There isn't a whole bunch of options there.

You sure a removal and re-roof isn't the right path.

You will burn through a ton of material on that filling all the cracks with coating and if there is any water in the substrate, it will fail the coating.

 

You can use quite a few different coatings on a built up asphalt / bitumen surface like this. Its going to depend on your budget and what you are looking to get out of the effort you put into it. It will also matter if its leaking in spots or not. The picture looks like a roof that has been weathered pretty well but those are just as you stated surface cracks and may not be leaking yet, its also a small section of a larger area.
I would address any spots that are leaking first with a heavier fibered petroleum based roof coating/ which is a filler and refresher for built up/ bitumen/asphalt roofs. Its heavy enough to fill in some of those larger cracks but will spread well enough to get good coverage of larger areas. If some of the cracks are close to the width of the pen in the picture then an asphalt or modified roof cement would be better for just the cracks, and then coating over the top. Think of it like treating an asphalt driveway every couple of years. There are fibered Aluminum roof coatings that can be used which add reflectivity and longevity but also are more expensive and there are also white/colored polymer coatings that you could use to almost get a "new roof" thickness(40 mills) out of but those are considerably more money. A 5 gal pail of Fib Roof coating may go for around $25-$30( I have not checked current pricing) where as the Aluminum coating may go for $65-$70 both coverage rates are about 1-1.5 gals per 100 sqft. So you can figure out your area and what your going to spend from there. A covering with out the Aluminum may last you 2-4 years depending on the weather, and the Alum may add another 3-5 years depending. I hope some of this makes sense and helps. I am a newbie to this webpage and I have 18 years experience in the roofing industry on the distribution side and some installation and some in between. There may be some better suggestions out there also but this is a good place to start.

 

Thank you somuch oldtimer.
That's very helpful.
When I apply the coating, is the final effect really sensitive to the surface cleaness and moisture? If so, I have to wait until next summer or spring.
It doesn't leak rightnow, except a little bit drip on one of the draining point with water accumulated on the roof.

I found this on homedepot website, homedepot is only one block away.
http://www.homedepot.com/p/Henry-4-75-Gal-555-Premium-Aluminum-Roof-Coating-HE555019/100094951
Is it work? What does the 'aluminum' mean?

 

Hello,

We bought a property last year, with the garage and storage room has flat roof. No need to say it's a 100% stupid design in this North West Pacific Region.

I really hate when people say things like this. What do you do for a living? Let me go a head and say how dumb of an idea that is. Moving on, a properly designed and installed low slope roof will out last 90% of any sloped roofing. The issue is it's expensive, and people are cheap. So to blankly blame the roof is incorrect.

The roof is coated by bitumen material.

The question is coming:
Its surface cracks, or 'alligatoring' in more spesfic terms, due to its age. (I am not sure how long since last installation)
The current condition of some bad part is pretty similar like this picture I found on internet (i have attached).

What you have is a top mopped/flood coated roof, once the roof layers are (felts/Cap sheet) are installed a coating of asphalt is mopped or poured to the top of the surface. Once that is aged a short while it is then alumacoated. These are the protective layer of the roof system. So times and IMO a better way is to added pea gravel in to the flood coat. Either way something has to cover/coat the poured asphalt otherwise it cracks like you see there.

How can I treat it by myself, to extend its life at lower cost? And what product is more proper to apply? Any idea?

Thanks guys

Does the roof currently leak? If the roof does not have any leaks then all you need to do is clean the roof very good. Broom brush and wash. Let it dry for at least 24 hours and coat it with aluma coating. You can get fibered and non fibered aluma coating. Various manufactures have different rates of Aluminum in the coated that effects reflectivity. We rarely use fibered Aluma coating, and to be honest the last time we used some it was Henrys, like was stated before plan to coat ever 3-5 years. 3-5 years is what should be expected, and this is generally what happens, people do not keep up with the coatings. It is a maintenance item. I wouldn't fool around with mastic in the cracks as it is not needed. Any repairs you do with mastic the mastic will need to cure for 30 days before coating.

When I apply the coating, is the final effect really sensitive to the surface cleaness and moisture? If so, I have to wait until next summer or spring.
It doesn't leak rightnow, except a little bit drip on one of the draining point with water accumulated on the roof.

I found this on homedepot website, homedepot is only one block away.
http://www.homedepot.com/p/Henry-4-7...5019/100094951
Is it work? What does the 'aluminum' mean?

Yes the roof must be very clean and free of debris. Clean it well and wait at least 24 hours if in a good sunny area before coating. Fix the leak first, there shouldn't be any leaks even with standing water. A low slope roof should be water proof, they should be able to hold water. Unlike a sloped roof that is water repellent/shedding.


The Henry coating is fine, like I said the fibered is not needed but if that's what they have that's what they have. The non fibered will be a little less expensive.

Post some actual pictures of your roof. Specifically the leaking area.

 

Does the roof currently leak? If the roof does not have any leaks then all you need to do is clean the roof very good. Broom brush and wash. Let it dry for at least 24 hours and coat it with aluma coating. You can get fibered and non fibered aluma coating. Various manufactures have different rates of Aluminum in the coated that effects reflectivity. We rarely use fibered Aluma coating, and to be honest the last time we used some it was Henrys, like was stated before plan to coat ever 3-5 years. 3-5 years is what should be expected, and this is generally what happens, people do not keep up with the coatings. It is a maintenance item. I wouldn't fool around with mastic in the cracks as it is not needed. Any repairs you do with mastic the mastic will need to cure for 30 days before coating.




Yes the roof must be very clean and free of debris. Clean it well and wait at least 24 hours if in a good sunny area before coating. Fix the leak first, there shouldn't be any leaks even with standing water. A low slope roof should be water proof, they should be able to hold water. Unlike a sloped roof that is water repellent/shedding.


The Henry coating is fine, like I said the fibered is not needed but if that's what they have that's what they have. The non fibered will be a little less expensive.

Post some actual pictures of your roof. Specifically the leaking area.

Thanks mate.
It doesn't really leak currently, except a little bit drip at the connection betwwen the roof surface and a draining point on the center, if water ponded arround.

Recently it rains alot, and leaves fell on the roof. A line of tall poplar trees beside the building. So there is alot of debrits, especially in the fall, and the debrits clog the draining points sometime, I have to clear it manually.

I will post some actual pictures later. The picture from internet that I posted looks pretty similar with some parts of my roof.
Should I wait until rain season over to do it?
What't the best way to clean the surface throughtly?

Here is a link to homedepot roof coating catalog, which one work for me?
http://www.homedepot.com/s/roof%20coating?NCNI-5

 

Here is a picture I just took. It shows some cracks on the surface.

 

if iit were mine id use elastomeric with the matting. wouldnt have to worry about it for many many years. if your going cheap, well cant help you there, i dont do cheap, but then i have to guarantee my work.

 

What's the difference between Elastomeric and Fibred Aluminum coatings? Which one will works better for me? Thanks

 

Most elastomeric coatings will not hold up to ponding water. Alumi coating sort of will. You will triple the cost doing elastomerica and poly matting. Another down fall of elastomeric coatings is that the asphalt will bleed through the coating so it will not be as white. They do of course make some that do not allow the asphalt to bleed through but it adds more to the cost.

Again I say fix the leak,

Coat the roof in alumicoating.