BUR And Acrylic Coating

coolflatroof

Hi all,

I have a roof in question. It is BUR with loose gravel, over a metal deck. a little ponding, but nothing major.
Owner is money-conscious, and is looking for the cheapest way to to make it waterproof for 3-5 years.

I was thinking IB, but it is a little too much money for him. So I'm thinking Acrylic coating with aluminum base coat. All from the same manufacturer.

Here is a technical question. How do i prep the
existing roof for the coating?
I plan to power-broom the gravel as thoroughly as possible, but there will be some stones stuck in the asphalt. Also the roof surface will not be smooth.

Here is what Mfg's spec says:
1. All existing surface contaminates such as asphaltic mastics, peel and stick membranes or other roofing materials shall be removed to expose the underlying surface to which new materials are to be applied. Loose aggregate is to be removed by mechanical means such as a “wet-vac” process.

I suppose "asphaltic mastics" is that black crap sold in 5-gallon pales at Home Depot used to repair these roofs. But the roof is 230 sq. and all black. How do I know what is asphaltic mastics and what is not?...

Any way, have you guys been involved in something like this? What is your experience? Please give any advise you can. What should I do about roof imperfections?

PS, I've worked with this stuff before, but that was a metal with a fairly smooth surface, and no bitumen products.

Thanks

ProSpec

Unless you're able to get ALL the gravel embeded in the asphalt off you're asking for trouble. You need a smooth surface for the coating to adhere properly. And the embedded sotnes will prevent a uniform coating - picture trying to cover every surface of every embedded stone unformly. Yoiu might be able to do it if you slop it n real thinck - but then the coating cant's cure properly - it will skin over and stay like bubble gum under the skin. And never use an aluminum coating under an acrylic - the acrylic will not stick to that and you'll have coating peeling up before you walk off the roof.

Good luck

rc-construction

Thats not correct. I have coated thousands of square feet of BUR with gravel and it adheres just fine. It depends on the manufacturer. Find a good one that has an asphalt prep coating. The easiest way to clean it is to power wash it. You might spring a few leaks but they will just drip momentarily. Use the thickest napped roller pad you can get to roll it on and it will adhere just fine. I have coated entire walmarts that were old and got 7 yrs out of it. If it is that small just swrew down some plywood and conklin will give a factory warranty on it.

tiny

Why dont you try kold king or a ram material and flood coat .

Grumpy

What every liquid you use you are going to need to do a flood coat for sure. I install Audrel elastomerics from time to time. I bid one job that was a gravel roof and we were going to sweep it, but not spud it, then apply a base coat of black urethane and a top coat of white acrylic. The cost ended up being more than if we were to tear it off and go back with a modified, due to the incredibly high price for material and the incredibe ammount of material necessary to flood the imbedded rock.

You can find cheaper products and accomplish the same "roof coating" to lower the cost somewhat but you will still need roughly 10 gallon per square, at a cost of about $45 per gallon. That's $450 a square JUST for material. Add labor and the number of repeat visits required and you will easily be at $600 a square (your cost) IMO.

You have reputable roofing companies in my area that would do the same roof with a tear off, 1/2 fiberboard and modified for $550. The improperly insured and unlicensed handy men would be doing it for about $300.

Slyfox

I did a grocery store last summer under the same situation as you,
"Owner wanting a cheap repair until he has the money to replace"
and you end up walking a fine line between reputable and scabbish work so remember if it comes between losing the job because you couldn't meet his price or doing work that won't last, lose the job.
In my case he settled on the fact that he had to spend more or find some one else and he got a good job but as grumpy stated he could have done a complete re roof at only about 35% more than what he paid for the repair.

In my case we:
Swept the entire roof.
Spudded 100% around all penetrations including walls.
Partial spudded the field, making sure no bulky spots gravel.
Roof cement and cotton meshed all penetrations, blisters, bad laps etc.
Coated all repaired areas and penetrations including along walls first, "heavier".
Coated field normally.

Edited to correct 35% more could have layed over, not re roofed.

__________________

theroofinggod

or sweep it secure 1 1/2" iso with screws and plates ,and then install a new single ply system on that

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