We build home is Austin, Texas and have been using a radiant barrier in our homes for well over fifteen years. The barrier that we use is factory applied to the underside of the roof decking.
We have never had an issue with the shingles.

We install radiant barriers on all of our houses. We have never had a problem. It lowers HVAC operating expenses significantly. We buy the foil factory installed on the underside of the plywood. We started by using the foil on the under side of the rafters. There were always some gaps, but it also lowered operating costs significantly. That cost about $1,000. Now it only costs about $225-250. It is a great, easy way to lower your operating costs.

I'm a professionaly licensed real estate inspector with over 2500 residential home inspections performed in Texas. Bottom Line - Radiant Barrier Technology works.

I know that when I pull the drop down attic ladder and see the reflective material, that attic will be 20-25 dg F cooler than an attic with out it. In Texas, 100 dg days are common, and the typical attic temp without radiant barrier will hoover between 115 to as mutch as 150 dg F. In the DFW area, the hottest I've ever red tagged was 153 dg F!

Of course you can't rely on radiant barrier technoogy alone to lower attic temps. Most homes do not have proper attic ventilation which plays a critical role for reducing temps and allowing the attic to breath. Code is 1 to 150. Meaning for every 150' of attic floor space, you must have 1' of ventilation. You can not over ventilate an attic in the South.

One last thing before I go, don't waste your money on powered attic fans. They are expensive, cost $ to operate, they don't last, some installations are a fire hazard, plus they can creat a negative pressure in the home and as a result, will draw in dust in to the home.

Good Luck!

I researched this issue 2 years ago as an owner builder, and now I've forgotten what I learned. Seems to me there's something you need to know about a minimum 1-inch gap between the foil and.....now what was it? It's very important, and I hope someone remembers what it is.

I installed radiant barrier in my home when it was constructed over 16 years ago. The attic space was considerably cooler than homes without the barrier and we had no problems with our roof. Our energy consumption on over 4000 sq ft is less than homes half that size.

I was not familiar with this technique before reading this series of messages. We live in Indiana - not Texas - 90's are common and this radiant barrier would provide some energy savings and improve the comfort level in the house. My question is: Where do I find these products? Would a home center carry them or do I need to find a specialty supplier? Thanks!

A good quality full service lumber yard for the foil faced plywood and a professional insulation company for the installed rolls of foil. These should be able to take care of your needs.

I have a large old fixer-upper in Baltimore, MD. Is it acceptable to install a rediant barrier and then apply closed cell foam insulation to the underside of the roof? I want to create a totally unvented attic space. This is being done in many South Western States.

I'm a construction professional with 22 years experience and i have never seen an unvented attic space and believe it would be a mistake. It may cause framing and decking to dry rot from the inside out. Foil faced materials are a good idea but the heating and cooling cycles may cause the foil to eventually degrade so ensure that the product you purchase is of high quality. The 1 to 150 ratio is correct but increasing this to 1.5 to 150 will also help significantly. This can be accomplished with gable and eave vents as well as roof vents. Venting is the key to a cooler attic and longevity of the roofing materials

Jerry O in Baltimore may be interested in some homes being built in New Hampshire where the insulation is applied on top of the sheathing boards and then a finished roof on top creating a vent free attic space. Saw it on HGTV.

Would adding a radiant barrier to a house with a steel roof provide any additional benefit?

We've monitored the attic temp in our central Texas home and never seen it go above 125 F, so I'm guessing that a steel roof sort of acts as its own radiant barrier to some extent.

Jerry O, skip the radiant barrier, and go with the closed cell on the unvented roof. The closed cell foam will keep the heat out, just as the radiant barrier will, and will seal all the air leaks in the attic area too. Code does allow unvented attics even in new construction, as long as foam insulation is used.
Jeff, a spray foam insulation contractor

When I did a 2-room addition, I used OSB sheathing with radiant-barrier applied to the underside (the barrier needs to be OPEN TO AIR on one side or the heat will just conduct through it to adjacent material). But not satisfied with an efficient addition, I also ripped the roofing and roof sheathing off from the tie-in all the way up to the ridge, replacing half of the old 1x12 sheathing with the same radiant barrier OSB. I will get to the other half of the existing roof next year, but after 6 uncomfortable Arizona summers in the house, I can say that this past summer was quite nice. The radiant barrier definitely works, as I have before/after experience. With a cost of about $.32/sq. ft. plus roofing paper (I used peel & stick membrane instead), it was 100% worth it to strip it down to the rafters (plus it saved on subbed-out labor, since elec, gas, mech labor was accessible from above) I have an existing metal roof which I re-used, so I have metal over membrane over OSB over a radiant barrier. Whatever does radiate downward from the metal roof is stopped & reflected back up by the foil. The extra expense of the metal roof was also offset by labor savings and future maintenance savings - well worth it since I am the end-user.

Thanks for all of the comments. I think that this Saturday is Radiant Barrier day at my house.

In the same vein but a different product.
Are roof turbines any good? I live in the Arizona desert and many of my neighbors have them but long ago a fan dealer told me they are useless. Comments, please, but facts would be better.
Thanks in advance

Rafters Versus, Just Laying Radiant Barrier on Top of Existing Insulation?
Labor wise just laying the barrier on top of the insulation would be very easy for me to do by myself. i have a house built in the 1890's with a very steep roof and getting to the very top of the rafters would mean getting on a ladder to staple to underside of rafters...
so which would be the best way to install the barrier?

Thanks, Charles

Hi Charles,
From what I have read, the idea is to keep excess heat out of the attic. It would seem that laying the barrier on top of existing insulation would not be that effective. My house is about a year old, but also has a steep roof. I used a 4 x 8 sheet of plywood as a base for my ladder. After getting everything up to the attic, the actual installation wasn't that difficult.

http://www.ornl.gov/sci/roofs+walls/radiant/index.html

Check out the 'Important Non Energy Considerations' and 'Installation Procedures'. Installing the barrier on top of the existing insulation can lead to moisture condensation and dusk accumulation.

Hope this helps.

We believe radiant barrier works but what kind should we get? We live in an old home in Euless Texas with a low roof. We are looking into having it sprayed. We would like to know if it is better to have it sprayed between the rafters or stapled to the rafters or the kind that lays on top of the insulation? Which works better? Are any of them scams?