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Re: Plywood shear walls with 3x sills...

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Another option is for the lumber yards to rip 4x6 PT into 3x4's.

----- Original Message -----
From: "Robert Shaffer" <rkdn(--nospam--at)>
To: <seaint(--nospam--at)>
Sent: Saturday, December 04, 1999 11:54 AM
Subject: Re: Plywood shear walls with 3x sills...

> As a builder as well as an engineer,  there are certainly some logistics
> problems associated with 3x materials.  I performed a random survey of 3
> yards.   One I deal with regularly and two others in the San Jose Area and
> these are the results of my mini survey:
> Did they have 3x4 in stock?   All three said no,  but one of the yards
> to run it immediately for me.
> How soon could I get a Unit of 3x4 ?   All three cold have a unit
delivered to
> my job in three working days.
> How much for a Unit of 3x4 ?  None would give me a solid quote until they
> with the Mill,  however when I pushed a little I was told by one yard that
> would be around $  600.00 per MBF ( 2x4 was quoted @ $ 480.00 )  That
> to a 25% cost increase for the few 3x members which may be required.
> I know that 3x pressure treated is stocked by most commercial lumber yards
> it was quoted @  $ 1150.00 MBF.   Expensive,  but typically not much is
> required.
> >From a buildability standpoint,  the 3x stud makes layout more
> increases is the weight of the wall you have to lift and adds one more
thing to
> the growing list components that need to be purchased.  All of these I see
> more of a nuisance than real problem.
> A 3x sole plate for a stud wall is a little tougher,  I have not seen 30d
> for a pneumatic nailer,  so the sole is going to be hand nailed from the
> or toe nailed.   I can see this as real a problem for the production
framers on
> big tracts,  but does not have a huge impact on custom residential.  I
> always used 3x p.t. for mud sills and ledgers.
> So, IMO,  tell the contractor to stop whining about it and get on the
> yards to stock 3x .  Careful detailing to avoid abutting plywood panel
> nailing of the walls will reduce the amount of 3x required as well.
> Robert Shaffer, P.E.
> Santa Cruz,  CA
> Peder and/or Cathy Golberg wrote:
> > >
> > >
> > >3.  I've had some contractors whine (no...really?) about this, saying
> > >they either cannot get 3x pressure-treated members or they are very
> > >expensive. Some building officials also are not enforcing this
> > >(no...really?). Anyone run across this?
> > >
> > >
> > >Dave K. Adams, S.E.
> >
> > I'm going through this right now at the moment also, including the whine
> > part.  Based on the added weight??, cost, material availability, etc,
> > contractor has pleaded with me to use 2-2x members instead of the 3x or
> >  He has gone and recieved approval from the building department to do
> > as long as he can show a letter from the EOR (me) it is okay.  At the
> > joints, I have agreed to allow multiple studs joined with the same
> > as the plywood panel edges (studs built-up with 10d at 2" o/c staggered,
> > e.g. 2 rows of 4" o/c) as I don't see this any different than shear
> > transfer at a typical top plate on a wall that had 10d at 4" o/c edge
> > nailing.  I told the contractor I thought they were crazy with the added
> > labor and materials and that the 3x or 4x had to be cheaper in the "big
> > picture" than his proposed method (penny wise, pound foolish?).
> > it is cheaper as the 2-2x is still their desired plan.  The only thing I
> > can figure is that the framers don't know the panel edge locations until
> > later and think they can add the 2nd stud after the wall is erected.  I
> > think this will be interesting to observe during construction.
> >
> > I have, however, not given into using 2-2x plates at the sill.  They
> > to use a P.T. 2x with a 2nd 2x nailed on top (2 rows of 10d at 4" o/c)
> > the anchors extending through both plates.  I seem to remember seeing
> > failures of the A.B. pulling through 2x plates which has something to do
> > with the 3x requirement.  I'm not totally sure if I'm being consistent
> > my reasoning.
> >
> > Any thoughts on using built-up 2-2x members instead of the 3x member??
> >
> > Sincerly,
> >
> > Peder Golberg, P.E.
> > Portland, OR
> >