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Ledger to stud connection

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Charles  Greenlaw wrote:
"Checking theoretical values of small diam lags seems rather esoteric, =
given their low listed values and high demands on construction labor =
time and workmanship to correctly install them, compared to those 1/4 =
inch SDS self-drilling screws from a familiar proprietary source. Lags =
lag way, way behind as last resort in my designs, for all these reasons.
=
Same for traditional wood screws, another installation bother.   --C.
G."

----- Original Message -----=20
Drew Morris wrote:
"I noticed in the 2001 NDS (Table 11J) that the value of a 3/8" lag
screw =
through a 2x ledger (Hem-Fir side member) into a stud (also Hem-Fir)
is=20 zperp =3D 120#.  In Table 11N, the value for a 16d nail in a
similar = setup=20 is 122#.  Why such a small difference in values with
such a large=20 difference in dowell diameters?  I am planning on
checking these values=20 using the yield limit equations tomorrow."


The other good reason to shy away from lag screws is that in my
experience, the smaller ones often break upon installation, right where
the threads start.  No matter how carefully the pilot hole is drilled,
1/4 inch lags seem to break over half the time, and 5/16 inch break
often enough to worry me.  If I need to make the jump up to a lag screw,
I make them at least 1/2 inch.

Mike Hemstad, P.E.
TKDA
St. Paul, Minnesota

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