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 A
NEW RECIPE FOR WOOD
Safer formulations for pressure-treated lumber make it a great
choice for decks and landscaping
By
Lou Manfredini
Everyone
is familiar with pressure-treated lumber. It’s that
greenish wood that doesn’t rot. It’s used to build
outdoor decks, play sets for your kids, and landscaping retaining
walls. What people are less familiar with are the chemicals
that give the wood it’s durability--in particular, the
fact that it is infused with arsenic. During the treating
process, the arsenic becomes chemically locked to the wood
fibers (along with copper and chromium). But tiny amounts
can be transferred to your skin when you touch it, especially
when it’s fresh. Lately there has been a lot of mis-information
on what you need to be concerned with when it comes to treated
lumber. Removing this product from your home is not necessary!
To date
no one has documented any long-term health risks associated
with exposure to the chemicals in treated lumber. That being
said the manufacturers of the formula known as CCA, or copper
chromated arsenate, have decided to play it safe. By the end
of next year, the chemical manufacturers announced recently
in connection with the Environmental Protection Agency, the
arsenic-containing formula will be shelved. So where does
this leave you the homeowner?
Fortunately,
with plenty of better pressure-treated alternatives to choose
from. These have the same familiar greenish tinge as the original,
and the same resistance to rot and decay, as well as the same
lifetime warranty. The only difference is that they are 100
percent free of arsenic as well as chromium (another EPA-regulated
toxin), which should give you greater peace of mind as you
install pressure-treated wood around your home.
The most
popular alternative is ACQ, which stands for alkaline copper
quaternary. This has been for available for several years
and has been used in Europe—where, interestingly, the
arsenic—containing CCA has been banned for more than
a decade. Another is copper azole, which has been more recently
concocted and is equally effective. One caution: Both ACQ
and copper azole are corrosive to bolts and nails used to
fasten the wood. To prevent this, the manufacturers recommend
using hot-dipped galvanized steel fasteners or more expensive
stainless steel ones. Anything less durable could quickly
corrode, resulting in the collapse of whatever has been built.
As always,
change comes at a cost. You can expect to pay about 15 to
20 percent more for the lumber treated with the new ACQ and
copper azole. If you build a 10 by 10 foot deck, for instance,
that might translate into an additional $100 for the new lumber.
I think it’s worth it, especially when it comes time
to sell your home and you can brag about your state-of-the-art
building materials. If your local lumberyard does not yet
stock the new alternatives, have them order the wood for you,
which is something they will do readily.
What should
you do if you’ve already have a deck or outdoor play
set built with the old CCA-treated wood? Relax. The EPA says
they have found no reason to advise ripping it out, although
you may want to consider sealing it with a penetrating oil-based
preservative. This will not only seal in any arsenic that
may leach out, but will also help extend the life of the wood.
In fact, whatever wood you use outdoors, I recommend preserving
it.
With the
right care, pressure-treated wood—no matter what formula
it’s made from—should last a long, long time.
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This article
originally appeared in USA Weekend magazine.
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