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Deckorators Voyage decking, which is mineral-based rather than made of a plastic or wood composite, is lightweight and doesn't expand and contract as much as standard composite decking.
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"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
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For what purpose?
William the Geezer, the sequel to Billy the Kid - Shoe
Friend sent me the link as he's thinking about getting involved with the product in Florida.
Seems to be mostly for heat reflective properties I would think then.
Remembering the reflective foil guy who use to post his spam here years back claiming all sorts of stuff.
In general they are only useful where you have solar energy impinging, ie a roof, and where you have one side open.And most effective in the souther states.But they are often oversold. The one I like the best is the stuff that is sold for insulation under slabs..
William the Geezer, the sequel to Billy the Kid - Shoe
I've installed radiant barrier roof sheathing in a few energy star houses I've built. The energy star program rates various upgrades on kinda a point system, which is based on % of energy usage reduction for the particular upgrade. Radiant barrier sheathing is an excellent value - based on energy usage vs price. Obviously they are more effective in the "sun belt".
If you google, I think it was the U of FLA that did a bunch of research on them.
Yes, he mentioned them being used in the Energy Star program.
I think he's trying to tempt me to move to Florida for the winters.
Doesn't sound like a bad idear. snorK*
Well, the divil is in the details as the old adage goes.
Radiant foil works like putting Al foil on a cookie sheet to make nachos. Pull the nachos out of a 350º oven after 20 minutes, and you can grab the foil between your fingers, but you want a mitt or a towel to grab the cookie sheet.
The foil-faced sheathing has some effect (more in labroatories) in not "emitting" heat into an attic from a hot roof deck. Tricky part there, though, is that the deck is still hot, and is in very firm contact to the rafters, and thence into the rest of the framing.
If you are in 80-90 day a/c country, you probably get more effect from the low-emissive sheathing than down here in 180-190 day a/c land. Hear near 30ºN, the mass of the roof is the enemy. Sun hits it for more than 12 hours a day, every day in the summer half of between the equinoxes. Boatloads of btuh every day.
On spacers over galvanized rafters or trusses, that might be right spiffy in my climate. But a couple-four inches of rigid over the deck with metal roofing over that winds up being a bit easier, and more readily "accepted" as trade practice.
>> But a couple-four inches of rigid over the deck with metal roofing over that winds up being a bit easier, and more readily "accepted" as trade practice. <<
So, that would be for a "sealed" attic? ie - unvented?
So, that would be for a "sealed" attic? ie - unvented?
Well, it could be--in my climate it can make a lot of sense, but, you could still vent the attic. Not having that mass of solar-heated roofing and deck and rafters will keep attic temps down. To the point that natrual ventilation might could keep up.
Now, I rather like moving the insulation plane out to the roof so that the duct work and AHU are working in more-conditioned spaces. Now, I'm also not a fan of the 10/12 and 12/12 roofs the plan shops are cranking out lately. All that happens with those is you get a circus tent close to the same volume as the conditioned space in the house below--a complete waste in my book.Occupational hazard of my occupation not being around (sorry Bubba)
I used it...his office and plant were around the corner from my shop. Bought it directly from him and tacked it to the underside of the top chord of the trusses on the house I built for myself. I built plenty of HVAC duct systems in Florida attics and this is one product that would keep the temperatures reasonable if the attic was vented correctly.
It was a easy install during new construction.
rez,
I use radiant barrier from http://www.radiantbarrier.com in Arlington, TX.
Heavy duty enough you can't tear it. I'm stapling it on the rafters and didn't get it done before the heat hit.
Where I had the barrier installed a thermal thermometer read 78 and in the area 6' away, it was 98.
Since it's only about half done it really doesn't do any good yet.
Pete
Plano, TX
I REALLY liked the pix on the top of the link.
3 'workers'
White t-shirt, nary a smudge on it
Perfectly clean floor.
