TOPIC: I Have An Existing Metal Roof and Have A Question
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So, 1 year old galvalume plus roof, oak trees over it made a mess of pollen and sap and dirt. I (homeowner) brooms the loose stuff off and hoses it down. But it is still filthy. Proceed to hose roof down again and clean it with strong mix 1/3 Krudd cutter / water, brush it down with a deck brush and then hose it off really well. It looks great- when on the roof. But on the ground, there are now dull, low sheen areas, kind of a haze mixed in with gloss areas, all glossy is how the entire roof looked when installed. I know I messed up with the cleaner being too strong (should pay more attention). I am thinking I stripped off the acrylic coat in some areas. Or at least made it soften and haze. Is the aged look of a bare galvalume, a “flat” sheen or glossy. Like I said, it looks great when looking perpendicular to the roof, when I am up on it, but spotty sheen changes when looking from the ground. Could I have messed up the substrate or is it most likely the acrylic and it will wear away and blend as a lower gloss sheen bare galvalume. If so, how long should it take for the remaining acrylic wear away and start to blend in. Thank you for your help
My guess is that you did strip away some of the acrylic and started some oxidation of the bare metal. Normally the acrylic takes 5 - 7 years to wear away.
So this should slowly even out? Is the final aged product of bare galvalume glossy or matte looking, is it darker or lighter than when first installed?
Because the now-exposed areas will always be accelerated in their weathring, I doubt this ever "evens out" but, yes, things do dull down after the acrylic is gone so the visual difference will likely lessen over a period of many years.
Thanks for the information,
Follow up question(s), so what “color” and sheen does the Galvalume (plus) age to over time? From what I have read, the galvalume will become darker and more of a matte or flat finish VS the light gray/silver and gloss that it has when new. The reason I ask is because, the section where I “over cleaned” is almost white in color when the sun is coming from over my shoulder, but when the sun is overhead, there is NO visible difference, and when I am on the roof (looking down at it) there is NO visible difference, only when at a shallow viewing angle and the sun is behind me is the discoloration visible. So, I am thinking I softened and scuffed or put a chemical haze on the acrylic in some places, which should even out over time. OR if I removed the acrylic and “shined up” the galvalume, I am thinking it is going to dull out over time, and darken, assuming that it does normally “darken” some with age vs getting lighter in color with age. I just cannot find any examples of truly “aged” galvalume.
Also, I have read where the acrylic layer is super thin, like less than 0.001”, and more like 0.0001”, which is basically not measurable, does that sound right?
I believe it will dull down to more of a matte and gray look rather than silver. There are folks out there more familiar with this than I am though. Let's see if anyone else answers. As far as the film thickness of the clear coat, I'd expect it to be in the .0001" - .0002" range.
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