| we just finished lining the ceiling of our glassed-in porch and also underneath our overhanging eves with galvalume (galvanized corrugated aluminum). (it's not on top of the roof -- you look up at it). it's reminiscent of the old corrugated iron shed roofs, but really beautiful.
however, it has developed hundreds of whitish/gray spots, which look like a venting/condensation problem, although the spots do not rub off like dried cloudy condensation spots usually do. it's brand new, so i don't think it's corrosion, although who knows?
the spots run along near the wall of the house, about a foot wide, exactly where the old soffit was. this is occuring on the galvalume under the eves, but not the galvalume on the sunroom ceiling. (i think the sunroom ceiling, which is 10'x20', has more space above it and therefore the air moves around more, so there's no venting issue.)
i looked at the mfg. website (U. S. Steel), which says that "storage stain" can occur if the materials are stacked without ventilation, causing white or black spots. maybe it's related? (the mfgr. does not warranty the materials if the area is not vented properly and the GC and the architect are coming out to look at it next week.
when the galvalume went up, it was spotless and beautiful. does anyone have any experience with this? I would like to get some information before meeting with the builder. THANKS. |
