Anybody got a brand name for this stuff or know of a reliable west coast (USA) retailer who sells it?
I've looked at our local Home Depot and Lowe's outlets and found only the 1/2" thick variety with the poly sheathing which I'm told is meant only for waterproofing basements.
There are two types and they are effectively the same. The pink variaty is made by Owens Corning. Owens Corning also makes 'pink' fiber glass insulation as well. Other companies make natural color (yellowish) fiber glass insulation. (Pink is Owens Corning's trademark color: think Pink Panther, who is their spokescartoon.) The blue colored foam is made by various other companies (Dow comes to mind as one). Both colors are same dense insulation foam. If it is not available at Home Depot or Lowe's, it should be available at 'conventual' lumber yards. I'm guessing you are in a 'warm' area, where insulation against winter cold is not a major issue, which might be an issue in terms of what is stocked locally.
Google Image Search:
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Pink Foam (Owens Corning):
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Blue Foam (Dow):
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Here is some additional info:
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What you want is the Extruded polystyrene (XPS), which comes in Pink (Owens Corning) or blue (Dow).
Yes, but, lots of do-it-yourselfers in warm areas don't always get it, so Home Depot, et. al. might not stock it. Which is why I suggested a lumberyard. Also, the foam is often used around masonary foundations which may or may not be typical in some areas, which again is a local 'preference' issue and might have to do with local geology issues -- eg water tables, soil / ground formation issues, etc. Also insulating
*basements* is a different issue from insulating above ground areas. Above ground, spun glass insulation or blown in insulation might be more typical for example.
(The availablity of foam insulation in certain places has come up here before.)
Those are _minimum_ R-values based on cheap energy. They ignore the real increase in energy prices. IOW, they are too low. My rule of thumb is: double the minimum recommended R value. That's what I did when we built our house 31 years ago. I figure I recovered the cost of additional insulation within two years. And since then recommended minimums have increased, so that I now have a house insulated to the current minimum standards.
Here's updated information on recommended R-values:
True, but the effectiveness of a given R-value is a function of the DIFFERENCE in temperature between the two zones. The rate that heat moves from a hot zone to a cold zone is proportional to the SQUARE of their difference in temperature. If you double the difference in temperature, you need FOUR times the R-value to heat or cool the space you want to control with a similar amount of energy (roughly speaking).
If you want to keep a place at 72F/22C when it is 100F/38C outside, there is a temperature differential of 28F/16C to insulate against.
That is a far cry different from needing to keep a place at 70F/21C when it is 20F/-7C outside. This is a 50F/28C differential.
True, but insulation is cheap. Question: where do you put discretionary dollars when building or renovating a house? Granite counter top? Or higher R-value insulation? The incremental cost of higher R-value is a good deal less than the square of the R-value difference. IOW, it's very low when building, and still quite low when re-siding or re-roofing. So you have more R-value than you "need"? Ok, but so what? Every little bit helps. In the long run, you'll save loadsadough. Keep in mind that the price of energy will go up. It will dip down now and then, but the trend is up and up and up.
And it's not just R-value that counts. So does colour. Data-point: When we had to replace the dark brown shingles, we went to the palest grey we could find. Reduced the ambient temp in the upstairs rooms by about
5C/9F. Amazing. ;-) (We have a cathedral ceilings, probably the worst type for heat retention/rejection).
Anecdotal evidence from people who've built houses using odd-ball technology, such as 2ft thick straw bales, impregnated with cement slurry for fire resistance: heating/cooling costs on the order of 10% or less that of a conventional house.
Final observation: we tend to fixate on purchase price (PP), not total cost of ownership (TCO). Printer mfrs (for example) exploit this bias.
Or when it is 110/40 in the shade "and a good thing we're not in the shade." I use to wonder about wool robes in the desert, till I realized that 98.6 (36.8) inside - 120 plus outside, wool makes for a wonderful insulator.
I totally agree that added R-value is great, and I have done this in constructing my own home.
Of course, there is a law of diminishing returns at play here - the first "R" has the most effect and each additional "R" added provides slightly less effect than the previous one. There is also the matter of some situations, such as within walls, have a maximum capacity unless additional framing (with it's costs) is added, or unless a material with a higher R-value per thickness unit is used (the foam board of this discussion has about 5 per inch, while fiberglass has about 3.6 and rockwool has about 4).
I was merely pointing out why the standards vary from one location to the next, which was an early question on this topic.
And in turn directly relates to what sorts of isulation is availble in various locations. Getting 2" foam isulation from the local Home Depot is trivial here is New England, but is likely to be harder in warmer areas, where 2" foam isulation *might* be considered 'overkill' or where local construction practices would not use foam isulation at all. Foam isulation is most *commonly* used over concrete basement walls (either inside or outside). In parts of the country where concrete basements are uncommon (either because high water tables (Florida) preclude basements or because of local geology prevents digging cellar holes, etc.), *foam* isulation might be harder to get.
At the start of this thread, the OP was having a hard time finding foam isulation in a useful thickness and noted that it was not available at the local Home Depot and wanted to know about different types and where he might get some.
I live in Redlands, MIke -about 65 miles east of lovely downtown Burbank- and I've discovered that I can special order the pink stuff from Home Despot, so the guys in our club are working up a collective order right now.
Sure, the peak difference between 120 and 75 is 45F, while my example was
50F. However, I don't know of too many cold climate zones where the difference changes by 25F as "120 dropping to mid 90s at night" does.
Not that such swings never exist, but few places that are 20F at night rise to the mid-40s on any regular basis. Colder climates tend to have greater SUSTAINED differences than hotter climates.
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