TECU Master Seams: a primer in metal roof seaming

There is very little information in english on traditional metal roofing. This is what prompted me to begin studying seaming, and publishing the metal roofing bible in 2018 after years of study and work in this field. I found all of the American resources lacking in this department, and most of the leaders in the field of historical roofing in America lacking in their knowledge of time-honored methods for folding and seaming. This short brochure is one of the few examples that show basic seaming techniques.

Although it does not offer instruction on how to create patterns for unique situations, it gives the reader the basics of the “knots” used to accomplish different details in metal roofing without cutting, soldering, or sealants. These techniques allow the roofing elements to be free-folded, and more importantly it allows the roof to be repairable in the future without disrupting the entire assembly. This is not possible with american flat-lock methods where pans are soldered together creating a monolith.

Universal Sheet Metal Pattern Cutter, VOL2

“Surface development” or “surface pattern making” is the process of creating a 2d pattern for any shape that will be formed out of sheet material to create a 3d assembly.

The skills of surface development pattern making are important for decorative sheet metal, historic preservation, metal roofing, and copper work. Learning how to develop a pattern for any shape you would like to create can be useful for larger architectural forms as well.

One of the techniques used in pattern making is called “parallel line development”. This skill is vital for creating notching patterns for standing seam roofs.

The book, along with many other primary sources are hosted at The APT Library at the internet archive.

Learn to fold metal roofs!

In 2015 I left Rhode Island, and Casa Buena Builders to bring seamed roofing to the english-speaking world. I had been studying at night, bringing my skills up with folding and joinery; while working full-time in historic preservation, remodeling, and slate roofing. My favorite project of the tour that year was this seminar I was invited to give at the HPTC (Historic Preservation Training Center) headquarters in Frederick, MD.

Almost all of these techniques were completely foreign to the seasoned pros from the National Parks Service. I hope to one-day have all of these rules codified in English, and accepted at least internally within organizations like NPS. We may never be able to regulate the entire market like the better countries but within institutions and even preservation districts it is possible. I know all properties benefit from having roofs that are designed to last as long as the building.

This handout (PDF link) below demonstrates how to layout and cut the valley seam, from the ground as long as you know the two pitches of the intersection roof faces. This is very important with metal roof seaming. Much like in timber framing: the piece must be fully fabricated to exact specifications before they are assembled. In the same way: we do most of our design and layout on the drawing board, and on the cutting bench. There is very little “in place” fabrication, only folding assemblies.