I Just Painted My Asphalt Shingle Roof in 109 Degrees

[SDREMNGR]

I've read good and bad things about using elastomeric roof coatings for asphalt shingle roofs.  I'm in San Diego where the moisture and rain is minimal so I took a chance and painted the roof today in this 109 degrees heat.  It was hot as balls.

After 1 coating so far, here is what the temperature difference is at 3:30 pm.  Outside is 108, inside is 88 and it feels pretty cool.  I can totally deal with this weather without running AC.

I'm hoping that with the 2nd coat, it'll improve slightly more but I'm very happy with the result so far. The cost was $105 per 5 gal bucket and each covered about 150 s.f. on one coat.  It's thinner than what they recommend but I'm happy with heat reduction and less concerned with water proofing.

[Milspecstache]

Nice job!  You will have to report on the results.  The second coat will spread much further in my experience.  I'm guessing you are putting white paint on black shingles?  If so I bet you will see immediate results in your inside temperatures...

[AMustachianMurse]

It's so hot here...make it stop....lol.  My Mustachian apartment is mustachian in price because no A/C.  I'm dying.  Luckily there aren't too many days like this during the year, but I am reserving the right to be a complainypants about it.  Though at least neither of us are in fire danger.  Hope every one you know is safe and not evacuated. 

[Another Reader]

The old folks do this on the old asphalt shingle roofs in Sun City in Arizona.  The coating devalues the houses there considerably.  Everyone assumes the roof needs to be replaced.  This stuff is great for flat tarpaper roofs and metal mobile home type roofs, but causes the shingle underlayment to rot, even in dry climates.  The roof can't breathe.  Many of these products state they are not designed for asphalt shingle roofs. 

My guess is your neighbors will not be pleased by the appearance.  At $105 per bucket, that stuff gets expensive.  What will it cost to put two coats on your roof?

Next time you reroof, look at radiant barriers.  The builders are using them in Phoenix now.  Same benefit, normal looking roof.

[SDREMNGR]

The product I used was a specialized "roof paint."  Not just any generic exterior white paint.  It's an elastomeric compound that is much thicker and has tiny ceramic grains to help reflect light.  It reflects 96% of light.  I did read about some of the asphalt shingle roofs having issues and the asphalt shingle roof industry associations warn you against using it.  I did my research and I felt that it was worth the gamble.  I have 3 solar attic fans that I installed that I had bought at a local auction that sells Costco return items.  I got them for only $27 / fan.  It retails for $369+tax.  Here in sunny San Diego, they run pretty much from 10 am to 5 pm all year round.  So I'm not too worried about moisture being trapped in my attic.

(http://www.costco.com/Professional-Series-Solar-Powered-Attic-Fan-with-Solar-Controller-by-U.S.-Sunlight.product.100104427.html?catalogId=10701&keyword=solar+attic+fan&langId=-1&storeId=10301)

For the days that are cloudier or if it's really hot after sun down and I want to have it run into the night, I bought this.

http://www.costco.com/.product.11619363.html?cm_sp=RichRelevance-_-itempageVerticalRight-_-CategorySiloedViewCP&cm_vc=itempageVerticalRight|CategorySiloedViewCP

When there is no sunlight, it automatically monitors temperature and humidity and stays on when above 80 degrees or 75% humidity.

The roof was probably about 10 years old already but it looked pretty solid and I haven't had any problems before the coating.  The coating, when applied to flat roofs that it is marketed to be coated over, is supposed to extend the life by 15 years.  I am hoping that my current roof will last another 15-20 years.  We will see.  Perhaps it will be less, but I think I will more than make up for the cost of the coating and the cost of the new roof by eliminating the A/C bills over the summer. 

I have a 1350 s.f. house and I think it will take me about 10 - 5 gal buckets to paint it all thoroughly with 2 thick coats.  So it'll be about $1000 with my 5% off Lowe's card.  I'm pretty happy with it so far already with just 1 coat.  The temperature differential was really nice today.  Outside was 90 degrees but inside was 73 degrees.  That's very doable for me without A/C running.

