tectum

does anyone know off hand when shingle manufacturers stopped warranting their shingles on tectum decking. i know you used to be able to use the do-all lok nail

No idear... I just assumed it had more to do with the drastic fall in tectum usage than anything. Shingles over tectum with tube-locks was pretty common around here at one time. But then so was tectum. I can't remember the last time I saw tectum on a wide scale use as a structural deck.

Pre-energy crisis of the 70's tectum was sold as a structural deck, insulation and accoustical surface all-in-one. Today, the need for far greater r-values largely erases any potential benefit of tectum, cuz tectum ain't cheap.