Roof re-coating - possibly DIY project?

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Old 06-16-09, 06:10 PM
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Exclamation Roof re-coating - possibly DIY project?

Dear all, how are you doing?

We are in the process to replace our low-slope roof with mod. bit. (dibiten) with coating. Our roofer quoted us $4300 for the roof with "aluminum roof coatings", and said that if we want to have "cool roofs" (see APOC 252 Sun-White Premium Elastomeric Roof Coating @ APOC - Roof Restoration, Waterproofing, Pavement Maintenance Systems), then we will have to add US$1000. Some questions here:

1. Is it true that the Elastomeric roof coating would last longer (more durable) than the "aluminum" roof coating? According to henry.com, they seem to last about the same, which is about 7 years).

2. So I guess after 5- 7 years later, we will have to re-coat the roof again. Is there any differences about how to re-apply the coat with "Aluminum" vs. "Elastomeric coating"? Could this be a DIY type of project? It seems that for elastomeric coating, you basically apply it with roller, that's it. As we have a relatively small roof, that's why I was thinking maybe we could do the re-coating ourself?

3. Any thoughts or comments on this product "APOC 252 Sun-White Premium Elastomeric Roof Coating"? How does this product compare to other manufacturer's similar products, such as henry.com or firestone products? Thanks!
 
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Old 06-17-09, 05:50 AM
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Welcome to the forums!

Is this a metal roof? or plywood?

On metal, the aluminum fibered coating will stop/hide rust and seal minor leaks. It also reflects the sun. The elastromeric coating does a better job of sealing leaks but will not hold back rust. All rusty or suspect metal must have a good coat of a solvent based primer applied first.

I've use an elastromeric roof system on new flat [or near flat] roofs. it consists of applying the coating, laying down a membrane and then another coat or two of the elastromeric. It holds up well! I've never recoated any but assume it would be as simple as cleaning and rolling on another coat of elastomeric roof coating. If there were any cracks or the membrane lifting - they would need to be addressed frst.
 
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Old 06-17-09, 11:45 AM
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Hi marksr, it's a plywood roof.

For more photos about this roof, please see PictureTrail - Gallery

Based on my research, it seems that even if we go with the aluminum coatings right now, if after 5 years later we need to recoat it, we could still choose white elastomeric coating later. Can anyone confirm this? Also for a area of around 600 sq ft, does adding material/labor cost of US$1,000 to switch to elastomeric cool roof reasonable? Many thanks!
 
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Old 06-17-09, 02:08 PM
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I'm not familiar with the aluminum coating system for plywood roofs

I'm a painter not a roofer and am only familiar with the elastromeric system because 20-30 yrs ago I worked for a company that did painting and water proofing - they used that system, in fact we used it on our shop addition, 5-6 yrs before I quit and it held up well.

Hopefully someone knowledgeable in these systems will respond.
 
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Old 06-17-09, 02:16 PM
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Theres a few roofing guys around..just give them a couple of days..most are busy now.

That really looks like regular roll roofing (kinda like shingles on rolls) to me. Not like the stuff they use out here where its heated with a torch and then coated. There may be layers we can't see of course.

As I said..wait for a roofer to weigh in..unless there is a time crunch.
 
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Old 06-20-09, 08:30 AM
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Elastomeric is more "elastic" therefore will weather better especially in freeze thaw. I'm not sure of your climate, but here in Chicago, silver coat will flake after a few years and needs to be re-applied every few years just like paint. I've never got 7 years out of silver coat.

In regards to the elastomeric it depends on the quantity and number of coats. You can get 15 years and actually a warrantable build up liquid roof system. The longevity of the elastomeric will vary based on a few factors being the slope of the roof, any ponding water, and the type of coating. We install a few manufacturers elastomeric but although I have heard of APOC I am unfamiliar with their product. Urethane based is a much better product with bettr adhesion and better water resistance and an acrylic based elastomeric.


That's a decent looking roof and dibiten is a good manufacturer. That is a torch applid from what I can tell, not a 90 lb miner roll. You have a granulated white surface which is more reflective than a smooth black but not nearly as reflective as an elastomer coated roof. However it will also require more product to cover the granulated surface.

My concern is that lower pan area where no doubt the water is intended to collect and drain. If an acrylic elastomeric is installed in that section, I would fear it won't last long at all. The water will simply break apart an acrylic based elastomer and therefore a urethane based elastomer is preferred for those ponding areas.

Another thing to keep in mind that if the modified bitumen is smooth (for anyone reading this) it needs to weather for a few months to allow for the sanded surface to wash away as well as the surface to develope minor surface cracks for better adhesion. Painting it on day one will most definetly reduce the longevity of the first application.


My only one concern is the application of roof cement to adhere the radius and the complete lack of a mechanical fastening. Eventually, maybe 5 years, maybe 10, the roof will become unadhered from the edge of the building at the entire perimiter and will become an entry point for water infiltration. This has nothign to do with your question but is a concern of mine for the overall longevity of your roof. I wish you had more pics.
 
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Old 06-20-09, 08:44 AM
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Ok sorry to spam post. I just realized two things. 1) you are in california and I heard rumor that torch applied roofing was banned years ago. I could be wrong so do not quote me on that. It's also possible they didn't torch applied and used cold process instead. I don't know why I assumed it was torch applied, but after looking at other photos I think it's not torch applied at all.

What is that tar spot on the roof?! If my guys left something like that on the roof they will be fired. Elastomeric nor silver coat will adhere to that mess, it needs to be cleaned up as best as possible. That "chocolate" is the problem since it liquifies in the heat and the excess needs to be removed. Why did they do that?!


Those asphalt patches won't last long term, they do not look reinforced. In addition they are totally exposed to the UV which will break down the asphalt in less than 10 years. Finally I just can't image why they did that. Plus when it cracks you'll get leaks around those pipes.

I do not see a "cant" strip at the base of the chimney. Modified bitumen is not meant to be a 90 degree angle and needs a cant strip to break that 90 degree into a 45 degree. A can't strip is nothing more than a 45 degree wedge placed where the roof meets a wall.

As far as the satellite dish goes, two comments. 1) the instalers get paid peanuts so you get monkey workmanship. It's understandable why they don't care, I wouldn't if I got paid slightly above minimum wage and was working 80 hour weeks. Also with it installed on the chimney that's better than on the roof. Although preferrably they'd never have punctured the membrane at all and would have set it on a ballasted plank set on pads. I'll see if I can find a pic.

The roofers really should have removed those old rusty mounting brackets before installing the new modified bitumen.
 
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