Prepriming on Site
Instead of buying factory-primed siding, many builders
prefer to buy unfinished siding, and to prime the siding on
site before installation. That way, they have more control over
the process, and can be sure the primer is applied thick
enough. The work is best done under a roof.
Bob Lipovsky, president of Kingston Construction in Fairfax
Station, Va., likes to back-prime the siding on site. "First,
we prime everything that's not going to be visible - the back,
the ends. Then, when we get it installed, we prime the front,"
said Lipovsky. He has found from experience that if the front
of the siding is preprimed, then handling it gets messy. "You
don't want to prime the part that's facing you and make a
complete mess. When you're handling this stuff, you want to put
it right up."
According to Mark Knaebe, from the USDA Forest Products
Laboratory in Madison, Wis., "Ideally, you should back-prime
with a water repellent, such as Dap Woodlife." He says that
research has shown that a water repellent is better at
resisting water entry than an acrylic primer, and less likely
to trap moisture in the siding than oil-based primer.
Dominick Lubrano of DPL Custom Builders in Williamsburg,
Va., likes to prime both sides of the siding before
installation. On a recent job, he took the time to put on two
coats back and front, because "that way, you know what you get.
Ultimately, it's up to the homeowners to decide. I tell them
But it's certainly not an easy way to go. Lubrano watches
the weather for ideal painting temperature - 45 to 50 degrees -
and pays attention to the cleanliness of the workplace. Storing
the primed siding becomes a major issue. "We had to build
drying racks for 8,000 linear feet of siding to store the
lumber between coats."
Lipovsky agrees that drying set-ups take up a lot of space
He recommends spacing the boards just enough so they're not
touching, but air can still get to them. At a new home site,
says Lipovsky, it's sometimes possible to rig drying racks on
tarps in a basement, but it's rare to find enough indoor drying
room on a remodeling job.
Wayne Whitelock of Calais, Vt., prefinished the red cedar
clapboard for his own house by dipping each board in a
site-built trough filled with oil-based stain, and drying the
siding on indoor racks. He says the system worked well. The
only problem was that he ran short of prefinished siding before
the job was over. A small portion of the siding was installed
undipped, and received a coat of brush-applied stain after
installation. Eight years later, Wayne can spot the difference.
"The siding we dipped is absolutely flawless, but the
hand-painted siding is starting to lose its color. Dipping it
really does make a difference."
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