DIY Attic Radiant Barrier

How-to for a cheap homemade radiant barrier for your attic. Radiant barriers battle the problem of emissivity in attics. When the sun beats down on the roof the shingles store energy then slowly gives that energy out in the form of radiant energy. So if you had a widget that could reflect that radiant energy away from the ceiling and back into the roof you could essentially reduce attic temperatures, therefore reducing your air conditioning load and save MONEY.

Step 1 Items and Tools

To make the radiant barrier you will need a small list of easy to find items. This list started me out and I made 240 square feet of radiant barrier. The limiting factor is the spray adhesive. The can says that it coveres 220sq.ft. but I was using double that rate. This made approximately ten 12'X2' (24sq.ft.) lengths.
Parts:
1 Roll 36" X 33.3 yards painters Masking Paper (hardware store)
2 rolls of 12" X 75' generic aluminum foil (grocery store)
2 cans of 3M Super 77 spray adhesive (hardware store)
Tools:
Tape Measure
Broom
Razor Blade
Staple gun w/staples

Comments

[geosuz]

Thx for your article - but I was wondering has anyone thought to connect the vent the cool house crawlspace to the attic?

[rcg40]

While hemming and hawing I decided to buy a remote thermometer (10 bucks Walmart) and put the remote in the attic and the reader in the hall. Hohum, hohum, the temp in the attic is higher.
So I put some money in the mix. I started logging the following:
time, inside-temp, outside,temp, attic-temp, KWHRS from meter.

For me to stay 77 inside, while it is 98 outside, and 121 in the attic, the KWH reading is higher.

Tomorrow I install radiant barrier. Next week, I will have some numbers

[charlieb000]

one limit to this is it reflects outsude heat out, but in winter you want inside heat reflected back in. and you need shiny on inside too. so double the foil.

[jimknight]

The radiant barriers shown on the picture are good.it clear the idea how it would be useful to install and comfort with installing radiant barriers.

http://www.kleenairservices.com/

[jimknight]

Nice, you got it less than $250. Can you give me a link or more any informatiom regarding from where u got it?.
Thanks to share this with us. T
hat is the nice idea to know the process and install it with ourself and savings.

[adambeazley]

When i was first researching radiant barriers, I was going to use the store bought aluminum foil, but found that its just easier, cheaper and better to just buy a heavy duty double sided radiant barrier from a good company.

I got 2,000 sq ft for less than $250 and did the installation myself. I definitely notice the savings and the attic is much cooler in the hot summers down here (Louisiana). Here is the stuff I used: Raflect Radiant Barrier

[mathieulj]

Cheaper? take a peak @ BlaineC's post higher up. Apparently he covered the same ground with less than 1/5th the cost. Although it is true that he might not get as good of insulation as the commercial product but you cant say he paid more to get the job done.

[LVGene]

..sigh..

Well if you were going to use Foil..  Might I suggest you go to a commercial / (Near Commercial) food store.  The kind of store that sells to Restaurants. 

Special Costco's, Smart & Final, are the stores I'd use here in Las Vegas.

They sell heavy duty and very WIDE foil.  I wouldn't even attempt this kind of DIY without heavy duty foil.

Hope this helps.

GENE

[RadiantFoil]

Radiant barrier works well in both warm and cold climates.

During cold winter months, up to 75% of your home or building's heat can be lost through your attic area.  You may already have fiberglass or cellulose insulation in your attic but these types of insulation only RESIST heat transfer.  Radiant barrier REFLECTS up to 97% of radiant heat back toward the living space, keeping your home warmer and saving you on energy costs

Radiant barrier installed under the roof rafters in your attic can reflect up to 97% of the sun's radiant heat waves away from your attic keeping your home cool in the warm summer months.

More information: EcoFoil Radiant Barrier 

[SpudMaker]

FYI, here is a good video of installing radiant barrier attic foil.

[Energyefficient]

Why make radiant barrier when you can purchase a much better product for the same cost of these items. Not to mention that kitchen foil isn't nearly as effective as the real thing. It is not pure aluminum. Just buy a roll of ARMA FOIL or some other brand. It will be much stronger and will perform much better.

[Energyefficient]

http://www.energyefficientsolutions.comHere is another good radiant barrier site showing several different locations and methods of installation.

