In view of the Green Building Program being used by some federal
and local governments the following question from AWCI’s
NetForum seems appropriate. I’d also be interested in hearing
from AWCI members and readers with additional experience
in recycling or other Green Building experiences.
Q. I would like to know if there are any wallboard
manufacturers that will take scrap wallboard
with a thin vinyl covering on one side.
A. Apparently it is up to the recycler to accept gypsum
board panels with vinyl facings. One company
I spoke with, Gypsum Agri-cycle in Lancaster,
Pa., said “It’s an ‘it depends’ situation.” Seems some of
the recycled wallboard is used for agricultural purposes as in soil
amendments and, as such, small pieces of vinyl are not objectionable.
Some facts from the California Integrated Waste Management
Board make a good argument for recycling gypsum
board. They are as follows:
New Drywall: 15 million tons each year. California uses approximately 1.8 million tons each year. This number, of course, fluctuates with the economy.
New Drywall Scrap: Approximately 12 percent of new construction
drywall is wasted during installation. California generates
approximately 200,000 tons of new drywall scrap each year.
Drywall Scrap Generators:
New Construction: 64 percent
Demolition: 14 percent
Manufacturing: 12 percent
Renovation: 10 percent.
With these numbers in mind, and the move to prevent disposing
of gypsum in landfills, recycling is a viable method of disposal
regardless of whether the project is a Green Building or
not. A couple of Web sites worth investigating are www.recy-clingtoday.com and www.cdrecycler.com.
Q. What is the minimum temperature for
installing drywall? I’m doing work for a home
builder who places the responsibility of providing
temporary heat to the home owner. Apparently the home
owners do not always understand the need to maintain temporary
heating during the installation and finishing of drywall.
—via e-mail
A. The Gypsum Association’s publication GA-216-
2000, Application and Finishing of Gypsum
Board, is very clear on this subject. Article
4.3 on page 4 addresses Application Temperature Limitations.
The items covered under this article address the temperatures
required for mixing joint compound and laminating adhesive,
application of gypsum board, joint treatment and texturing.
Addressed also is the maximum temperature when temporary
heat is used. Adequate ventilation is also required during the
installation and the drying or curing period. Under Article 18,
Finishing of Gypsum Board there is the caution that “Compounds
shall not be allowed to freeze.” In Appendix A-A.3, Precautions
to Mnimize Potential Sagging there is precaution to control the
relative humidity within the structure “by providing adequate
ventilation before, during and after gypsum board application,
and during and after activities that create high humidity after the gypsum board application… .” Cold weather is addressed in the appendix as well. The requirement states: “In cold weather, inside temperatures shall be maintained between 50 degrees F and 70
degrees. When portable heaters are used, the extra humidity that
they produce shall be removed.”
If you have any doubt that temporary heat will not be provided
in an acceptable manner, you should insist on including these
requirements in your contract. Without the prescribed heating
and ventilating conditions, you are likely to be placed in a position
where, regardless how experienced your mechanics are, the
end product will be rejected as unacceptable.
About the Author
Donald E. Smith, CCS is AWCI’s director of technical services.