 

[Milspecstache]

What color is your siding?  That also makes a difference...  at least on the South side

[Another Reader]

The elastomeric coatings are sold to senior citizens by slick door to door salesmen.  They sell it using the same points, extending roof life and reducing cooling costs.  It works to some extent, but it looks pretty sad after a few years.  A roof is comprised of some pretty shingles and the underlayment, the part that actually keeps you dry.  The shingles protect the underlayment from the sun and allow air to circulate.  The coating does not allow the underlayment to breathe.  The underlayment deteriorates and the shingles start to curl.  These houses are more difficult to resell, because the assumption for a coated roof is the roof is at the end of its life.  The agents I know in the Sun City area warn their clients to avoid coated roofs.  You don't see many new applications.

If anyone has had a good experience with coating an asphalt shingle roof in a hot dry climate, please chime in.

[SDREMNGR]

What color is your siding?  That also makes a difference...  at least on the South side

Probably a beigey off white.

[SDREMNGR]

The elastomeric coatings are sold to senior citizens by slick door to door salesmen.  They sell it using the same points, extending roof life and reducing cooling costs.  It works to some extent, but it looks pretty sad after a few years.  A roof is comprised of some pretty shingles and the underlayment, the part that actually keeps you dry.  The shingles protect the underlayment from the sun and allow air to circulate.  The coating does not allow the underlayment to breathe.  The underlayment deteriorates and the shingles start to curl.  These houses are more difficult to resell, because the assumption for a coated roof is the roof is at the end of its life.  The agents I know in the Sun City area warn their clients to avoid coated roofs.  You don't see many new applications.

If anyone has had a good experience with coating an asphalt shingle roof in a hot dry climate, please chime in.

I personally think it's a matter of taste, but boy do people hate white roofs.  The only place on Earth where being white gets you hated.  Maybe, 2, roofs and Compton.  The shingles curl because after 3-5 years of super hot sunny weather, the paint dries and cracks and curls.  Part of this can be remedied by proper application of 2-3 coats that is thick enough to keep it's inner moisture so that it does not dry and curl.

As for marketability, I do agree with you there.  I did this for my sanity and reprieve from the heat.  It is working out great so far and the heat differential is amazing.  If time came to sell the home, I would probably reroof with lighter colored shingles.  It would be about time to reroof at that point anyways.

[Another Reader]

Wonder how it would look on my orange S-tile roof......

[SDREMNGR]

Wonder how it would look on my orange S-tile roof......

Awesome!

https://www.youtube.com/watch?v=_EPu1ZhzDOM#t=88

I found support for the cause!  It's also very Mustacian.

[Flaneur]

The elastomeric coatings are sold to senior citizens by slick door to door salesmen.  They sell it using the same points, extending roof life and reducing cooling costs.  It works to some extent, but it looks pretty sad after a few years.  A roof is comprised of some pretty shingles and the underlayment, the part that actually keeps you dry.  The shingles protect the underlayment from the sun and allow air to circulate.  The coating does not allow the underlayment to breathe.  The underlayment deteriorates and the shingles start to curl.  These houses are more difficult to resell, because the assumption for a coated roof is the roof is at the end of its life.  The agents I know in the Sun City area warn their clients to avoid coated roofs.  You don't see many new applications.

If anyone has had a good experience with coating an asphalt shingle roof in a hot dry climate, please chime in.

I'm an east valley roofer who does a lot of repairing/replacing of coated shingle roofs in the retirement communities and almost every coated roof tear-off we perform will reveal rusted nails/staples, moisture around skylights/pipes/vents, and watered-down underlayment & sheathing. On flat roofs the coatings work great and even in Arizona we can expect nearly a decade out of them but on shingles not so much. Shingles aren't designed to be covered with anything -- the system is designed using gravity to pull water down the slope of the roof on the shingle and sometimes through it via capillary action. Shingles ventilate themselves by design, with vapor escaping between the shingles. Coating the roof prevents water from running down the shingle when it inevitably gets under the surface and doesn't allow the shingle to vent itself.  If the roof is not properly cleaned and prepared the coating won't last long (it may not last regardless, depending on the brand) as well. Check your shingle manufacturer warranty as manufacturers generally don't cover shingles which have been molested.