Structural Insulate Panels to build home

[Eric Chapman]

Any opinions, good or bad about using structural insulated panels (sips) to frame up a house?

[racefan0309]

Does anyone have any opinions, good or bad, or general advice about using structural insulated panels (sips) to frame up a house?

[hallerb]

saw it on this old house, looked good. if water gets to anything built of chip board rot is instant result.

but if your in a storm prone area, hurricanes or tornadoes a concrete home is likely a far better alternative

basically withstand a 300 MPH wind, looks like a regular home, very quiet and energy efficent, insulation buried in concrete

[Edwin Pawlowski]

I like the ICF systems better myself, but both are good.

Check out

You'll have a solid house that can withstand hurricanes, minimal tornado damage, and saves a bundle on energy.

[nicksanspam]

SIPs save a lot more, once we discount lies about ICF dynamic R-values...

On a day with average exterior temp T, a 68 F concrete house with 2" R10 Styrofoam walls will lose or gain about |68-T|/R10 Btu/h. With min and max temps Tmin and Tmax, a frame house in the same location with walls with an equivalent R-value might lose (68-Tmin)/R all night and gain (Tmax-68)/R all day, with an equivalent dynamic R-value of 5(Tmax-Tmin)/|68-T|.

Here is a list of US locations and dynamic R-values, based on NREL data:

location month Tmin T Tmax dynamic R-value

Philadelphia June 61.8 71.8 81.7 26.2 Phoenix, AZ April 55.3 69.9 84.5 76.8 Flagstaff July 50.5 66.3 81.9 92.3 Prescott June 49.9 67.2 84.5 216.3 Albuquerque September 55.2 68.6 81.9 222.5 San Diego October 60.9 67.7 74.6 228.3 Houston April 58.1 68.3 78.4 338.3 Ely, NV July 48.0 67.5 87.0 390.0 Colorado Springs August 55.2 68.3 81.3 435.0 Las Vegas October 54.3 68.3 82.1 463.3 Elkins, WV August 56.2 67.8 79.3 577.5 Bakersfield October 54.8 67.8 80.7 647.5 Rock Springs, WY July 52.8 68.0 83.1 infinite!

Nick

[Edwin Pawlowski]

Since about every ICF has 5" of foam, why not use the actual numbers for your comparisons. Looks like you'd rather juggle the numbers to show the result you want.

[John Grabowski]

A customer of mine used that type of construction for parts of his house. It has excellcent insulation qualities. He told me that he feels as though he paid twice for the house because the interior had to be framed out to allow room for the utilities to be installed.

[racefan0309]

The insulated panels I am looking into have 3 1/2" of polyurethane foam insulation for the walls, and the roof panels are 5 1/2" thick with 7/16" osb bonded to both sides. the r-value of the foam is close to 7 per inch. So they say the walls are r-28 and the ceiling panels are r-40. But since there is some framinig inside the foam for window support, I would think that would affect the overall r-value of the wall. I've read on numerous web sites of companies that make them about how much strong they are compared to conventional stick framing, and how you can save huge amounts on utilities, some claim

50-70%...But one of my big concerns is if they are going to stand the test of time? Is there any concern that the bond between the foam and the osb will ever seperate? What if you get termites in the foam? Also, I read a report from the Dept. of Energy saying that people save around 15% on utilities, which is a long way from 50-70% the makers of the product claim. I would appreciate any futher comments/ opinions...thanks

[racefan0309]

inside the foam for all of your electrical, phone and cable needs. (so you need an exact electrical plan). And since there is typically no plumbing installed on the exterior walls, there should be no need to frame around the panels.

[dpb]

I don't believe termites and foam are an issue. The OSB and water would be a bad mix so maintenance of the exterior would be important. But, then again, it's important for conventional housing as well. Only some actual time/experience w/ these newer concepts will really tell how well they hold up for the long haul so there's a little bit of risk there, perhaps.

Of course there's some effect around windows and doors but if they're well designed and air-tight they're as good or better as anything going and unless you're going to do without, there's no alternative. But, the overall R-factor for the entire wall/house isn't that of the wall/roof material itself, certainly.

I'd look at the DOE report carefully and see that it is comparing equivalent structures to what you're looking at. If it appears to be, then I'd ask for more technical and detailed data from the manufacturer to at least see if they have what would appear to be rational explanations. Of course, one would expect claims from a manufacturer to be at the high end of what could possibly be justified while the DOE report may not even be a very similar construction...

[nicksanspam]

Good idea. You might suggest that to Polysteel :-)

Nick

[Chris Friesen]

I wish. My house has supply and sewer piping on the outside wall of the utility room. Made it a pain to insulate that wall.

Chris