Radiant Barrier Info/ Is it worth doing? (Austin, Roma: house, construction)

[twesley4521]

Hello All,

I did a search in this Austin forum for Radiant Barrier and was suprized to find little info. Has anyone done this in there Attic? Is it worth it? Any extra info would be great.

We are getting two quotes on Wednesday.

Thanks

T

[xsloane]

If you don't mind all the risks associated with aluminum usage then I suppose it can be ok.

[centralaustinite]

Do it!! It makes a big difference and keeps the attic space (and hence the heating ducts cool).
Mine was done as part of the original construction, it is part of what makes our house a three-star green built house (CoA). My current house is more than double the size of our old house (newer 3 star green built with radiant barrier and 6 inches of insulation in the walls, tight ducts, and properly sized A/C vs 1951 construction, no wall insulation, insulated attic, updated ac) but our electric bills stayed the same! So double the sq footage for the same amount of electric usage. Not all of that is due to the radiant barrier, Low-E windows help too. We are now looking for another house and will end up with older construction again, we will have a radiant barrier put in immediately!

s

[woodinvilleguy]

What is the issue with Aluminum?

Our house is going to have it with R-40 insulation and a 16 Seer AC so I'm interested in the issues.

[timfountain]

I looked into this a year or two ago, as our electricity bills are high ($500-$600 PM at this time of year). We were quoted $4500 to do the barrier, and we might save 10-15% on our electricity bills. The payback was 7-10 years if I recall, and it would need re-doing if we had to have a new roof (needed one after 5 years due to hail). It didn't seem like a good investment for us.

[FromCalitoSteinerRanch]

The way we approached the issue was to take the "up to 20%" claim and added all the remaining numbers, which are 0-19%. I did a spreadsheet and did a 5%, 10%, 15%, and 20% payback timeline, and decided against it. The builder would not budge on price, and they were making about 200% profit.

By the way, we have a two story, ~3650 sq. ft., and our average utility bill is $205 per month.


Oh, that is water, gas, and electric in that figure. It is based on the last 18 trailing months, ending in May. June and July this year with the record temps will affect the average if I redid it, but we are glad with our decision of NOT doing it. Now if the builder would throw it in for free, then that is a different payback timeframe altogether.

[twesley4521]

What I’ve ready on-line is that the spray-on version is not very good and the most expensive but the foil version in more effective/cheaper and if you install it yourself it might only run you about 400.00 for the materials depending on the size of your attic. It’s going to take some work installing it but I think my wife and I can put it up with out killing each other. But from what I read above the aluminum might kill us in the process. If you don’t see a post from me in a week call 911 and tell them were in the attic. Just kidding

Cheers from my Coors Light Aluminum Can


T

[texdav]

It is definelty worth it has you will also see your air conditioning unit not working so hard to keepup in the middle of teh day in the summer. Also nice of you have to go or store stuff in the attic. Keeps even the garage alot cooler it seems.Most energu star homes have it when built.

[Schwartz_Austin_09]

I would say that the radiant barrier might not be the best choice for energy bill reduction -- even though we did it. The guys that came over to our house and quoted it and installed it said that the best energy saving thing/cost effective thing we could do right off the bat was sealing the leaks in our ducts. The duct leakage was apparently well over 33%. The next best thing they mentioned was for us to have our entire house sealed up - plumbing holes under kitchen sink, caulking around the windows, door trims and other areas. Last and a very important measure is the attic insulation as the avg Austin home only has around 5-7 inches I believe.

Needless to say, we had them do all of this and the radiant barrier as well since the City of Austin and Austin energy gives a good rebate to help cover the bulk of the cost. Plus this company took care of all the paperwork.

[yam]

I'd like to get radiant barrier on my house but can't retrofit it due to cathedral ceilings in some rooms and lack of attic access in others. I had thought I might see if it could be installed from above whenever I have the roof replaced next time, but I don't know whether that would be practical. I imagine it would involve ripping off the roof sheathing so it might get expensive. Any comments?

Also wondered if a metal roof would create the same benefit as a radiant barrier. My understanding is that the radiant barrier benefit only requires a shiny surface with adjacent airspace above or below. Doesn't a metal roof do the same thing?