | Updated 01/01/2010 02:29 AM
Is STYROFOAM BLUEGUARD insulation insect proof?
STYROFOAM BLUEGUARD insulation is NOT insect proof.

Under the footings, consider Corning Foamglas: www.foamglas.com