Chalking Metal Roof

[GymRat]

I have a client that repainted his metal roof and the paint is chalking. This is on a 2 story house and is rather steep. He is planning on repainting the roof again, but needed me to prep it by removing the chalking. What would you recommend to downstream or xjet on the roof from a distance and then rinse off without having to get up close and personal.


Thanks, John

[814jeffw]

My first thought is peeling. The repainted metal roofs I see always seem to be peeling more than anything else. Unless it's the regular aluminum roof paint that has the consistency of tar. But anyhow, I would suggest a butyl based or hydroxide based or a concoction of the two, but not sure at what strength, because it sounds as though it could be touchy. Meaning if its not peeling now it may lift when you try something, and then that will be a bigger job than you probably counted on. That's just my first impression.

Jeff

[GymRat]

Originally Posted by 814jeffw

My first thought is peeling. The repainted metal roofs I see always seem to be peeling more than anything else. Unless it's the regular aluminum roof paint that has the consistency of tar. But anyhow, I would suggest a butyl based or hydroxide based or a concoction of the two, but not sure at what strength, because it sounds as though it could be touchy. Meaning if its not peeling now it may lift when you try something, and then that will be a bigger job than you probably counted on. That's just my first impression.

Jeff

I have not seen the roof, but the homeowner says it is not peeling, and it is paint that is designed for metal roofs, but is chalking after only a few years.
I hear you on it turning into a bigger job than I counted on with probably a few surprises. This is a big old farmhouse that the roof is high enough to scare Me.
Thanks Jeff for the quick comeback.

[814jeffw]

Maybe a test spot is in order here. Get up close and inspect it at least.

Jeff

[dnegri]

Getting chalk off a a metal roof is like getting chalk completly off concrete and stucco its just not going to completly come off . If its just chalking and not peeling just clean it like you would for prep for painting a house and let him know that he is going to have to seal the metal roof with an acrylic sealer before painting so that the new paint has something to adhear to, or if he wants ot be lazy he can buy a product called emulsa bond which he can get at his paint store or HD and follow the directions mix it with the 1st coat of paint and it will work just as well as the acrylic sealer he should get 5-10 years depending where you live before it chalks again you can use any tp of the line satin or semigloss finish.
I would use the emulsa bond my self ,smarter not harder

Dave Negri
Elite Home & Property Services

[GymRat]

So, are you saying, I can downstream my normal housewash formula, plus maybe a little TSP, and rinse real well would be an adequate prep?

[deach]

I can only tell you that when I prep for myself I still use some "pressure" to rinse off. I cover I've used emulasa bond but my sherwin williams rep told me it was a waste of money. The most important part of any paint job is the prep. You won't get "all" of the chaulky stuff off. as long as you hit the roof with some pressure after letting some S/C and TSP sit there a bit it will be ok for him to paint over it as long as he doesn't wait too long.

[dnegri]

I've used emulsa bond for the last 20 years in the in Florida the one of the worst states for chalking. After the prep is done the chalking paint is going to have to be sealed with a sealer of your choice if it is not sealed the chalk acts like cancer and eats hrough the new paint weather its the top of the line paint or the cheapest


Dave Negri
Elite Home & Property Services
334 East Lake Rd # 220
Palm Harbor Fl 34685
727-599-9252

[deach]

Right I agree. If not primed (I consider that part of the prep) with a good primer/sealer you're gonna have problems. I'm not saying emulsa bond doesn't work to some degree. I'm saying no matter what you add to a "finish coat" if the prep isn't right it's not gonna hold up.