Opinion on this method

Guest User
2/9/2014
I am having a metal roof installed over architectural shingles that are about 20 years old (and leaking bady) on a hipped roof with a 3:12 slope. THey are about 3 days into the installation and have coverage on 80% of the roof. I am getting a galvalum, ribbed panel that is kynar 500 coated. My location is coastal, in hurricane alley. The company doing this install is known in my area for being the best, so I trust what they are doing, but I wanted to get some opinions on what they are doing. What he is doing is standard procedure for him and his installs performed well during hurricane Katrina. Here is what they are doing: 1.) They took the shingles in the places where I had leaks and replaced the 3/4" deck where it was rotten. In those places they put down ice and water shield. This was in valleys and near skylights 2.) Then over the whole roof they put down a synthetic underlayment, it is grip-rite shinglelayment (polypropelene). I am told this has radiant barrier properties, but without an air gap it doesnt do much for you. 3.) It is required to do 75 screws per square here, but they are using 100 per square because that is their standard. They are going straight into the decking/existing shingles. They say this will get a higher wind rating than using fewer screws on 1x6" strips. The metal has dimples that are visible if you face the roof parallel with the rib patern. My deck roof was straight and the deck was solid, but I guess this is normal to expect some dimples because of the fact the shingles are architectural and the plane isn't completely flat? The washers dont look panned out, so I dont think they torqed them down too much, but there are some dimples. The picture I attached shows this, although it may be hard to see because the roof is shiny right now and has alot of reflection on it. Is it reasonable to expect some dimples? I looked at other roofs in my neighborhood and it's harder to see dimples because they are steeper slopes and they are faded somewhat. 4) They put a drip edge trim on the fascia boards that goes up the deck far enough to cover several inches of the underlayment. The deck edge of the trim is flat the fascia board edge has a bend. 5.) I have soffit vents and and a ridge vent which they are leaving. 6.) they are not putting closure strips at the ridge and the eaves. (this was one of my concerns). The panels hang over the drip edge several inches and have a course of screws that goes through the panel and the drip edge. The panels are sealed down pretty tight on the flat parts, but the ribs of course are not. Seems like it would take a pretty significant wind driven rain to get water in there. He says if any gets in there it will run back out over the underlayment and drip edge. (is this legit or should I push for closure strips?). Seems like you'd want any condensation to have a way out also. THanks for your opinion
Eric Novotny
An informed customer is the Best Customer!
2/9/2014
Sounds pretty comprehensive in approach. I would prefer to have seen the underlayment over the drip edge so that any moisture that gets behind the panels sheds over top the metal but we also seal our drip edge to the deck with peel and stick flashing tape. Some dimples are probably going to be unavoidable but everything else sounds pretty good. I would respectfully disagree with them in that you can get as secure an attachment over purlins/battens if done right.
Guest User
2/9/2014
Eric, thanks for the comments. He said going over battens decreases the wind rating because of the separation it creates. I'm impressed so far, other than the dimples it looks great. you can only see them during certain times of the day. In full sun you don't notice them because the roof is shiny. It was overcast yesterday and they were easy for me to see. But i'm a bit of a nitpicker. Today it is sunny and that roof surface is not hot at all. My house has stayed cool all day without running the AC. It got down to 59 as an overnight low and right now the house is 70 and the AC hasn't run at all. And, they haven't even cut the barrier back to put the ridge vents in yet, so im' sure once they have the attic will be even cooler.
Eric Novotny
An informed customer is the Best Customer!
2/10/2014
Awesome feedback. Post up some pictures.

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