Curbside Maintenance: Installing A New Steel Roof, Solo

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– Posted on June 2, 2022

This was my first moved house, which arrived here in late 1996. Its asphalt shingle roof was already quite old at the time, but I do not believe in replacing a roof before it really, truly needs it. I constantly see houses getting roofs torn off for a new one that I would have kept at least another decade or two; money thrown away. That’s just me, but the reality is that asphalt roofing shingles almost never leak from just age; it’s invariably at some joint, roof penetration, chimney or transition.

I’d been procrastinating about this one for a number of years; the shingles had shed much of their gravel and were drying up, curling, breaking off in the wind, and otherwise showing signs of severe aging. My guess is that it was well over 40 years old, and these were just cheap, basic three-tab shingles.

I much prefer steel roofs (galvalume-coated steel panels), and have used them on numerous sheds, additions, a small cottage and part of our own house. But this was bigger (~1600 sq. ft of roofing) and more complex. And I didn’t have a helper, so I girded my loins and plunged in (more like jumped up), despite an unusually wet late spring.

The beauty of these steel panels is that they can be laid down directly over the existing roof; there was no way I was going to tackle a tear-off, even with help, given the repeated rains, never mind the cost of it. Here I am starting the south side; the poor condition of the formerly-white shingles is obvious. You can see where I wove in some new shingles where the chimney had been, as well as the new ones in front, over the porch I added at the time (1997).

I thought I might be able to walk on the 5/12 pitch roof to pull the panels up, but because the gravel was either gone or very loose, I couldn’t, reliably. So I had to break down and order a $37 ladder hook, which secures the ladder at the peak. I just propped one of the 13’9″ long panels up against the step ladder and the eaves, then climbed up on the roof (from the other side, which had a low-slope section), walked down the hooked ladder and pulled up the panel and dropped its leading edge ridge over the trailing edge ridge of the previous panel, which is how they overlap without leaking.

I worked whenever there were breaks in the weather, since it didn’t matter if it rained in between. Any water that got into the underside of the panels at the ridge would just work its way down underneath the ridges in the panels. And if it’s still there, it’ll escape as vapor out through the ridge cap (installed at the end) when it gets heated up by the sun.

If you look carefully, you can see the curvature of this old roof, whose rafters are…2x4s.  Yes, that was all-too common back then on these smaller, modest dwellings. When they say “they don’t build them like they used to” I say: it’s (mostly) a good thing. But what’s a bit of curvature? My back is starting to get a bit too. The steel is very light, and since the shingles have lost most of the heavy gravel, the overall weight is very modest.

Here’s how it looked with all the panels installed, which are screwed directly to the wood deck with special screws that have neoprene washers. This is what has been used for many decades on a gazillion industrial and commercial buildings, pole barn shops/garages/barns, and on residential houses. Yes, a standing seam metal without exposed fasteners looks a bit more refined, but I just haven’t gotten around to working with it yet. This Delta Rib material is cheap and expedient.

Speaking of, my procrastination had a substantial price. When I first measured this roof and got a price for the materials about three years ago or so, it was about half of the current inflated price, which totaled to about $2900. Still less than two dollars a square foot. Installed by a contractor? You might well just add a zero to the right side of that number, in the current environment. “Were booked out to 2025…”

The last step was the one I was least looking forward to: cutting the existing roof and wood decking and skip sheathing at the peak for the venting roof cap, which allows the hot air to escape and creates a conductive draft, sucking in cool air from the soffit vents. I had to straddle the roof, sitting on a piece of rubber fatigue mat, and cut away with a circular saw. A chisel came in handy on a few occasions.

The reflective quality of this material will keep the attic much cooler too, especially compared to all the black and dark shingles that are so in vogue now. It’s the worst possible color choice, given that they will heat the house as well as themselves to where their lifespan will be materially shorter.

The cap is designed to prevent water intrusion except under the worst storms with very strong wind, so I bent up the ends of the panels to prevent water being blown uphill from getting into the open attic. If a few drops make it in, it’s not the end of the world either. What damages wood is continual water contact, not a random splash once in a while.

Here’s the ridge cap in place. It has a 3/4″ deep opening between the ribs. The plumbing vents require special seals, which have a flexible base that conforms to the ribs in the roof, and is screwed down all the way around.

It took me some two weeks to do this, but that was very part time, given the recurring rains and the fact that I only worked about 4-5 hours per day when it was dry. I do not let myself get tired working on a roof; one little misstep can be…problematic, at best. Putting down the panels goes very quickly; two people, or one ambitious one could do that in one day. Cutting and trimming the gable end trim and peak cap and other details took a bit of time. Doing it solo also made it take longer, as I had to get down and then back up on the roof for each panel. I’ve seen Youtube videos where a crew slaps out a pretty good sized house in a day.

I’m very happy with the result; it should last 60-80 years or more. Lots of old barns hereabouts have galvanized roofing that’s undoubtedly over a hundred years old. It’ll certainly outlast me by a long shot. And no more moss growing on the shingles.