# metal roof coating



## lidco (Jan 6, 2007)

I,ve got a 15 year old metal roof on a barn. I know there are coatings to apply over top to fill any gaps and small holes I just can't think of the product name. It's an elastomeric. It also needs to rolled on. 

If any one has any tips:notworthy


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## AaronB. (Oct 6, 2004)

Its called polyurea, and its cheaper if its heated, mixed, proportioned, and sprayed on, rather than rolled on.


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## RooferJim (Mar 6, 2006)

We have had real good luck with GAF Topcoat. there patina green color is the closest match to real weatherd copper I have ever seen. 

RooferJim
www.jbennetteroofing.com


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## AaronB. (Oct 6, 2004)

Topcoat failed us three times. Applied to spec. That is why I do not use it. I am not telling anyone not to explore all the options.


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## RooferJim (Mar 6, 2006)

We have used topcoat quite a bit , mostley restoration of old copper roofs and gutters. had nothing but great results.

RooferJim
www.jbennetteroofing.com


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## Joasis (Mar 28, 2006)

I have never used it, but I have heard polyurea is a permanent system, that can be color tinted as well....it is just like the bed liner material without the non skid aggregate added....probably would go for $1.25 a sq/ft installed based on material cost.


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## AaronB. (Oct 6, 2004)

MOst truck bedliners are done with a spatter coat instead of an aggregate...

Material for a 48 mil membrane is running about a $1.25 a foot. Add prep, primer, etc, usually about 3 bucks a foot for a silver membrane. The color stable aliphatic will about double the material price if you go full color, but we have other solutions for the color requests whereas the material doesnt cost quite do much. Email me if you like.


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## Grumpy (Oct 8, 2003)

www.Adurel.com

Start with a thick urethane mastic over any fastener heads and panel seams, then apply at least one, preferrably two, coats of seamless monolithic urethane elastomeric. This is standard white and can be tinted to any color you desire. 

This is very similiar to GAF top coat but top coat is acrylic and we know acrylic is water based so I stray away from water based coatings. Adurel does make an acrylic but I seldom use it.

Aarons Ployurea is probably better but requires much more investment of equipment and basically is apples-oranges.


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## lucas (Feb 22, 2007)

Polyurea is expensive and not worth the investment. Better to get new metal for that cost.

Acrylic coatings are highly permeable. ASTM D 6083 allows up to 50 perms. Even if the coating meets this standard the manufacturer will have to incorporate a corrosion inhibiting primer. Most are water based and have the same issue with permeability. Permeable coatings allow oxygen and moisture to reach any rust which will eventually grow no matter how much RI pigment they include. An Alkyd primer is a better bet for acrylic based metal roof coatings. Acrylic on metal is best left for moderate climates and perhaps metal roofs previously coated with asphalt-based coatings.

Solvent based SEBS thermoplastic rubber based coatings are your best bet. They are highly impermeable averageing less than .2 perms. They level out better than acrylics and have less weather restrictions. Like all products there are some that are poorly formulated or over-economised.

Adurel has a good one MS2200


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## AaronB. (Oct 6, 2004)

So what makes polyurea not worth the investment? I dont think you have researched it thoroughly if that's your stance.

It cannot be beat in terms of:

Permeability
Shore A and D hardness
Tensile strength
Set time
Longevity
NO VOC's

And exactly what is the cost of polyurea, compared to the others mentioned? New metal is going for 5-7 a foot to swap out around these parts. I am not even close to that number.


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## tookalook (Feb 14, 2007)

*Metal roof coating*

all depends on where you have this roof dose it see temp changes like Canada or is it always above freezing dose it sit water and is there a coating already applied galv copper tin ??? lots of coatings will stick including new ceramic that wont allow any heat to transfer.


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## tookalook (Feb 14, 2007)

one thing i can tell you is to talk to a industrial painter not a roofer. do you want it to last or fail


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## AaronB. (Oct 6, 2004)

So youre saying to have the painter waterproof the barn? LMAO Some people will say anything for a laugh. LOL

The acrylics with ceramic really do not stop heat transfer. They do reflect up to 80% of UV initially (which turns to heat energy when absorbed), but are definitely NOT a thermal barrier.


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## Grumpy (Oct 8, 2003)

tookalook said:


> one thing i can tell you is to talk to a industrial painter not a roofer. do you want it to last or fail


Are we talking abotu roofing or painting? Call a roofer with experience in metal roof restoration. Do not call a painter to work on your roof. First off it's not likley a painter will have the proper ROOFING insurance which carries a higher rate than painting. Why is this important? If yoru PAINTER falls off the roof he will not be covered thus it's the building owner's insurance that pays.

Calling a painter is the worst roofing advice I have ever heard.


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## roofwiz74 (Oct 27, 2006)

a painter?good god where do these people come from?
The most important thing is to prep it right.and get a roofer to do it.


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## lucas (Feb 22, 2007)

AaronB. said:


> So what makes polyurea not worth the investment? I dont think you have researched it thoroughly if that's your stance.
> 
> It cannot be beat in terms of:
> 
> ...