[lego411]

oh, and you could get a two-for-one if you use this in conjunction with tesla's radiant energy collection thingy. ... and hey, if you coat your entire attic, you have yourself a faraday cage too! three birds with one tin foil... er.. multiple tin foil... aluminum actually...

[HapiBnBusiMom]

This site has a lot of good radiant barrier information and you can buy online too:

http://www.radiantguard.com

[tacamaral]

I believe you could also paint the roof white - that would reflect a lot of heat, as well. I might be wrong on this one, but would painting the underside of the roof black help in any way?

[SpudMaker]

I needed 4000 ft for my home. I purchased heavyweight double sided Radiant Barrier Attic Foil from AtticFoil.com Check out their install method for high pitched roofs.

[knexfan9182]

ouch you have space to move around in lol

[BlaineC]

Living in south Louisiana, we have very very hot and humid summers. But I am cheap. So I inquired with the Dept. of Energy web site about the wisdom or foolishness of using store-bought Reynolds Wrap foil instead of the Home Depot style radiant barrier roll. The only difference is in how easy or difficult it is to handle the foil. The paper backing and fiber reinforcement gives the Home Depot product more strength so it doesn't tear as easily, but this does not have to be air-tight. So I went to Sam's Club and bought three 500 ft. rolls of the restaurant-grade heavy duty foil. Turns out my 2300 sq. ft. house only needed about 2 rolls at $20 a roll - $40 - not bad. It did tear occasionally but it was manageable. I suspended the roll using a short piece of pipe hung with two pieces of rope nailed to the rafters on one end of the attic and just walked it across the whole length of the attic to the other end, then stapled it up, then did the next row. I had a wide open simple square attic so this was much easier than if there were lots of intricate spaces, but I don't think the paper-backed product would have been significantly easier. I left about a foot from the eaves and the roof ridge so air could enter and leave. Unfortunately, my a/c unit died a few months later and I replaced it with a much more efficient unit so I have no before-and-after measurements to know how well it worked. I eventually installed a powered attic ventilator fan which was the strong recommendation of my A/c man - about $100. This makes a big difference as well, although it consumes electricity (unless you buy the solar-powered version for more money).

[tradergordo]

I'm very interested. But would have liked to have seen some good controlled before/after testing. I'd also like to know why you leave the gap at the top? For example it looks to me like the heat would just reflect back to the roof underlayment, generating a lot of heat in the air space between the barrier and the roof which would then just rise to the completely open top and fill your attic with hot air. I guess this would not heat the attic floor as much though? I don't know, my attic floor is completely covered with insulation - the attic can get extremely hot but the room ceilings below my attic don't get that hot - I'm kind of wondering if I would get any benefit from this or not? And how about another idea - couldn't you GREATLY simplify the whole thing but just stapling aluminum foil directly to the roof supports horizontally across the entire attic? You wouldn't need to do anything with paper, cutting, gluing, etc. You might need some special heavy duty foil though, not sure - but you'd definitely want to be very careful when doing the stapling. Perhaps it would be better to use silicone sealant beads instead of stapling? Come to think of it, that might be a really good idea. Silicone sealant is very cheap ($2-3 a tube) and can withstand temps up to 500 degrees F. It bonds to most surfaces and then you wouldn't have to staple anything. Just some thoughts...

[crowdjs]

foil by itself would be great but foil at the store does not have good tensile strength and thick foil with good tensile strength would be very expensive. The paper gives the right amount of tensile strength needed.

[tradergordo]

My guess is that most people don't need the extra tensile strength unless the attic is being used as a living space or something - there isn't anything to tear it. But if you wanted to, you could get a roll of saran wrap of the same width, and put the two together so they unroll together, that would give you enough extra strength, but still low cost and ease of installing.

But after reading the site that was linked here (http://www.ornl.gov/sci/roofs+walls/radiant/index.html) it seems I will probably not get any savings from this, and most people would probably be better off just putting in more insulation. I'd measure your actual ceiling temperatures before going though all the work.

[jeff-o]

This is a great idea. I did a bit more research, and found this site:

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

It provides some great background information on how the radiant barrier works, where it can be installed, and some extra info on using it in really cold climates. I'm planning to renovate my attic in the next year or two, and will definitely consider adding a radiant barrier in addition to traditional insulation.