Composite Decking
materials are expected to increase in use but everyone should remember
that the structural members used for this material will be treated lumber
and you will have the same chemical reaction happening with the structural
members, fasteners and connectors. Always before, fasteners were coated to
resist corrosion on the exposed area only for esthetic reasons. According
to the experts, we now have two changes going on with this “new treated
wood”. First, they have taken out arsenic (to protect the public) which
was acting as a inhibitor for the fastener coatings. Second there is
approximately 3 times as much copper II in some of these chemical
mixtures, which basically sets up a chemical electrolysis between the
copper molecules and any iron touching the wood, including the fasteners.
This electrolysis quickens the breakdown of the coating and intensifying
corrosion within a shorter time frame. Now everyone must actually worry
about what is happening inside the wood for structural reasons.
ACQ Lumber is Replacing CCA Treated Lumber
Why
is CCA lumber no longer being sold?
In early
2004, retail lumber dealers in the United States, began phasing in
ACQ (Alkaline Copper Quaternary) lumber to replace CCA & Wolmanized®
lumber. The Preservative manufacturers are voluntarily taking this action
based on negative public perception of CCA, media coverage and growing
consumer interest in using an alternate wood
preservative.
What
is ACQ Lumber?
ACQ is a copper based preservative system that
is the most cost-effective alternative to CCA. ACQ has been researched and
tested since the late 1980's. It was introduced commercially in 1992. ACQ
provides dependable performance and is building code compliant (NER 628).
It treats a wider range softwood lumber species, and is quality assured by
a third party (TPI or SPIB). Like CCA, it is treated against decay and
insect damage.
What
is ACQ lumber approved for?
ACQ is ideal for
structual uses, sill plates, outdoor furniture, playground equipment,
patios, decks, garden edging and landscaping structures. The preservatives
in ACQ products meet American Wood Preservers Association
standards.
Are
there different grades of ACQ lumber?
Yes. The same formula used for CCA lumber
applies to ACQ treated lumber for the following
applications:
- Above Ground (.25)
- Ground Contact
(.40)
- Fresh Water Contact (.40)
Can I use
the same metal fasteners as CCA lumber?
The chemicals used in ACQ will corrode
ordinary galvanized fasteners, therefore special consideration must be
taken when working with ACQ lumber. Hot dipped or stainless steel
fasteners MUST be used with ACQ.
