Metal Roof Installed Over Shingles? | West Michigan | 2024  

I just installed a standing seam over shingles. I inspected the osb sheathing from the attic with a flashlight and it looked good. We used 1-1/2" pan screws and they were grabbing strong. I think it will be a good roof. I'll give an update in 30 years.

We have big overhangs and high winds, so I’m kinda glad we got our metal roof installed on top of our existing asphalt shingles. Extra sound deadening and extra weight are kinda nice. The roofing company did install purlings first then metal.

Some years ago, I did exactly what you're saying not to do. However, I did not put the metal directly on the shingles. First, I installed horizontal 2X4 purlins attached down to the decking through the shingles, then spaced four feet apart, i inserted a 1" piece of foil faced styrofoam sheeting between each of the purlins. then attached the metal with 2 3/8" inch zinc SDST screws with rubber washers. Due to the steep pitch of the roof, no water penetration has ever been noticed. I was using 24g galvalume R-panels. It appears as if this roof was installed directly on the shingles, which, I agree, doesn't sound like a good idea. Oh, and the roof I covered was in good shape, no leaks known anyplace on the entire roof. Thanks. New Sub. :)

I had a contractor tell me that samething. Wanted to leave my shingles on and then charger 14k to install. I told that man to get out my yard. 😂

Great insight!

Good advice my guy! I hate seeing metal over shingles just lazy business practices.

Thank you. I almost made this mistake having a guy install metal over my old roof. When I brought up the facts you presented in this video you’d think I was insulting him. I have leaks currently from hail damage and think it’s highly probable that we have deck boards that are rotten….. the roofer said that makes no difference when putting metal over the top of it. I asked about securing new material and screwing into rotten wood…..he danced around that question. I’m opting for a new shingle roof so that I know the deck is properly inspected….. and I went with a different reputable company.

Roofing company did this to me. We had to get a new roof per our home insurance because of age in Florida. The metal option was cheaper. I asked if they were gonna rip all the shingles off for that price and he said yeah. The day they showed up i gave them about an hour and they had half the metal already on over the shingles. 🤦🏻‍♂️ i made the call to their boss and it was a $3,000 upcharge to remove the shingles. I wish they were more clear upfront, because im getting drywall cracks in my ceiling all around the house. Thats alot of freaking weight up there being an 1800 sqft house

Did they install purlins first or right on top of the old shingles?

It’s because the metal was installed directly on top of the shingles and it needs to have a 2 x 4 or a one by four installed on top of the shingles for the metal to be screwed onto if you do not the shingles will work like a sandpaper on metal and it will wear through and you do not put the screws into plywood or OSB. They will work loose.

The mistake was going directly on shingles. You must first frame-in horizontal furring that structural attaches to the rafters, then the decking issue becomes obsolete, because your metal is fastened to the purlins, not the decking. This also creates a breathable air gap, behind the Metal panel, which helps reduce condensation and keep your roof deck/attic cooler, because the reflectivity of Metal is greatly reduced when fastened directly to the deck, without an air gap. Certainly a poor excuse of an install here.

Sounds like it wasn't even half installed right so not all the metal over shingle fault. You don't just buy panels together then caulk between them. There is massive installer error here.

Of course it’s going to go wrong screwing onto shingles. Install purlins first and it will be fine.

Really looks like the roof was in bad shape from the start and not installed properly as you pointed out along the side wall. I wouldnt put all blame on the steel or shingles. I feel both ppl were crappy installers. Ive installed steel over shingles and have had no issues but the roof was also in good shape if the roof is crap i always tell owner we have to rip off shingles and start fron scratch.

do you think that it may have leaked due to the fact that the fasteners were installed in the low spots? That's the big mistake. Guaranteed leakage. You have to put the screws in the high spots.

Lol this guy would have a hard time selling in my area. He's literally replacing a premium roof product with asphalt shingles. He's replacing an ok.roof with one that will need to be replaced after the first 1.5" hail. Yeah a poor insatll a poor install.but an asphalt shingles is literally the most fragile.roofing product yiu could put on a roof. 😅 he probably doesn't even know this.

Metal roofing is designed to be fixed through the ridges not in the valleys .

No. Just don’t do it. Tear-off, Do it right the 1st. time or don’t do it at all. Why isn’t the previous roofer being held negligent & therefore paying for the replacement?, is that at all a possibility?