People often ask me, “How does (insert brand name here) compare to AtticFoil® Radiant Barrier?” As a response, I decided to make this video to compare AtticFoil® with a brand sold in local home improvement stores, ie. Home Depot and Lowes, called Enerflex® Radiant Barrier. There are two main differences between the two that have an impact on your decision of which one to purchase.
I think the differences are pretty clear. Now, tell me which one you’d rather have in your attic?
Hi Ed, here is my plan. Tell me if it is worth doing. I have a cathedral roof with 2×10 rafters. 3″ inches of it is filled by closed cell spray foam. So I have an approximate 7″ gap after the spray foam on the inside of the house. will radiant barrier be effective with this air gap on the inner side of the insulation? The plan is also to install wood pine decking for a ceiling directly against the foil again on the ceiling or inner side of the house. We live in Florida so the goal is to keep heat out.
Thanks
Yes, the two compliment one another very nicely. Foam isn’t going to perform like radiant barrier because just like traditional insulation, foam slows conductive heat gain/loss, it doesn’t stop it. Radiant barrier blocks 97% of radiant heat, meaning it stops it from entering the home. Ideally the foil should be closest to your roof deck, for the primary defense of blocking radiant heat, but it can still work inside the attic, after foam – the question is, how big of a difference it will make? And that is harder to quantify. The whole system combined will make a significant difference in summer heat gain, but how much of that is attributed to the foil layer vs. no foil layer is harder to pin down. If you do decide to go with the foil, make sure you’re using PERFORATED since you opted for closed cell foam.
Hello, I am building a 12′ x 20′ run in lean to shed for my 2 large donkeys. The shed will have 2 x 6 rafters, OSB, purlins and metal roofing.
I am guessing I will need to apply the radiant barrier to the OSB, add the 1 x 4 OR 2 x 4 purlins and then the metal roofing.
I am using the corrugated metal roofing with the old fashioned wave pattern. Would 2 x 4’s be better than 1 x 4’s for air flow?
I do not want nails sticking through the OSB to the underside for safety reasons.
Can the radiant barrier be stapled to the OSB like felt paper? Which version of radiant barrier would you suggest?
Thank you,
Nancy
Nancy,
Yes, this would work great for a shed application. You can staple the foil to the OSB just like felt paper – I recommend the AtticFoil Radiant Barrier House Wrap (click for pricing and sizes) and apply it with the foil side facing UP, toward the sky. Then, add your purlins and then the roof. The difference in a 1×4 versus a 2×4 is small, so I don’t think one would make a significant improvement over the other. Both will provide enough of an air gap for the foil to work, and that will have the biggest impact on the temps inside your shed. You can also add the foil to any walls in the shed that will be catching sunlight from the outside during the day to have a bigger impact overall. More info here: Adding Radiant Barrier to a Shed or Barn
My house is steel frame. I know would have to use screws or slats screwed to the metal, to mount this product. Question is what about moister build up between roof and AtticFoil? Also any other suggestions on how to mount AtticFoil to a steel frame (16guage steel)?
Mounting to metal framing doesn’t have a simple answer. Screws can work, and on this page I have a few other suggestions on my WareHouseFoil.com site: Adding Radiant Barrier to Metal Framing.
As for moisture, it’s going to be largely combated by having plenty of ventilation throughout your attic space. Read more: Attic Ventilation & Moisture Control
Enerflex sells 12 foot rolls also to install like your attic foil rolls across the rafters. They are actually easier to work with that your long rolls.
You need to revise your video and compare their rolls to yours for a fair comparison or it looks like you are deceiving the public.
Jack, thanks for the comment. I’m not deceiving anyone. Yes, they make a roll that is 12′ long. And, yes it is over 3 times the price for getting the same effect as AtticFoil Radiant Barrier So, the point is why pay more for the same effect? As for the 12′ length? I’m guessing you have never actually installed radiant barrier in an attic. Are you not clear that you CAN cut AtticFoil to any length you want? Plus, you will want a product that can easily bend/wrap and be able to cut around supports, strongbacks, vent pipes, electrical etc.
Ed,
I live in Phoenix, Arizona and my home has a tile roof. The roof has a 30 lb tar paper underlayment under the tile which is badly degraded. I plan on having the tiles removed to replace the tar paper with a new product that is supposed to have a 40 year warrantee. I would like to install Radiant barrier underneath of it. What is the life expectancy of Radiant Barrier. I am open for ideas!
Chuck Linden
Yes, the RoofingFoil.com underlayment product will be perfect for this application. These products come with a formal warranty but there’s no reason that under normal wear-and-tear they couldn’t last as long or longer than the roof itself.
Ed,
Question is for a traditional all metal shop in east Texas
R-panel roof, 8″ purlins
I plan on doing the banding system roof which will use 8″ vinyl backed fiberglass between the purlins.
My question is, to stop the radiant heat from heating the fiberglass would your foil radiant barrier (no foam) on top of the purlins with a 3/4″ airgap between it and the roof sheets be more beneficial than just the radiant barrier that is on the inside of the vinyl backed fiberglass?
Yes, the overall performance would be more efficient because you’d be blocking that heat closer to the source where it enters the shop instead of letting it absorb farther in. When it’s possible, it’s always best to have foil as close to your outermost layer in the structure (in this case, the metal R-panels) with the minimum air gap.