Home Forums Hunting & Shooting Hunter's Campfire Metal Roof OK Over Shingles?

And the bees love it too.

If you still want to go the halfass route, 1x4 over the shingles. Make sire those 1x4s are attaching into rafters. Preferrably wth a 8p ring shank.

The weight myth is a non issue.

Cap those 1x4 exposed edge off with 'mini corner'

Fugg the air gap

Cut 1-1/2" wide strip out of that old decking at the ridge cap. It'll vent with perforated vented ridge capping

Because it means warranting materials you did not install, and labor you did not provide. That previous roofing material is already compromised, or it wouldn't need repairs. It may sag, swell, shift, buckle, or separate, dragging the new material with it, causing issues that the roofer will have to fix. It's a simple case of avoiding a possible problem later.
As for the weight issue being a myth, that is not true. It varies from place to place, but either 3 or 4 levels of shingles is the max for a "nail over".
I grew up in the construction trade, worked as a roofer, carpenter, punchout man, drywall, masonry, I ran one of two crews for a general contractor.
Something not mentioned is the pitch of the roof. That has a great deal to due with the acceptable load on that roof. You will note that areas with high snow fall, also have sharply peaked roofs, so the snow load does not collapse the roof. (Helps to have an Engineer for a father)
I, personally, will not do a "nail over", even if they are legal for a couple of layers. It's half-assed, it does increase the roof load, and it does not expose problems with damaged or rotting roof members or sheathing. (You can't see it, so you just don't know. )
I would suggest doing the tear off, and examine the wood beneath, correct any issues you find, then reroof.

Lattice is not required if you have decking already. Just staple down 15 pound felt and then screw the metal directly . Lathing , lettuce or whatever you call it in your NoW is not required or needed.

I agree with Slumlord, and Kellory. Listen to these guys. Unless you tear off the shingles you have no idea what is below, or what the condition is. Once you get it done and inspected you are ready to go. Unless you already have shingles off, you really have no idea what the condition of the decking is. If the decking is OSB then use 1X3 or 1X4 strips to screw to. The manufactures of metal roofing I've seen throw your warranty out if it's not attached to plywood. IF it's 3/8 ply you have the same problem. If it's a concern to you, why haven't you talked to the company providing the metal? If you want their warranty, find out what THEY require.

It’s always best to tear the old asphalt off but, if you opt to leave it on, you’ll want to construct a cold roof.

the guy is talking about an old mobile home he camps out of......looking to keep it as low cost as possible, in this case furring strips over the shingles will work.

would I do that on my house ...no...…..kellory ..I am a general contractor....anytime someone lists 4,5,6 jobs in the trades that he does., usually means he isn't good at any of them.....bob

What year is the mobile home? Single wide?

It’s not hard to tell if you have weak spots in the roof. Is it leaking now?

Since you’re trying to save money and all, go ahead and rip out all the paneling on the inside. Better make sure there’s no termites or black mold.

Remove the shingles. Put down ice and water shield and screw a metal roof on it.

Double wide, 7 - 8 years old, 50 x 27, nice condition overall. Leaking in one spot over the door five or six feet from the dripline. Shingles where blown off in a few places and will leak when the rainy season starts in September or a tropical storm blows in, whichever comes first.

fyi - the nearest roofing supply house is 80 miles away one way in San Antonio. So it’s not like working a job in a city.

Thankfully I found a good HVAC man nearby- only 40 miles away. He does not know a single roofer anywhere close as they are working in the oil patch jobs now.

Find the closest manufacturer of steel roofs. Take him the measurements of your roof and he will custom build your entire roof including all endcaps, centercaps, screws, etc, and he will supply firring strips if you decide to go that way. My guy offers two weights of steel. He recommends the lighter weight for roofs, and the heavier for unsupported walls. I put the heavier weight on my roof for added hail resistance.

It is a couple day job for a couple of guys to install the entire roof. Absolutely NO skilled labor involved. If you can climb the ladder and get on the roof, and are smart enough to not walk off the edge, you can install a steel roof.

One warning, do not attempt to work on steel when it is wet. It gets slicker than snot. Especially with a skiff of snow on top.

Around here, we deal with "Treasure Valley Steel". I bet you have a similar manufacturer in your area. Fire up the old google-fu.

Think outside the box. Build an over-size, free-standing, metal roofed cover for the home to add a covered patio or parking area.

Ice and water shield on an entire roof deck in any climate but yours will result in rotting out your roof in turbo time.

I don't care what the requirement is, or even if there is one.

If I walk around on a shîtty, 20 yr old cooked-out mobile home roof with dry rotted 3/8" plywood on 2ft truss centers. I can assure that wimpy, crunchy 3/8" plywood isnt much of a viable medium to hold a screw driven into in it.

So, thus I "like" and "encourage" people I've done these jobs for opt for horizontal furring of 1x4 spf.

The only way I would go directly back onto bare plywood, would be if the house's attic was well ventilated to begin, the structure was 10 yrs old or less AND it had 1/2" 3ply cdx ply.

Again, check out the plywood, even better if the house rafter are on 16" centers, cover it with 30 or 15. (30 is a personal preference)

For many this is only “thinking outside the box” when taken literally.

If have seen that done too. Which, in the scheme of costs...and it being a camp house like Bobmt reminded us of.

I have a 36ft long steel carport awning over my Jayco. It was $3200 for the mexicanos from Eagle carport to come erect in 6 hours.

Why not?

I see what you mean: install the purlins and remove the decking from the equation. I absolutely wouldnt put new materials on a chitty structure either. My way assumed the decking was inspected and repaired as needed . Thats the correct way instead of leaving chit there and going over the top of it.

Oh yeah, my bad...I only did a couple dozen metal roofing jobs but I've done 500-600 other compete asphalt shingle jobs.

I realize that puts me in the "jackoff of all trades category"

Would've done more but I had a real job being a GIS Analyst for an engineering team the first 8 hours of my day.

Lol..... yes, it can mean he never figured it out, and just moved on, true. But try that when you are working for family. That general contractor is my father, the Engineer.
(And my role model)
My job was to solve problems, keep jobs moving and on time, jump into any job that needed help, and I was good at it. I gave it up to go to college, stepping down to laborer to concentrate on my studies.
I'm still a trouble shooter, a service tech in the trades, and a specialist for more than the last 35 years. But you are welcome to your opinion, sir.