Yard outside, not a single cutoff or cardboard box
Not a tool in sight
Oh yeah, the super did not have safety glasses <G>
etc..
I had this http://www.radiantbarrier.com installed in June of this year
We had the coolest July on record so I can't tell yet of the effectiveness
We have had several 90+ days so far this month and it appears that the house is staying much cooler than it used to
This winter will be the true test
I used osb with a radiant barrier on my roof deck 2.5 years ago and in south GA I can get in my attic on a 98 degree day I not die of heat stroke.I can also tell that last month my elec bill was $147.00 with 2400 sq feet in the middle of a hayfield with no trees and an indoor temp of 76 degrees and 50% humidity with a well pump on the same meter as the house.
>> This winter will be the true test <<
How do you figure? Are they supposed to reflect heat back into the house during heating seasons?
Yes that is the theoryAlso the radiant is sealed all around to help stop hot air from going upWe will see
I'd be interested to hear the result.
Edited 8/15/2009 10:33 am ET by Matt
I will try to keep ya postedMay need a reminder
There was be as much temp difference for it to a large affect during cooling..
William the Geezer, the sequel to Billy the Kid - Shoe
"There was be as much temp difference for it to a large affect during cooling"Sorry Bill, not getting the just of this oneRephrase?
... or the jist for that matter. :)
thanksI was only 1 key off
"There was be as much temp difference for it to a large affect during cooling"I kept rephrasing it in my mind as I was type. It should that there is not as much temperature differences between the interior space and the roof so that the amount of radiant energy transfer Every hot body (in the physics meaning) radiates radiant energy. And every body receivies radiant energy.A body will radiate more if it has a high emissivity and receive less if has a low reflectivity.The amount of energy involved is based on the absolute tempature.The closer to bodies are in absolute temp the less NET radiant energy transfer there is between them..
William the Geezer, the sequel to Billy the Kid - Shoe
OkDoes that mean that it will be less effective during the winter reflecting heat back towards the living area than it is at reflecting heat back towards the roof during the summer?
Yes..
William the Geezer, the sequel to Billy the Kid - Shoe
ThanksThat does make since to meWe had it installed mainly for the summer heat issuesIf it helps some with the heating season that would be greatWe will try to remember to post what we gainWeather has been very humid and in the low 90's last 2 daysHouse very comfortable using only 1 large window a/c unitLast year we ran a 2nd unit for the bedroom area
Here is some hopefully unbiased materials for anyone to read who is interested in radiant barriers:
http://www.fsec.ucf.edu/en/publications/html/FSEC-EN-15/
A little dated: http://www.fsec.ucf.edu/en/publications/html/FSEC-CR-1231-01/index.htm
My 2 cents: radiant barriers work ... proven in the laboratory ... WHEN there is an air space adjacent it.
Remember, for the radiant barrier to work it must be clean. Most applications outside the laboratory are far from clean. Even sloped attic rafters will get dirty. So in spite of just installed performance being 'stellar', their long term performance may not be so well known. If it is inexpensive (no/low cost), fine, no big deal. But if your friend is out to make big bucks installing fancy products that tend to be expensive (relatively speaking), then I think it's a mistake.
The key is proper application. The problem is much of this product tends to be oversold to anyone and for any application. Sold for the right applications, any product has a place. Just because something works for insulation for the Space Shuttle doesn't mean the same thing works for our houses. I just saw a presentation for ceramic coatings and the guy made it sound like it was the best thing since sliced bread for ALL applications ... cars, RVs, Houses, Warehouses, Trailers, commercial buildings, etc. etc.
My advice ... learn VERY WELL the application and the technology BEFORE investing in it ... know the proper applications where it will be most effective. Only then get involved or use it.
The link (although I didn't look at it exhaustively), didn't seem to have many details about the specific way(s) it should be applied. Seemed like lots of products, but not much detail about how it is properly used. Leaves me wondering a bit. If the company tells your friend that it is 'good for everything and everywhere', your friend should be cautious.