Historic Metal Roof – From Scratch!

By: Bill Kibbel , Contributing Writer
In: Old House Construction, Home Improvement Tips

I wanted to install a standing seam metal roof on my porch. I’ve repaired and restored them, but I’ve never installed one.  From inspections, I had a pretty good understanding of installation practices that work. I also study and research historic building materials and methods as part of my career - and for fun.  I have a nice collection of old books, some with great illustrations.

Looking at prefabricated, pre-finished roof systems, I found that the material cost would significantly exceed $1200.00.  I also didn’t like the look of the seam profiles or the surface finish of the factory applied coatings.  I couldn’t find anything that would closely resemble historic standing seam roofs.

Then I got an idea – I’ll make my own.  How hard can it be?  I’ve seen illustrations of guys over 120 years ago, fabricating entire standing seam roofs with nothing but cast-iron seaming tongs.

Now, I have to admit that I’m the type that has to figure stuff out AFTER diving into a project.

The first step was to get materials and tools.  My goal was to see just how little I could spend.  I bought 2 rolls of 20″ terne-plated steel on Craigslist for $50.00.  I had to drive about 25 miles each way to pick it up.

Then, I had to make a bending brake.  You can rent one, or borrow one from a contractor friend, but they’re now mostly all for bending thin gauge aluminum.  I found some very detailed plans posted by Dave Clay of Texas at www.ch601.org/tools/bendbrake/brakes.pdf.  Mine came out to be a basic, disposable version made out of 1 piece of angle iron, 2 heavy duty hinges, some nuts and bolts and some 3″ thick oak boards.  I needed 6′ long pans, so I made the brake just a little longer.

I then purchased a 9″ hand-seamer (for around $30.00 on Ebay).

With tools and materials collected, I was able to rather quickly form the 14 pans, eave/drip edge, rake trim and cleats.  Here are some links that illustrate important details:

chestofbooks.com/home-improvement/woodworking/Constructive-Carpentry/83-Metal-Roofs.html

www.copper.org/applications/architecture/arch_dhb/basic_details/joints_and_seams2.html

www.esemachines.com/resource_forming_1inchstandingseam.htm

www.esemachines.com/resource_forming_dripedge.htm

I laid out all the panels and accessories to be sure everything would fit.  I then took it all up and proceeded to secure each pan with 4 cleats.  Using the seamer, I crimped each standing seam and the lower edge of each pan to the eave/drip edge.

I finished the roof by applying 2 coats of Tin-O-Lin, a linseed oil based paint with iron oxide pigment.  This is not only historically accurate, it’s the manufacturer’s required primer for raw terne-plated steel.

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