Metal Roof Coating?

[Boomyal]

I own a small commercial/industrial building, about 3000 sq ft. I has a low pitch corrugated metal roof that is covered with surface rust. Otherwise if appears to be in good shape but eventually the rust would take it's toll.

I've made several inquiries, including the building contractor, for a sevice that would coat the roof, thereby extending it's life. All to no avail. Seems like the builder, once they are done, don't want to know anything about maintainance of their buildings.

It would be impractical to clean the rust off the roof before coating so it would seem that there should be something that would tie up the rust before any coating was applied.

So if anyone has any experience, I would appreciate any input on rust treatment as well as suitable roof coating.

 

[Bob_VT]

Re: Metal Roof Coating?

Is it a decent pitch? How visable is it? I would say rustoleum (POR 15 would cost too much) and maybe paint a rubberized coating on it similar to a tar.

I would clean it off a bit before I did anything. My neighbors barn which is huge has a metal roof and he has it painted every 5 years. They do scrape the rust before they paint.

 

[Boomyal]

Re: Metal Roof Coating?

It's a 2 or 3 to 1 pitch Bob. You can walk on it. It could be easily pressure washed but the overall light rust coating would be too much to try to clean off. It needs something to render it inactive, like Rust Doctor or possibly POR15 solutions. However, as you surmized, either of those would bankrupt you.

There has to be some commercial 'stuff' to do it. Then it would not keep growing and lift the top coat off.

 

[Kenneth Brown]

Re: Metal Roof Coating?

I don't know how to kill the rust without killing your pocket book too but I do know what you want afterwards. Its called Elastomeric coating. One of the brand names is SnoWhite. I worked with a painter freind for side money a few years back. We sprayed the stuff on a metal office building. It sealed all the little leaks, made it pretty again, and drasticly reduced the load on the guys AC system.

 

[Boomyal]

Re: Metal Roof Coating?

I don't know how to kill the rust without killing your pocket book too but I do know what you want afterwards. Its called Elastomeric coating. One of the brand names is SnoWhite. I worked with a painter freind for side money a few years back. We sprayed the stuff on a metal office building. It sealed all the little leaks, made it pretty again, and drasticly reduced the load on the guys AC system.

Yeah, KB, your solution, Pt B, is exactly what I had in mind. Protect the metal and be more reflective. I'll keep hoping for a solution to Pt A. I'm sure that surface rust would like to be tied up before any topcoating.

 

[bjcsc]

Re: Metal Roof Coating?

Find out who sells blasting abrasives around you. Around here, you can rent the whole rig (compressor, blaster) for ~$250 a weekend. Even comes with the abrasive of your choice. You could use a medium cut and just dust it and you'd get exactly what you're after. Then you could use their compressor and a texture gun to spray the elastomeric coating on. You'd be finished in one day...

 

[JRJ]

Re: Metal Roof Coating?

If it isn't leaking, you're ahead of the game. My guess is the roof, rust and all, will last a long time. Good luckd

 

[dingbat]

Nothing special about “tin” roofs. Have been dealing with them forever.

How old is the roof?
Painted or galvanized?
How bad is the rust?

If the surface rust is just “streaks” you can paint right over it. If you have a bit more rust, you can use trisodium phosphate at a ratio of one cup trisodium phosphate to one gallon of water.

Apply to any rusty areas using a sprayer. Give it a good 15 minutes to penetrate the rust and start working. Then, using a hard-bristled scrub brush, scrub all of the rust and remove as much of the staining as possible.

If the rust is flaking, you’ll need to “repair” the damage. I use a wire cup (crimped) brush on a 7” grinder to remove the damage material then prime with Rust-oleum Stop Rust primer.

For paint, I’ve used 2 coats of Rust-oleum enamel in the past with good results. The barn roof is going on 25 years now. The roof on the house I grew up in is going on 35 years.

Lots of “roof” paints on the market as well.

 

[jbcurt00]

@dingbat try to avoid posting in old inactive topics, its been 13+yrs

I deleted a spam post & its poster that dragged this up