Original AtticFoil® is an amazing product – it blocks over 97% of radiant heat, it’s tear-proof and it is heavyweight and easy to use. Many of our customers install the foil by stapling it up under the roof rafters, creating a sort of ceiling. This is most common in Souther states where air conditioning ductwork is typically installed in the attic. This method is great for reducing radiant heat gain into the attic in hot climates.
However, we also have many customers in cold or mixed climates that were looking for benefits from our foil both in the hot summer and the cold winter. The solution to a climate zone like this is to lay the foil on top of the insulation (as long as the attic space doesn’t have any HVAC components or tons of storage, otherwise a hybrid method would be best). The over-insulation install method allows the foil to still block radiant heat coming off the roof in the hot months but it also keeps the insulation warm in the cold months, making the home stay more comfortable and energy efficient.
Although the original AtticFoil® does a great job of allowing moisture to pass through its micro-perforations, there are some circumstances where the moisture level could be exceptionally high and water could get trapped. Keep in mind that this is a rare occurrence; however, the FEAR of trapping moisture has caused many people to be hesitant about installing a radiant barrier directly over their insulation in cold or mixed climates. SuperPerf™ is a customer driven product; we had many customers tell us, “I want to install a radiant barrier, but how will I KNOW it won’t trap moisture?” Unfortunately, every home and circumstance is different and we just couldn’t make that promise with our original product.
With that in mind, we developed an exclusive foil barrier product that not only offers the same reflectivity (97%) as our original foil, but it also offers the added peace of mind of not trapping moisture. We call this product SuperPerf™ because it has larger perforations than our original.
Whereas the original AtticFoil® is micro-perforated (done with tiny pin-holes – seen on the left of this photo), the SuperPerf™ is punch-perforated, meaning an actual piece of the foil (quite small) is punched out and removed (seen on the right side of the photo). This is just like the idea of using a tiny hole-punch on a piece of paper. The result is an extremely breathable radiant barrier foil that still offers you great coverage and protection from radiant heat gain/loss.
If moisture concerns were keeping you from looking more seriously in to adding a radiant barrier on top of your existing attic insulation, I encourage you to give the new SuperPerf™ a try. I’m confident you’ll feel good about using a product that was specifically designed with cold climates in mind by a trusted leader in the radiant barrier industry. If you have any questions about the new SuperPerf™ or if you’d like to get your hands on a sample of it, feel free to contact us or request our sample packet online.
If you have a special application or project in mind and want some advice on how to incorporate a radiant barrier – send me an email! Until then, stay comfortable out there…
I have been researching all options from foam closed cell-open cell to foam board to radiant barriers. I have come up with the ideal of wrapping a heavy duty 1/16 cardboard with radiant foil and placing it 3″ bellow my roofline to see any added benefits. I do realize this sounds a little absurd but I’m hoping to accomplish three things, first I will have about 3 inches for my heat to escape, second if this doesn’t help enough I will have a barrier already in place and a support to spray closed cell 2″ I think to turn my attic into a conditioned area, third cardboard is free at my work. I guess I am looking to see if I am missing something or am I just being to cheap? can you help and should I use perforated of solid radiant foil..thanks carlos
Carlos, sounds good to me. 3″ airspace is way more than you need. I’d go 3/4″ or 1″ and max out the foam. I’d use perforated if you use open cell foam and solid if you use closed cell foam. The only thing I’d warn you though, is there can be some unintended consequences when converting an existing home to a sealed conditioned space. First, if you have a gas/propane furnace, you must build a “room” and keep it outside the space and have multiple carbon monoxide detectors both audible and visual. Second, your AC Load can drop SO much that short cycling and moisture problems can occur because the unit may be significantly oversized now. I love foam closed attics for new construction where I can design the AC system to match the load, but on existing homes it can get tricky.
Hi Fritz, what I’m thinking about is putting reflective barrier over tar paper over existing shingles before laying down purlins and then 5v crimp metal for my roof-over. I don’t see anyone doing this particular combination, and I wonder why not? I thought the tar paper will prevent any moisture, and the foil will give me the reflection I want. What do YOU think?
This is a great idea and I cover it here on our RoofingFoil.com website. http://www.RoofingFoil.com Also, there are multiple videos showing different install methods. There are many high-end roofing companies using Radiant Barrier under different roofing systems as long as it has the required air space. You can either use felt and the single sided foil as you mentioned or look at our new product that is both an premium synthetic roofing underlayment AND radiant barrier in one. It’s even Miami-Dade County approved to be used under metal roofs in Hurricane areas. Miami-Dade County Approved Radiant Barrier Roofing Underlayment Video Here: https://youtu.be/YQh3u44aNgo