Hidden Deck Fasteners - Continued
Deck Clip — DC50
The instructions for this clip tell you to "Fasten the first
deck board onto the joists by toe-nailing up through the joist
below into the deck board. Be sure no sharp points protrude
above the deck surface." Well, I suppose that's one way to do
it, but not the way I would. To attach subsequent deck boards,
you nail DC50s onto the inside board edge, positioned 2 inches
to one side of each joist. Move the deck board into position,
sliding the DC50's lip under the previously laid deck board.
There's no connection between clip and joist; you toe-nail the
deck boards' outside, or leading, edge to the joist.
The DC50 is the
only edge clip that doesn't provide a direct
decking-to-joist connection. Instead, the clip's
protruding metal lip slips below the preceding board's
leading edge, off-set from the joist, preventing uplift
at the inside edge of the next deck board.
The concept behind this clip is to make square-edge lumber
behave like tongue-and-groove stock. By jamming the protruding
metal lip under the preceding board's toe-nailed edge, the
inside, or back, edge of the board is held down (see the
illustration above). Perhaps more accurately put, the clipped
edge resists uplift. A source at the company (see "Fastener
Manufacturers," page 4 of article) informed me that most people
go back and screw the deck down after five or six years of
service. (He added that the DC50 has been around for about ten
years.) It isn't that the deck boards are in any danger of
coming up, but with lumber shrinkage comes a slight looseness
and rattling underfoot.
Made for lumber that is a minimum 1 1/8 inch thick —
which may rule out a lot of so-called 5/4 stock — the
DC50 has a pair of raised dimples that provide uniform spacing
between boards, but you can also ignore them and adjust the gap
for irregular board widths.
Because there is no direct connection between the clip and
joist, the decking rests directly on the framing. This makes it
feasible to use a good, exterior-grade subfloor adhesive under
the decking to compensate for the eventual "loose" effect. But
you take that approach at your own risk.
The DC50 comes in boxes of 50 for $9.20 (about 18¢ each)
making this the least expensive system available. You'll need
2.5 clips per square foot of decking.
The Dec-Klip measures 2x1x7/8 inch overall. The 7/8-inch
height makes the clip unsuitable for decking thinner than 5/4,
assuming minimum 1-inch-thick stock. To install the
electroplated galvanized-steel Dec-Klip, you toe-nail a 10d
galvanized box nail through the clip's upright neck into the
edge of the decking board and the joist below. There's an
elongated slot in the clip to accommodate the angled
The approximately 3/32-inch-thick clip has a bi-directional
tongue that rests on the joist underneath the deck board. This
tongue elevates the decking board above the joist and
encourages complete air-drying by eliminating direct contact
with the joist. (You shim the first board level using a flat
washer of equal thickness to the tongue.) The tongue fastens to
the top of the joist with an 8d box nail. The manufacturer
suggests using #6 drywall screws as an alternative to the 8d
nail, but this is a suggestion I'd avoid. Brittle, rust-prone
drywall screws are suited to one purpose only, and there are
some good, durable deck screws available now.
Dec-Klip has a bi-directional base that elevates the
decking board and encourages complete air-drying by
eliminating direct contact with the joist.
A 7/16-inch-long, sharp prong projects from the neck of the
installed clip. The next deck board is forced onto the prong,
either by driving the board with a heavy maul (remembering to
protect the board's edge with a scrap of wood), or by using a
specialized levering tool known as a BoWrench (Cepco Tool;
Whichever way you move the board into position, it's important
to keep the weight of your body on the board to avoid
misalignment. The prong is the only connection holding the far,
or blind, edge of the decking down in place. The manufacturer
admits that hard lumber species such as Ipe can be a real
challenge, so you may want to consider using a different system
when working with hardwoods.
The 3/32-inch-thick neck of the clip establishes the gap
between boards. Such a narrow gap may not be adequate for
lumber that swells when wetted. Perhaps a greater concern is
shrinkage; when typically wet pressure-treated lumber dries
out, the gap could become wide enough to release the 7/16-inch
prong. For this reason, the manufacturer's literature warns
that your decking lumber should be fairly dry before
Butt joints. Because two
clips can't share a single joist location, you should use the
longest lumber available to reduce the incidence of butt
joints. Where joints do occur, you'll need to sister a length
of framing material onto the joist to support the clip for the
continuing board. Randomly sistered joists may not look so good
from the underside of an elevated deck.
The literature states that you'll need about 2.53 clips per
square foot on a deck with 16-inch joist centers and
31/2-inch-wide decking. A box of 200 clips costs $50, or
25¢ each. The price drops to 20¢ per clip for
purchases of six or more boxes. A 16x24, 384-square-foot deck
would require five boxes of clips.
This bottom-fastening 22-inch-long, T-section bracket attaches
to alternating sides of each joist with the provided #8x1-inch
screws. The top flange flares out to catch the decking before
doubling back to rest on the joist's edge, creating a small gap
between decking and joist.
The Deckmaster track is attached
to alternating sides of each joist before fastening it
to the decking. Deck boards are connected by reaching
underneath and screwing upward through the perforated
There are 23 joist and deck screws combined per
track-length, which translates to 12.5 screws per linear foot
of track installed. That's a lot of screwing and, when working
with dense, hard decking material, possibly predrilling, too.
The included screws do have self-drilling tips. The
manufacturer suggests preparing the top of the track —
which comes in galvanized- or stainless-steel — with
black spray-paint to reduce its metallic glare between deck
boards on sunny days.
To calculate the number of brackets needed, multiply the
linear footage of the deck joists by 12 and divide by 22. On
16-inch joist spacing, you'll need 2.5 brackets per 25 square
feet of deck surface. A case of 100 galvanized brackets and all
necessary screws costs $251; that works out to about 25¢
per square foot. Stainless steel brackets cost $451 per 100.
Because the track is fastened to the joists first, you'll want
to plan the occurrence of butted decking seams ahead in order
to provide fastening at both sides of the joint.