White Seal Roof Coating to Lower Attic Temperatures

Patrick · 09-04-10, 04:27 PM

I decided to try some white roof coating to lower my attic temps and therefore hopefully lower my AC power consumption. My shingles are a very dark (not black, but close) asphalt type. I bought White Seal from Home Depot as the coating material. It's Energy Star rated and warranteed for 10 years. I bought it in the 5-gallon containers @ $64 each as that was much cheaper than by the gallon.

I didn't take attic temps before I started, but later I found my infrared thermometer and took some temps on the roof and at the attic vent.

The temp on the roof itself at 12:00 with full sun yesterday was 104F on the coating and 155F on the bare shingles.

Ambient was 88F and the attic outlet temp was 90F. My latitude is 36 degrees N.

The air conditioner seems to run less than before. Next year I'll be able to report on the difference in kWh used.

Daox · 09-05-10, 08:34 AM

Wow, if the attic is only blowing out 90F air and the white shingles are only 104F that is AMAZING vs the 155F shingles.

How far does 5 gallons get you sq/ft wise?

Patrick · 09-05-10, 08:44 AM

Quote:

Originally Posted by Daox

Wow, if the attic is only blowing out 90F air and the white shingles are only 104F that is AMAZING vs the 155F shingles.

How far does 5 gallons get you sq/ft wise?

I would say about 30 sq ft/gallon, or 150 sq ft/5 gallon bucket. I might have put it on too thick, though. I hope the 2nd coat won't require as much material.

trikkonceptz · 09-06-10, 03:53 PM

Would you photograph the entire home with roof view once you are done? Here in S. Florida, we have to deal with alot of issues, county, HOA's and such and seeing photos of what a completed roof looks like it better than describing a "White Roof" on a house that normally has darker shingles..

Thanks ..

Patrick · 09-06-10, 06:09 PM

Quote:

Originally Posted by trikkonceptz

Would you photograph the entire home with roof view once you are done? Here in S. Florida, we have to deal with alot of issues, county, HOA's and such and seeing photos of what a completed roof looks like it better than describing a "White Roof" on a house that normally has darker shingles..

Thanks ..

OK, but I'll probably have to get on a ladder. You can't see the roof from the street. Only my neighbors with 2 or more story homes or decks can see it.

Daox · 09-07-10, 10:15 AM

BTW, I just remembered. I had found something similar to this a while back. The guy used hydrated lime which I'm not sure how environmentally friendly that is but... well thats what he used. His results were fairly impressive too.

Painted white roof drops house temps 8-10 degrees

benpope · 09-07-10, 12:52 PM

I am impressed with the results. I have a 1000 sq ft portion of my roof that is nearly flat and a good candidate for painting. However, for the visible parts, my wife won't go for a bright white roof. I realize that white reflects more visible light than any color, but are there any reflective roof paints that come in colors other than white? Discounting visible light, there is still plenty of energy to reflect in the UV and IR band, so there has to be something. File:Solar Spectrum.png - Wikipedia, the free encyclopedia

Patrick · 09-07-10, 10:55 PM

Quote:

Originally Posted by benpope

I am impressed with the results. I have a 1000 sq ft portion of my roof that is nearly flat and a good candidate for painting. However, for the visible parts, my wife won't go for a bright white roof. I realize that white reflects more visible light than any color, but are there any reflective roof paints that come in colors other than white? Discounting visible light, there is still plenty of energy to reflect in the UV and IR band, so there has to be something. File:Solar Spectrum.png - Wikipedia, the free encyclopedia

It's tough to get even close to white: http://www.azcoolroof.com/downloads/...g%20Materi.pdf

Patrick · 09-07-10, 11:23 PM

Wait, here's one: Planet Supra Thermal Barrier Paint

benpope · 09-08-10, 08:28 AM

Thanks- those look good. Now I just have to figure out how to pay for it. :-/

09-04-10, 04:27 PM	#1 (permalink)
Patrick Apprentice EcoRenovator Join Date: Jul 2010 Location: East Coast of Florida, USA Posts: 136 Thanks: 2 Thanked 3 Times in 3 Posts	White Seal Roof Coating to Lower Attic Temperatures I decided to try some white roof coating to lower my attic temps and therefore hopefully lower my AC power consumption. My shingles are a very dark (not black, but close) asphalt type. I bought White Seal from Home Depot as the coating material. It's Energy Star rated and warranteed for 10 years. I bought it in the 5-gallon containers @ $64 each as that was much cheaper than by the gallon. I didn't take attic temps before I started, but later I found my infrared thermometer and took some temps on the roof and at the attic vent. The temp on the roof itself at 12:00 with full sun yesterday was 104F on the coating and 155F on the bare shingles. Ambient was 88F and the attic outlet temp was 90F. My latitude is 36 degrees N. The air conditioner seems to run less than before. Next year I'll be able to report on the difference in kWh used. (Support EcoRenovator.org & get rid of these annoying ads!) Attached Thumbnails Last edited by Patrick; 09-04-10 at 04:31 PM.. Reason: add latitude.

09-05-10, 08:34 AM	#2 (permalink)
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 2,989 Thanks: 131 Thanked 89 Times in 73 Posts	Wow, if the attic is only blowing out 90F air and the white shingles are only 104F that is AMAZING vs the 155F shingles. How far does 5 gallons get you sq/ft wise? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-07-10, 10:15 AM	#6 (permalink)
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 2,989 Thanks: 131 Thanked 89 Times in 73 Posts	BTW, I just remembered. I had found something similar to this a while back. The guy used hydrated lime which I'm not sure how environmentally friendly that is but... well thats what he used. His results were fairly impressive too. Painted white roof drops house temps 8-10 degrees __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-08-10, 08:28 AM	#10 (permalink)
benpope Helper EcoRenovator Join Date: Jan 2010 Location: Memphis, TN Posts: 80 Thanks: 13 Thanked 8 Times in 7 Posts	Thanks- those look good. Now I just have to figure out how to pay for it. :-/ (Support EcoRenovator.org & get rid of these annoying ads!)

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09-06-10, 03:53 PM	#4 (permalink)
trikkonceptz Helper EcoRenovator Join Date: Jul 2010 Posts: 44 Thanks: 3 Thanked 0 Times in 0 Posts	Would you photograph the entire home with roof view once you are done? Here in S. Florida, we have to deal with alot of issues, county, HOA's and such and seeing photos of what a completed roof looks like it better than describing a "White Roof" on a house that normally has darker shingles.. Thanks ..

09-07-10, 12:52 PM	#7 (permalink)
benpope Helper EcoRenovator Join Date: Jan 2010 Location: Memphis, TN Posts: 80 Thanks: 13 Thanked 8 Times in 7 Posts	I am impressed with the results. I have a 1000 sq ft portion of my roof that is nearly flat and a good candidate for painting. However, for the visible parts, my wife won't go for a bright white roof. I realize that white reflects more visible light than any color, but are there any reflective roof paints that come in colors other than white? Discounting visible light, there is still plenty of energy to reflect in the UV and IR band, so there has to be something. File:Solar Spectrum.png - Wikipedia, the free encyclopedia

09-07-10, 11:23 PM	#9 (permalink)
Patrick Apprentice EcoRenovator Join Date: Jul 2010 Location: East Coast of Florida, USA Posts: 136 Thanks: 2 Thanked 3 Times in 3 Posts	Wait, here's one: Planet Supra Thermal Barrier Paint