Aaron

Perms: important - SEBS less than .2 - it's not water sensative.
Hardness: really not that important unless you expect a lot of traffic - it's a barn not a parking garage.
Tensile: important - SEBS 1200 psi vs acrylic @ approx 200 psi. It's 1/2 polyurea but more than enough considering it has 3 x the elongation.
Set time: a couple hours but skins over fast and won't wash off.
Longevity: 15 - 20 years to recoat. 
No VOC - - that's not a performance characteristic - make of it what you will.

Anyway, the fact is that it doesn't take steel plate to patch a wood boat. Polyurea can be a great product but it's blended on site and more subject to applicator error. It also requires expensive equipment and more training to apply. Generally its aluminum in color and therfore has much lower emissivity. The barn will be hotter in the summer. Polyurea is not for every contractor and it's not right for every roof. I've seen a lot of technologies fail. You only need it to fail big once to turn a believer into a critic.


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## AaronB. (Oct 6, 2004)

so you can't offer polyurea? Too bad. once again, you do need technical and productive expertise. It is hard to apply it incorrectly, given you have done the proper research and study to alearn the chemistry and application techniques, limitations, attributes,etc. Like any system, you do have to do it right, and not just any "roofer" (and I use that term lightly) can do it. That's where we shine. We have accomplished all of the aforementioned requirements in order to provide a superior prodct to our customers at a fair price. 

Yes, rooftops have foot traffic that will damage sebs, as well as tree limbs, hail, etc.

Still, what is your assumption on my installed price, say over metal?


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## AaronB. (Oct 6, 2004)

By the way, EVERY technology has had failures, why would you conveniently omit that factoid?


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## Grumpy (Oct 8, 2003)

I do SEBS, not polyurea and while I agree no VOC isn't a performance characteristic, I know from doing SEBS that VOC will sometimes shut down an office building fast.


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## Labour of Love (Mar 12, 2006)

*roofing paint for the North Country*

So, what would be your advice to the same question for those of us living in the far North? We hit 40 below from time to time - last night was a freakish 25 below at my place.

My roofing issues include not enough pitch on an addition to shed snow/ice properly AND the problem of acid rain destroying the finish on new steel (tin)roofing (interfering with the roofs ability to shed snow).

I'm interested in knowing whether I'd be better off with one of these new coatings or do I need a whole new roof?? And, if a new roof is my best option, what finish or product will hold up the best in terms of staying (over years) slick enough to shed the snow?

I'm in the landscape design/build business and this issue is wa-aaaay out of my areas of expertise. Thanks.


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## Grumpy (Oct 8, 2003)

Labour most of the methods above would waterproof your roof system. In addition many of the methods listed above are also sueful for very low slope roofs so you wouldn't need to worry much. I can't speak for SPF or Polyurea, but I know most of the urethanes and SEBS not only have rust inhibitors and are very chemical resistant. 

BUT if your roof has holes you need to at least repalce those panels with holes.

In regards to temprature, you are not going to want to apply any liquids, Urethane, Acrylic or SEBS in the cold, below 40. Sure the buckets can be kept in warming boxes and even admixtures can be added to the liquid to make them easier to work with and cure properly... but I still try not to do it when possible.


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## AaronB. (Oct 6, 2004)

FYI, our roofing grade polyurea passed 40 F below and bent 180 degrees without fracture. It is a heated product that can be applied in side freezers while in operation, and I have successfully instgalled it at 12 F.


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## Labour of Love (Mar 12, 2006)

*The only holes in the roof*



Grumpy said:


> Labour most of the methods above would waterproof your roof system. In addition many of the methods listed above are also sueful for very low slope roofs so you wouldn't need to worry much. I can't speak for SPF or Polyurea, but I know most of the urethanes and SEBS not only have rust inhibitors and are very chemical resistant.
> 
> BUT if your roof has holes you need to at least repalce those panels with holes.
> 
> In regards to temprature, you are not going to want to apply any liquids, Urethane, Acrylic or SEBS in the cold, below 40. Sure the buckets can be kept in warming boxes and even admixtures can be added to the liquid to make them easier to work with and cure properly... but I still try not to do it when possible.


are where the roofing nails were improperly seated and the gaskets aren't evenly depressed.

Would it be against the rules here to mention specific products?? I live in a VERY rural area and am likely to need help locating the right products.


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## AaronB. (Oct 6, 2004)

Definitelky not the waterbased products below 40, but I like to see 50 F and rising.


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## Labour of Love (Mar 12, 2006)

*I've confused us*

I didn't mean to make my inquiry sound like I needed a product that could be APPLIED cold. I meant to ask about a product whose surface would last under very cold conditions after proper application and curing.

I'm also sort of curious to know if the original threadmaker her had his/her question answered. I didn't mean to hijack - if just seemed fortuitous that our questions were similar.


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## erniesgutter (May 26, 2011)

AaronB. said:


> Its called polyurea, and its cheaper if its heated, mixed, proportioned, and sprayed on, rather than rolled on.


Yes sprayed on, rather than rolled on...


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