Radiant Barrier Foil

[AR15Texan]

Anyone have experiences with the installation and/or benefits of Radiant Barrier Foil or Radian Barrier Spray on Paint? I was thinking of outfitting the entire attic space before the summer heat sets in.

Also has anyone adding their own blown in insulation? I'm lucky if I have 6" right now. I would like to higer R-value. How do you correspond thickness to R-value?

http://www.blocktheheat.com/radiant.htm

 

[IDASHO]

That spray on looks like a slick idea.

And ANY kind of radiant foil is a good thing.

 

[btmatt]

4 years ago, I replaced the roof on my house in South Texas and installed Tech-Shield decking before the shingles went on. This along with a ridge vent is possibly the best investment I have ever made; Believe the hype, the stuff really works.

 

[dipper]

I used a similar product (Prodex) from insulation4less.com as an exterior wrap on my garage instead of the usual tyvek. It is
claimed to provide an R-14 insulation. I have about 3/4 of a roll leftover and plan to install it in between the rafters on my roof as shown in those pics. I figure it can't
hurt, and I will still use baffles and put in more insulation in the attic in the future and
have proper ventilation.

I had prodex only on the exterior of my garage with no siding and it performed well through a pretty harsh north east winter last year. I am now in the process of getting the siding on but I hope it continues to provide a good radiant barrier. It will only get better when i get the interior walls insulated too.

 

[ni[x]it]

I've almost completed my installation of the foil based radiant barrier (ArmaFoil). I am stapling it to the underside of my rafters. This information is fabulous too, Infact, it looks like those blocktheheat fellas stole most of their information from EES; http://www.energyefficientsolutions.com/rbfoilvspaint.asp
Ps, their shipping is very reasonable!

I bought 4,000 square feet, and will have enough left over to cover my air distribution ducts. I've installed 3,000 square feet so far.

I am now researching soffit venting. I KNOW I do not have enough, and am trying to decide on continuous length soffit venting and standard 4 x 8 soffit registers. You have to ensure that you get that trapped hot air out, or you risk cooking your shingles.

The ideal goal is to get your attic temps to be no more then 10 degrees higher then the ambient outside temps. Currently, on a 90f degree day, my attic thermostat pegs at 160f.

What I can say so far, since summer isnt here in Texas yet, is that the stuff WORKS. While installing it over the past few months, I noticed if I stood underneat where I just covered, the radiant heat was immensly reduced. I dont see how this stuff could not work in reducing your heating and cooling costs.

Also remember that radiant barrier does not provide or directly increase R-value. What it does do is lower the temperature that your insulation sees. (so as a side effect, your attic insulation is more efficient)

 

[CrazyDaddy]

I have been studying this online and have found that the spray paint is not very effective. The foil stapled to the rafters sounds like the way to go. Plus I need to add a ridge vent - any suggestions ?
I am going to do this to my house very soon; yesterday it was 100 degrees !

 

[Ira]

I may try these guys...

http://efficientattic.com/

...for the radiant barrier spray. I already have enough insulation and ventilation.

They have offices in most Texas cities. They are supposedly running a 50% off special on the radiant barrier spray thru the end of June.

Regards,
Ira

 

[ni[x]it]

http://efficientattic.com/
...for the radiant barrier spray. I already have enough insulation and ventilation.

Avoid the spray in stuff...check the research... You can DIY foil, save
money on install, and save MORE money on electricity then foam.

My attic is about 5 degrees higher then ambient outdoor
temperatures with the foil. I went up there yesterday (95degrees outside),
and it was QUITE comfortable (for an attic). And I could totally feel my
soffit vent mods at work!

I've talked to so many neighbors who say they have fantastic ventillation,
when they dont. All they have are two or three vents on the roof, and very
few (if any) in the soffets. These soffet vents are absolutely critical to
getting your hot Texas attic temps in order.

On two sides of my house, I had 5 soffit vents total. Of those 5, two were
not even cut. The other three had marginally small holes, and they were all
covered in insulation. Don't assume you have such great ventillation!!!

I installed 25 vents were there were only 5 originally. I also opened up the
existing holes to quadrupal the effective area. I installed new vents about
every 3'. It wasn't too hard to do, but my overhead working muscles got
worked out!

Sorry for the large pictures...

 

[Ira]

Avoid the spray in stuff...check the research... You can DIY foil, save
money on install, and save MORE money on electricity then foam.

On two sides of my house, I had 5 soffit vents total. Of those 5, two were
not even cut. The other three had marginally small holes, and they were all
covered in insulation. Don't assume you have such great ventillation!!!

The stuff I mentioned isn't foam. It's a paint/coating type of material. It is less efficient than the foil, but certainly easier to install and less expensive. A significant portion of my attic has more than eight feet of headroom, so you would have to use ladders or build scaffolding in the attic to install the foil, whereas the sprayon installer simply uses a longer spray wand. Also, My roofline is all "hip", so it would be very hard to install foil all the way to the exterior edges of the attic/roof. Think laying on your back on ceiling joists in insulation. The total length of my exterior walls is about 280 feet, so there is a lot of hip roofline.

Also, I didn't assume I have great ventilation. I have enough ridge vents to exceed the manufacturer's recommendations for my attic volume and location. My soffits are all made of HardiSoffit panels which have continuous venting, so I have about 280' of soffit vents all around my house. They are not blocked by insulation. Studies have shown that continuous soffit venting (like HardiSoffit or the long vent strips that can be cut into plywood soffits) are much more effective in eliminating "dead spots" in an attic when compared to the type you used.

Ira

 

[ni[x]it]

No sweat Ira.

I have 242'-4" of Soffet/Hip roof myself. I DIY'd the foil install myself.
I cant go with a ridge vent, as there isn't enough length on the ridge to justify it.

Besides, It's all behind me now, so I'm not to concerned about installing a better
product, even tho it's more difficult to install. I figure if you're going to do it, and the
best product is only about $110.oo per 1,000 SqFt, it's still CHEAP considering the
savings.

As far as the soffet vents, the continuous soffet ventilation is much cheaper then the
grills I was forced to purchase. I wasn't willing to retrofit the continuous ventillation
grills when I already had the larger square ones in place. I was very dissapointed with
this, but my hands were pretty well tied by what existed.

 

[CrazyDaddy]

Thanks for the info; I am going to check my soffit vents also. What about ridge vents ?