Metal Roofing INSTALLATION question
#1
Senior Member

Thread Starter

modest apartment buildings that need shingles. A roofer said that metal is almost the same price as 3-tabs, so I'm leaning that way. He also said that I can save money by not having him install 1x4 nailers; he will leave existing shingles in place, and screw the metal to the decking on 16" centers; eliminating any wind lift.
Please, nothing needs to be said about code or what's in the book about it; just does it make as much sense to you as it does to me? Save on tear-off, save on nailers and labor, get a 50-year roof that I'll not have to worry about again...
Please, nothing needs to be said about code or what's in the book about it; just does it make as much sense to you as it does to me? Save on tear-off, save on nailers and labor, get a 50-year roof that I'll not have to worry about again...
#5
Admirals Club 


Not the way mine was done and not the way I would ever have one done.
#6
Admirals Club 


“Modest apartment building”. I just did gutter work on one last week. The roofs all had a nice wavy motion to them. Chances are you only have 1/2” ply under it. No way I would trust the holding power of the new roof to the guys luck in hitting hidden rafters.
I use a lot of standing seam metal on the vertical sides of places I build. I pay way more than three tab asphalt shingles would cost. what gauge metal is he using?
If you are spending the money I would want it ripped off, replace any plywood and run the 1x’s so you have nice flat surface.
#7
Senior Member



Put new metal roof on 3/2018 I had them put synthetic felt down over old (not leaking shingles) then metal right on that.
The roofer pre-drilled on the ground screwed it down in the ribs, NOT on the flat per the engineers.
My roof is permitted and inspected.
My roofer has his own Computer controlled Roll Former, he had a 5 week backlog and was cheaper than other quotes.
#8
Admirals Club 


Just finished my daughter’s house. Had a metal roof put on by a guy that has been doing them for 25 years and we are very pleased. He removed the shingles but did tell us that they could stay, then he put down 30# felt tar paper, then used 2x4 across the roof for the pearlings. He told us we could use 1x stripping lath. But he prefers 2xs he says the air gap under them helps with the insulation factor and the 2xs create a straiter roof. If there was a low spot they would put shims under it to make it straight. We didn’t need any shims. He also put the ice dams above all of the doors or anywhere someone could get hurt. All the 2xs we’re screwed to the rafters not the plywood they even used exterior deck screws, lastly the screws for the roof all had rubber washers and any screw that had the paint rubbed off by the screw gun, he had a laborer go around with a q-tip and apply paint on screw heads $12,500 not sure how many sq it was but roof estimates for 30 yr architectural dimensional shingles were approximately $10,000. We opted to remove the shingles so we felt comfortable about not having any bad plywood. If a peice was bad he charged $50.00 per sheet to install. Hope this helps.
#9

I had this done similar to what's in the photos but on a hip roof and it looks great, saved a lot of money like you're saying. Haven't had any issues and no more shingles coming off or letters from the insurance company. I think they used nailers of some sort to make it even but it turned out nice. I'll try to post some photos.
Last edited by scflats; 09-24-2020 at 07:35 PM.
#10

If it had OSB sheeting the screws will come lose over time. If it has1buys for roof decking the screws may be in a crack between boards. Not going to tighten. Use the strips. I use 1x6 the metal doesn’t bend or crease when you walk on it.
#12
Senior Member

Thread Starter
#15
Senior Member

Thread Starter
#16
Senior Member


i had a house done this way and had no issues.
#17
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Join Date: Aug 2003
Location: Sailfish Capital & Black Hills SD
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I'm no engineer, and have only the experience of living in a home that this exact process was done to in SE Florida for three years. It seems to have worked out fine. What I do know, is when it rains on a steel roof it makes more noise than a asphalt/shingled roof. My place out here in SD now has three unattached steel roofs (two porches and a carport), when it hails, need to turn up the volume on the TV!
So I would do it.
This from the installation instructions for the roof I just installed on my carport, Premium Pro-Rib by Midwest Mfg.. On the pergolas, I did on the flats, on the carport just the rib except I did both on the ends of the sheets. So far the pergolas don't leak (2 years), not rained on the carport yet. All are only 1/4-12 pitch!
So I would do it.

#18
Senior Member

I made that mistake! Don’t do it. Screws that missed the rafters and were just in the old shingles and decking started backing out due to metal expanding and contracting with temp changes. Lasted about 5 years before we ripped it all off and properly reshingled.
#19
Senior Member

decking is usually not very thick and is old.
shingles just take up some room and will not hold anything
new 1 X 4 or 6s (3/4") boards nailed to the rafters so you can screw into them will hold a lot better
#20
Admirals Club 


The boards seve several purposes. !st strength. They are screwd to the Rafters not the weak roof shingles. Second they provide air space so when roof sweats it drys underneath -metal can sweat.3rd tney provide a sound barrier for rain and other noise.
SDure you for go this and save as in any construction you can save by not doing it right.The best way is strip the old roof put down a sound insulation barrier and use the 1x4 and do it right. But since its an apartment building for rental money we know it will not get done right.
SDure you for go this and save as in any construction you can save by not doing it right.The best way is strip the old roof put down a sound insulation barrier and use the 1x4 and do it right. But since its an apartment building for rental money we know it will not get done right.