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Building for Deconstruction: Three Things to Avoid

Published on: Jan 20, 2023

While preparing to write January’s Velvet Crowbar, I decided to do some internet research. When I conducted a Google search on Design for Disassembly, the first full page of references included the titles, “Design for Disassembly and the Environment,” “Design for Disassembly and Deconstruction: Challenges and Opportunities,” “Design for Disassembly: Themes and Principles,” “Design for Disassembly (DfD),” and “What Is Design for Disassembly?,” followed by eight additional listings. All were scholarly and quite informative; however, none cautioned the use of glue or spray insulation.

This is nothing new. I’ve been reading articles like these for 30 years, as both builders and demolition associations awakened to the benefits of building-material salvage, deconstruction and reuse. However, very few have questioned how to stick things together for easy removal. And today, hundreds of internet videos show various methods of building and repair work using techniques and products that defy salvage and reuse. Such disregard is not only puzzling, it’s shameful.

About 10 years ago, TRP deconstructed a home in Aspen. The owners wanted the random plank hickory floor (about 2,000 square feet) salvaged for reuse in their new home. Unfortunately, it was glued to the subfloor. And to make matters worse, the plywood subfloor was glued to the joists. The general contractor suggested that the flooring and subfloor be cut out together in 4x8 foot sections, and the owners agreed. With considerable effort, this process was accomplished, but even with careful cutting we lost most of the 2x10 joists.

TRP recently completed a 5,000 square-foot deconstruction and ran into this problem again. The first floor had been remodeled, and the replacement wood flooring included walnut in the main portion of the house and maple in the bedrooms. Both were glued to the 1&1/8 plywood subfloor. Consequently, we lost both the finished floor and the subfloor. Fortunately, the subfloor was not glued to the joists. From the second floor, which was not remodeled, we salvaged 2,000 square feet of oak flooring and the plywood subfloor.

As a substitute for glue, think about using 15 pound felt or, better yet, cork as an underlayment. Even better, how about floating floors of engineered wood? It is no more expensive, yet easier to install and much easier to repair (try repairing glued tongue–and-groove flooring).

Then there’s the problem of spray insulation, which complicates the salvaging of windows when it is sprayed between the frame and studs. Time spent cleaning off this stuff doubles the amount of time spent salvaging the windows. Besides the windows, all we are left with is a pile of spray insulation, which even after a thousand years will still be there —in the landfill.

Bricks are great and there is quite a market for used ones. But I do not understand why, in walks and patios, they are set in concrete. Concrete is like glue. With the same effort and less cost, bricks can be laid in sand, assuming it is properly prepared. Don’t even think about recounting the effects of ground movement or moisture as an excuse for using concrete. As a kid, I worked on a couple of long brick driveways in Cleveland using only sand as a base, and the driveways lasted over 40 years, in high humidity, lots of rain and below freezing temperatures (which, by the way, is one reason I now live in San Diego).