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Using Deck Screws With Joist Hangers
I have a question regarding the use of
joist hangers. I'm wanting to use a hanger ( model LUS28 made by
Simpson/Strong-Tie) to tie 2x6 joists on 16" centers with a 6' span
to a 2x8 ledger and a 2x10 rim joist. The box for the hangers says to use
a standard 10D common nail in every hole.
I would like to know if you know if I can use the following screws instead
of the nails? THE SCREWS ARE: Deck-Mate, Phillips Square-Drive screws
(#8x2.5") manufactured by Phillips fastener products. My building
inspector says that I can't use these screws unless I can find a shear
rating on them that is equal to the recommended fasteners. I've been
unable to locate anyone that can give me any information about these
screws. If you could help me that would be great.
Thank you,
Ron
I've
been wondering the exact same thing... how to find the shear rating on
screws.
That is an important issue with building inspectors, and I'm not sure
there is much supporting science behind it. A 10d nail definitely has
more cross-sectional area (and hence more shear strength) than a number
8 screw. But nails are much more invasive than screws and cause much
more splitting. And screws have perhaps 5 to 10 times the resistance to
pull-out forces, and screws are much less likely to loosen over time as
wind makes the structure move back and forth (racking).
But they apply the codes, the codes are based on popular practices, and
you can't argue with these guys unless you have the proven data.
I'll point out that I have NEVER seen a screw fail in shear, or a nail
for that matter. Their code requirements probably result in
over-building by a factor of 2, or 4 or 5. But that's overbuilding in
only one aspect of construction. I have seen structures fail from nails
pulling out or wood splitting.
The manufacturer of those screws should have this info. I haven't had
time to chase them down. Home Depot should have access to this info,
since they promote those screws so much.
Bruce W. Maki, Editor.
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