Use and Care Manual
34
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Fasteners
Fasteners
MiTek
®
Product Catalog
WS / WSWH Exterior Structural Wood Screw Application
Attaching Deck Ledger to Rim Board Application
The MiTek WS structural wood screws can be used
to fasten deck ledgers to the rim board (AKA band/rim
joist) of structures to meet the connection requirements
of the International Residential Building Code (IRC). Both
the standard hex head (WS-EXT) and washer head
(WSWH-EXT) styles may be used for this purpose.
Table R507.9.1.3(1) of the 2018 IRC calls out lag screws
for deck ledger attachment and the WS-EXT and
WSWH-EXT may be used in place of the lag screws.
Installation:
1. Select the proper MiTek’s WS-EXT or WSWH-EXT
screw length. The threads should have full
engagement with the rim board with the tip
of the screw protruding and visible beyond
the inside face of the rim board member.
See Section View image.
2. With appropriate screw length selected, drive
the screw through the ledger, sheathing, and
rim board with a high torque variable speed drill.
3. Drive screw so head is rm and ush with
surface of deck ledger, but do not overdrive.
4. Repeat these steps and install the appropriate
number of screws at the prescribed edge,
end distance, and spacing as called out in
the table below and Figure 1.
≤ 6-ft ≤ 8-ft ≤ 10-ft ≤ 12-ft ≤ 14-ft ≤ 16-ft ≤ 18-ft
2" Nominal Solid Sawn 23 17 13 11 10 8 7
1" Min EWP 22 16 12 11 9 7 7
2" Nominal Solid Sawn 16 12
97755
1" Min EWP 15 11
87655
1) Numbers are based on use of 3-1/2", 3-5/8" and 5" length screws.
2) Screw spacing based on requirements of 2018 IRC Section R507.9.1.3 and Table R507.9.1.3.(1) and equivalent
spacing of 1/2" diameter lag bolts. Stagger screws into 2 rows.
3) Multiple ledger plies should be fastened together to act as one unit independent of the WS-EXT or WSWH-EXT ledger attachment screws.
4) Solid Sawn Rim Board shall be Douglas Fir-Larch (DF-L), Southern Pine (SP), or Spruce-Pine-Fir (SPF), G ≥ 0.42.
5) 5" length screw shall be used for all 2 ply 2x ledger members.
MiTek
Stock No.
Spacing between WS-EXT / WSWH-EXT Screws based on Joist Span (in)
40 psfDF-L / SP / SPF
60 psfDF-L / SP / SPF
Live
LoadLedger Rim Board
WS35-EXT
WSWH358-EXT
WS5-EXT
WSWH5-EXT
Perspective view
Floor
framing
Sheathing
Rim
board
WS-EXT or
WSWH-EXT
Screws
Deck
ledger
Tip of screw head should
penetrate
inside face
Section view
Figure 1
4" typ.
Screw Spacing
(see Table below)
1-1/2" minimum from bottom
of ledger and rim board
1-1/2" minimum from top of ledger
and rim board
3" max
Stagger screws
in
two rows
If ledger screws interfere with deck joist
they may be offset 3" max
WS35-EXT – 3-1/2"
WS5-EXT – 5"
WSWH358-EXT – 3-5/8"
WSWH5-EXT – 5"
Length
Designation
Length
Designation
Length
Designation
Head markings for identication
2.5"
3"
2"