Don't Put Drywall Scraps in Wall Cavities

Don’t Put Drywall Scraps

in Wall Cavities

Dear Editor,

Thanks for your extensive coverage of construction and demolition waste in the Nov./Dec. ’92 issue (

Vol. 1, No. 3), particularly the table “Job-site Waste Suggestions by Material” on pages 7 and 8. However, within the category

Drywall, the following appears:

“Seal left-over drywall scraps into interior wall cavities. Be sure that this strategy will not interfere with future wiring or plumbing modifications.”

I take issue with this recommendation for the following reasons:

1. It would be difficult for me, a former remodeling contractor of seven years, to predict which interior wall cavities might or might not be involved in future wiring and/or plumbing modifications. A lot of drywall is hung by subcontracted drywall crews with even less information and/or interest regarding the right bays to stuff.

2. There is little or no thermal mass or acoustical benefit from the random fill of interior bays, according to a materials engineer from RTI, a waste gypsum reclamation product company, with whom I discussed this strategy. Although not cited in your article, these reasons are often offered for placing waste drywall in interior wall cavities.

3. As a resource economist, I view diversion to an interior wall cavity as a postponement of the waste disposal problem, not a solution.

I checked with the U.S. Gypsum Association and the National Association of Home Builders, and although neither organization has an official position on this strategy, both agreed with the reservations expressed above.

My interest in the disposal of waste drywall stems from my graduate research at the University of New Hampshire and Domtar Gypsum of Newington, New Hampshire. We are performing an economic analysis of the recycling of construction-site-generated drywall waste back into new wallboard. I hope within the next few months to write you about our success in analyzing all of the alternatives to disposal and economics of processing waste wallboard into new product.

There are many components of the construction and demolition waste stream whose separability, remaining utility, and high mass or volume, make disposal an economic and environmental travesty. Publications such as EBN go a long way in helping all of us involved in the building industry make the transition from “waste” to “secondary resources.”

Sincerely,

Peter A. Yost