Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Lag screws in withdrawal from end grain

[Subject Prev][Subject Next][Thread Prev][Thread Next]
First, your solution with the perpendicular locking pin is similar to what I
proposed, but I like your idea better. Mine used a "flitch plate" type of
connection where the plate is approximately 9.5" x 1/4" x L long (this needs
to be worked out for end distance which I think is around 7 bolt diameters).
Simpson has a connector which they introduced last year for heavy timber
connections that does something like this. You idea is similar to a
furniture connection which locks legs and edges of a table to the top with a
smooth rod inserted into a hole and intercepted by a locking nut. I think
your idea might work very well, although you may check out simpsons
connector. Simpsons product is meant to be hidden from view so as not to
disrupt an aesthetic wood to wood connection.

I mentioned the List meeting, but did not figure anything formal - more of a
social get together. I would be imposing on AF&PA to suggest such a thing. I
think I am going to arrive the night before, but I still have to make the
reservations and find a hotel. It would be a nice idea for List reunions and
could help these seminars by improving attendance.

We have a very special virtual community on our list. Like pen pals, it
would be exciting to have everyone in one place to finally meet.

Nels, you also owe me a visit so I'm hoping you will make it. We never did
get together part way between the desert and Pasadena so I'm looking forward
to seeing you there.


-----Original Message-----
From: NRoselund(--nospam--at) [mailto:NRoselund(--nospam--at)]
Sent: Monday, September 07, 1998 2:34 PM
To: seaint(--nospam--at)
Subject: Re: Lag screws in withdrawal from end grain

Dennis, those are some good ideas.  Thanks.

The condition consists of two 10x10 roof beams of a house porch, one at each
side of the porch,  that are connected to the house only by their bearing on
cripple-studs in the wall.  I have an opportunity to secure the ends of each
10x10 to a newly plywood-sheathed shear panel on existing interior
that align with the supported end of each 10x10.  The design load would be
strictly the tension of a seismic force due to the porch roof tending to
away from the house.  My thought had been to use a 1/2"x12" hanger bolt: lag
threads on one end screwed into the 10x10, machine threads on the other end
coupled to an all-thread rod extended into the sheathed partition next to
blocking between studs, with a plate and nut against an interior stud.

You are correct there are other means available the will not be unsightly,
only a little more costly.  A detail I have used before is one of installing
the tension rod into a hole drilled parallel to the axis of the 10x10 that
intercepted by a perpendicular hole drilled into the 10x10 (perhaps one and
half inches in diameter) and a half-round steel rod of the same diameter as
and inserted into the perpendicular hole.  The tension rod may be secured by
nut against the flat face of the half-round.  Tension in the rod would pull
the curved surface of the half-round to bear against the perpendicular hole.
The perpendicular hole may be concealed by a wood plug.  I think this is
of like your third suggested detail.

I'm still puzzled by the way the Code handled this; but I think you are
the condition should be solved in another way -- thanks for the warning
on what you saw after the Northridge Earthquake.

I really like your idea for using the Wood Solutions Fair for a Listservice
Group Meeting.  I don't know yet whether I will attend the Fair (as good as
sounds), but may show up for a Group Meeting even if I don't have time for a
day at the Fair.  I'll be watching for further details on when and where.

Nels Roselund
Structural Engineer