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jjrbus 10-21-2012 03:35 PM

Energy saving roofing materials
I have been wading through tons of info on asphalt roofing shingles for SW Florida. Lots of tech terms and info. Then I came across a site that indicates very small actual savings on so called energy efficient shingles. So now I am totally confused? Any input? JIm

joecaption 10-21-2012 03:47 PM

Good luck with that idea.
Ligher colored shingles, SIP panel installed before the shingles, properly air sealed attic and plenty of insulation in the attic, proper venting will 100% sure save energy.

burnt03 10-21-2012 05:19 PM

Any more info on the SIP panels? How thick are they, vapor barrier built in, R-value, rough price per sq ft, etc?

joecaption 10-21-2012 05:28 PM

Not cheap, just Google it.
All depends on what type roof you have.

Windows on Wash 10-21-2012 05:50 PM

Energy savings all depends on what type of roof system you have and what the attic is like.

Is there HVAC equipment in that attic as well?

jjrbus 10-21-2012 08:15 PM

Really appreciate all the imput but at the moment I just need to figure out the best bang for the buck for a simple tearoff and shingle replacement job. Will not be doing anything exotic. Will post picture and ask about venting later. I think I see an issue there.

I guess the best question would be are the Energy Star/cool roof rated shingles worth the xtra cost?

Windows on Wash 10-22-2012 04:55 AM

Yes and no. If you have proper insulation and no duct work in the attic, they are not. If you have duct work in the attic, in FL they would be of benefit.

You need to supply more information.

jjrbus 10-22-2012 07:23 AM

Thanks for the response!

Years on the internet and I never supply enough info

Cape Coral area FL. Roof is oriented in a northern direction with a 7/12 pitch, may be wrong on pitch? Cathedral ceilings in house with AC and duct work in attic space, using scissor truss's. Duct work looks good was probably replace with AC 7 years ago.

I have not closed on this house yet so am missing some info, but need to put on roof immediately upon closing or will lose insurance.

I do not have pic yet so will add link, showing picture of house. For the ridge vent should it be full length on the roof and should it be added to the garage? Soffit are perforated aluminum. I suspect that Lani (screened porch up north) in rear was added after construction and venting was blocked to attic, assuming they moved the aluminum soffit from house to lani.

If there will removing blocking to venting be adequate from lani to house?

I also suspect some damage to truss ends due to inadequate guttering on front of house, there is no code requiring gutters so will remove them when roofing.

Am I asking the right question? JIm

Windows on Wash 10-22-2012 10:01 AM

The more reflective shingles are usually a good investment in Florida and especially if you have duct work in the attic.

The duct work is usually insulated poorly and the reduction in attic temps will help all the systems work a bit easier.

jjrbus 10-22-2012 10:25 AM

One article/study I read claimed very little difference in savings for energy efficient roof shingles but made no mention of AC in attic.

Their claim was the savings could be as low as $42 a year on average house.


AGWhitehouse 10-22-2012 11:06 AM

There's no way to put a true $$ to a roof shingle without knowing the specific house they are installed on. The lighter the color, the less UV will be absorbed, the less heat will be gained. This will result in slighty (and I mean slightly) lower temperatures within your attic that will result in slightly (again, slightly) lower heat gain within your ductwork. As hinted to above, proper venting of the attic space is more effective at latent heat control than the color of the shingle.

Grumpy 10-22-2012 01:44 PM

Reflective shingles won't be much savings at all, because if the attic space is a properly ventilated space the actual difference of thermal transfer from a black roof to a white roof is only 2 degree attic temperature. Key on the properly ventilated.

Read the following articles I wrote about this topic,

SIP panels may void or limit your shingle warranty. Read the warranty document before choosing this option.

AGWhitehouse 10-22-2012 01:54 PM


Originally Posted by Grumpy (Post 1035798)
SIP panels may void or limit your shingle warranty. Read the warranty document before choosing this option.

Look for "Ventilated nail-base panels" for roofing applications. "SIPs" as you'll find in a google search are predominately used for wall applications.

Grumpy 10-22-2012 02:11 PM

Yeah I like those vented nail base panels, I hit on that in link to the article I posted above. HOWEVER what we don't know is if this roof structure is a warm deck or cold deck design. If it is a cold deck design I can install R 30 blown ni fiberglass for the price of R 9 poly iso rigid insulation board. So converting it from cold deck to warm deck isn't really advised. In my opinion if the roof is currently a cold deck design it is much better to honor the original design, insulate the ceiling and insure proper attic ventilation.

If it is a warm deck design, then my opinion changes. I would opt for the vented nail base and opt for a reflective roofing shingle, and still proper ventilation. Though proper ventilation is harder to achieve with vented nail base in many cases.

AGWhitehouse 10-23-2012 02:41 PM


Originally Posted by Grumpy (Post 1035814)
Though proper ventilation is harder to achieve with vented nail base in many cases.

How so?

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