Once again, the “in” box on my desk is beginning to fill up with a stack of brochures describing interesting new products.
I’ve selected four products to review in this latest roundup: an insert panel to improve the thermal performance of insulated concrete forms (ICFs); a new wall system for manufactured stone veneer; and two new water-resistive barriers (WRBs).
Polystyrene panels to improve the performance of ICFs
A manufacturer of insulated concrete forms (ICFs), Reward Wall System of Omaha, Nebraska, is now selling polystyrene panels that can be slipped inside of ICFs to improve a wall’s R-value. This product will prove useful, since many ICFs have a relatively low R-value.
Called Boost-R panels, the new foam rectangles come with notches that slide over the ICF form ties and rebar chairs. Of course, these Boost-R panels take up room that would normally be filled with concrete. So if you want to use these insulation inserts, you’ll need to order ICFs with thicker-than-usual cores. If you ordinarily use an ICF with a 6-inch-thick concrete core, and you’d like to insert 4 extra inches of foam on one side of the wall, you’ll need to order ICFs with a 10-inch core.
Boost-R panels are 2 inches thick and are available in several different densities (1, 1.5, and 2 pounds per cubic foot). If you want more than 2 inches of extra insulation, it’s possible to insert two layers of 2-inch thick Boost-R panels inside the core of a thick ICF.
The manufacturer claims that its 1.5 pound/cubic foot polystyrene has an R-value of R-4.17 per inch. That means that a 15-inch ICF with a 10-inch-thick core equipped with a 4-inch-thick Boost-R panel can have an R-value of R-38.
Two-inch-thick Boost-R panels cost between 95¢ and $1.85 per square foot, depending on the foam…
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interesting ICF blocks
ICF inserts are interesting, but I still wish they'd just make the blocks w/ 4" or 6" on the outside and be done w/ it. Inserting blocks and ordering larger ones sounds spendy; I wonder how it compares to screwing or gluing 4" rigid foam onto the outside of a smaller ICF.
new is not always useful
With the exception of windows and mechanical equipment, I'm pretty sure I could cost-effectively build a durable home to Passive House standards using only materials that were available 30 years ago.
ICF R value
Oak Ridge r values are rather outdated, Martin. I am not sure if an R-12 ICF even exists any longer. Average foam forms are from 22-28, with most being right around r24.
Even then it is on the low side compared to the 20,40,60 idea. I am toying with using the forms for the strength, sound and tightness but then furring out the interior with stud and insulating with batts or roxul. its cheaper to furr it out then to add more foam on the exterior of the form. Plus furred walls on the interior eliminates running the electrical in the foam, makes attaching things like cabinets and trim easier, etc. Do this can get your walls mid r30s and push r40.
Have you looked at Quad-Lock ICFs? A local architectural firm is a dealer and used them recently for high R-value walls. They look like one of the better ICF products. They offer multiple configurations of panels and ties to build up to R-84 ICF walls.
How to Superinsulate Your Building
In reference to the Quad-Lock ICFs by Jason
The R-84 ICF walls Jason mentioned are interesting, but what I wonder is are they cost effective? I haven't looked into the cost or construction of these particular systems Jason mentions, but I would think that building an R-84 foundation might be pricy. There is a diminishing return with insulation, and especially so, since foundations are mostly below grade and partly insulated by the ground around it already. With that in mind, is it worth shelling out the extra cash to achieve an R-Value that high?
ICF's with foam only on exterior
TF Forming Systems makes an ICF with the ability to use foam only on the exterior. I think they have up to six inch panels for the exterior.
ICF are not only for foundations. They are typically used for foundations because you typically need concrete anyway, so they are a good way to get a good rvalue below grade. However they are often used above grade but are typically not recommended on this site due to most being around r24, which is considered quite low by most's standards here. Above grade they are strong, quiet, fire resistant, mold, bug and animal resistant, air tight, allows one to have a continuous air barrier and insulation from footer to roof.
You're right. Being more accustomed to most residential applications, that is where my mind immediately jumped
Just an aside - Most buildings subject to USACE Protocol testing specify that all spray-applied liquid air-barriers also be rolled for greater adhesion; I assume this would be true for Enviro-Dri. Many then require ASTM D4541 pull-off/ adhesion testing at 1 dolly per 1000 sq' of surface area.
Rock paper scissors Huber Zip
Rock paper scissors
Huber Zip beats sprayed asphalt IMO.
Just like acrylic tennis and driveway coatings beat the less expensive asphalt emulsions. Asphalt coatings dry out and crumble over time. Never good long term in tennis courts anyway.
Thanks all for the ICF ideas. TF Forming sounds interesting.
HydroGap Caution - Fibercement Compression
The bumps on HydroGap are soft and I've found them to compress when blind-nailing fibercement lap siding. The top corner squashes the gapping material so siding pretty much touches the wrap. This isn't a problem unique to HydroGap - others seem to compress under the top edge of fibercement too.
Most demonstrations of drainging housewraps use a clear flat acrylic sheet that distributes evenly across the housewrap surface which gives a false impression of how each performs beneath various sidings used in the real world.
The logic of Logix
Martin, it would seem Reward Wall has come up with a solution to a problem - their product isn't that great to begin with. I saw Logix at IBS two years ago and was very impressed. It seems the perfect solution for high-mountain builders in our market building in climate zone 7. Most build on sloping sites with ICF crawl spaces. Also a big fan of Nu-Dura because of their collapsible web design. The embodied energy in shipping a truckload of feather-light ICFs is cut in half since they fold flat. Pretty nifty.
Response to Mike Guertin
Thanks for your comments about the compressibility of HydroGap housewrap. I agree with you: if the nubbins are compressed by the siding, they aren't doing any good.
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