1. What is CCA and how does it
work?
The chemical used to preserve Wolmanized Heavy Duty
pressure-treated wood is a mixture of the oxides of copper, chromium, and
arsenate known as CCA. The preservative has been formulated to render wood
useless as a food substance for termites and fungi while keeping the wood
attractive, clean, odorless, non-staining, and safe to handle when used as
recommended. For more information, please click
here.
2. For what applications can Wolmanized Heavy Duty wood be
used?
Wolmanized Heavy Duty wood can be used for industrial
applications. For listed uses, please click
here.
3. What are AWPA
retention requirements & Use Categories?
Wolmanized Heavy Duty
pressure-treated wood is treated to various retention levels that are intended
to protect the wood for particular applications. Retention levels indicate the
amount of preservative retained in the wood in a specific assay zone. For
more information, please click
here.
4. What hardware is
recommended for Wolmanized Heavy Duty wood?
Corrosion-resistant
fasteners should be used with Wolmanized Heavy Duty wood. For detailed
information, please click
here.
5. What are the
design values for CCA-treated wood?
Since pressure treatment with
Wolman® CCA preservative does not alter the natural characteristics of wood, the
design values for untreated lumber and plywood should be used in accordance with
the National Design Specification for Wood Construction (2001 edition), issued
by the American Forest and Paper Association.
Wood products which have
been preservative-treated are referenced in Section 4.3.14 and 6.1.4. If lumber
is not dried after treatment, or if the end use will result in a moisture
content exceeding 19%, wet service factors shall be applied (see 4.1.4 and
4.3.3).
In addition, load duration factors greater that 1.6 shall not
apply to structural members. The design values for all acceptable species and
grades of lumber are given in the Supplement to the National Design
Specification.
6. Is CCA-treated wood
safe?
The fixation which occurs subsequent to the treating process
makes Wolmanized Heavy Duty wood safe for the environment and for the individual
user when this wood is handled as recommended. Once the Wolman CCA is
fixed in the wood cells, it is highly leach-resistant. With seven decades of
usage, its harmlessness to people, plants, pets and the environment has been
documented by academic and governmental researchers and agencies.
As a federally registered pesticide, Wolman CCA preservative undergoes a formal investigation and evaluation by the Environmental Protection Agency periodically. Based on an abundance of documentary evidence, the EPA deems Wolmanized® wood to be suitable for uses described on this site (see Consumer Safety Information Sheet). Other agencies also oversee aspects of the production, transportation, and use of CCA and CCA-treated wood. Material Safety Data Sheets are available from the treating companies licensed to manufacture Wolmanized Heavy Duty wood.
7. What are the environmental
benefits of Wolmanized Heavy Duty wood?
Unlike plastics, steel, and
concrete, Wolmanized wood is made from a renewable resource grown on managed
timberlands. It requires less energy to produce than plastics and offers greater
insulation value; and, because of its lighter weight, preserved wood can often
be installed with lighter equipment which has less environmental impact.
Wolmanized Heavy Duty wood also contains copper derived from recycled sources.
For more information, click
here.
8. How is Wolmanized Heavy
Duty wood produced?
The basic treating process is simple and highly
controlled.
| 1 — Lumber, timbers, or plywood is loaded onto small rail or tram
cars. The trams are moved into a large, horizontal treating cylinder. |
| 2 — The cylinder door is sealed and a vacuum is applied to remove
air from the cylinder and the wood cells. |
| 3 — Preservative solution is then pumped into the cylinder. |
| 4 — The pressure is raised to about 150 pounds per square
inch, forcing CCA into the wood. Treating time varies depending on species of wood, commodity being treated, and the amount of preservative to be impregnated. |
| 5 — At the end of the process, excess treating solution is pumped
out of the cylinder and back to a storage tank for later re-use. |
| 6 — A final vacuum removes excess preservative from wood
cells. The cylinder door is opened and the trams are pulled out. The wood is wet, so it is kept on a concrete pad until any dripping ceases. |
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