I'm going to resurrect this one.
It's damned hot here in Central Texas and I bought radiant barrier
sheeting to install in the attic. Problem is, I can't get to most of
the places where it would need to go. Why not install it ON TOP OF
THE SHINGLES? It would be kind of temporary but, to get us through
the summer, seems like it would be a good idea. I was thinking of
Styrofoam sheets that I could staple the sheeting to and then install
these on the roof with some space between them and the shingles. I
don't mind crawling around on the roof but I can't get myself in all
the attic spaces.
Also, I Googled radiant barrier paint and sure enough there is such a
thing. I was thinking of repainting the outside of my house.
In reality, all this would go on the back. The front has nice big
shade trees and it's very protected.
Was toying with the idea of installing a sprinkler system on the roof
to cool it down during the day...?
Brad
On Jun 16, 2:02*pm,
(neutralexistence) wrote:
neutralexistence had written this in response tohttp://www.thestuccocompany.com/maintenance/Let-s-talk-radiant-Barrie...
*:
Bob-tx wrote:
I have been reading about everything I can find onradiantbarriers,
but still have a few questions and concerns.
I am not talking new construction here, whereradiantbarrier can be
installed under the roof sheeting. *I am talking about existing
homes, and then, primarily the spray on type.
Here is what I think I understand - -
Sprayed onradiantbarrier will cut down 65 to 75 percent of the
sun's radiation, - but I really don't know how much cooler that
makes the attic.
Sprayed onradiantbarrier effectiveness depends primarily on the
people who do the work. *They can thin out the paint so it is much
less effective, they can spray it on to thin as well, and not get
the complete underside of the roof. *Most homeowners would never
know they didn't get a good job. *This is a major concern.
Dust on aradiantbarrier surface decreases its effectiveness - the
more dust, the less effective. *Although there generally is not a
lot of dust floating around in most attics, it can be stirred up
easily. *For example, adding more insulation is a dusty procedure,
and if there is a previously installedradiantbarrier, you will
decrease its effectiveness - to some varying extent.
There is a company that advertisesradiantbarriers for half price
(whatever that is) and free added insulation. *If they spray their
cheapradiantbarrier (about which I would have concern about how it
was mixed/thinned) and then add the insulation - instant dust.
This company has been advertising for months with some fantastic
deal or other and will only quote prices through an in home
salesman. *I smell high pressure here.
Has anyone used this company? * *Has anyone used other companies to
spray aradiantbarrier, and how satisfied are you?
I know I am asking a lot of questions, but I sure don't relish the
idea of getting ripped off. * Thanks,
Bob-tx
Hey Bob,
Let me see if I can shed some light on the questions. First of all the
paint typeradiantbarriers(term used loosely) have a "reflectivity" of no
more than 75% which "technically" is not, by definition, aradiant
barrier. Aradiantbarrier, technically defined, will have a reflectivity
of at least 95%.
I highly recommend a foil sheet type a
href="http://www.raflect.com"radiantbarrier/a with a reflectivity
value of 97% to 98%. While the installation is a bit more challenging, the
results will be much better.
To address you question about dust andradiantbarriers. While it is true
that dust can degrade the effectiveness of aradiantbarrier, by
purchasing a double sidedradiantbarrier, you eliminate this problem.
Also, even if you do have some dust on the single sidedradiantbarrier,
it is still more effective then the paint typeradiantbarriers.
As far as installation, I highly recommend stapling theradiantbarrier to
the bottom of your roof rafters. This will leave a gap (usually 5-1/2")
for air to move from your soffit vents up to your ridge vent, effectively
moving the hot reflected air up and out of your attic causing your whole
attic to be cooler.
Cooler attic means lower strain on your HVAC system causing lower energy
bills.
I also recommend getting a perforated typeradiantbarrier so you do not
run the risk of any condensation issues which could lead to structure rot
and/or mold.
Anyway, if you have any other questions let me know.
Adam
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