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Re: Design of Top Plates

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I believe that what Oshin is saying is correct.  If you have a rim
joist above the double top plate, it could carry the load from the
studs in the wall above.  You would then be transferring the load
through direct bearing to the top plates to the studs below.  The rim
joist handles the shear and bending.  The top plates are only there
for bearing.  You need to be careful though.  I've had contractors sub
blocking for rim joists, and vice versa arbitrarily.

Dan Goodrich, P.E.

----- Original Message -----
From: "Speck, Todd M" <tmspeck(--nospam--at)pbsj.com>
To: <seaint(--nospam--at)seaint.org>
Sent: Thursday, December 28, 2000 11:33 AM
Subject: RE: Design of Top Plates


> Redistribute the load to where?
>
> The load still progress down the studs,  through the trusses to the top
> plates to the studs and so on.
>
> I've seen a large number plans where the studs and trusses do NOT align
and
> no additional reinforcing is supplied.  I believe, far too often it is
> ignored.
>
>
> -----Original Message-----
> From: Oshin Tosounian [mailto:sdgse(--nospam--at)juno.com]
> Sent: Thursday, December 28, 2000 12:19 PM
> To: seaint(--nospam--at)seaint.org
> Subject: RE: Design of Top Plates
>
>
> You are ignoring the rim joist at every level that will redistribute the
> load from above. So, what you really need to consider is the load from one
> level only and check your double plate for that load.
>
> Oshin Tosounian, S.E.
> Los Angeles, CA
>
> ------Original Message------
> From: "Speck, Todd M" <tmspeck(--nospam--at)pbsj.com>
> To: "'seaint(--nospam--at)seaint.org'" <seaint(--nospam--at)seaint.org>
> Sent: December 28, 2000 5:33:07 PM GMT
> Subject: Design of Top Plates
>
>
> John Riley's ledger question brings up a question I've had for some time
> that no one I've queried has been able to answer.
>
> His "Studs are 2x6, D.Fir-Larch(N), @ 16".  Load from each floor is about
> 1100
> plf."
>
> Assuming the floor trusses are spaced at 24" o.c.
>
> My question is this: How does one justify the strength of the top plates?
>
> For quick calculations,  assuming the roof load is 550 plf you need to
> transfer 3850 plf (550 plf roof + 1100 4th + 1100 3rd + 1100 2nd) from the
> second floor trusses to the top plates directly beneath the 2nd floor
> trusses.  with trusses spaced at 24" o.c. that's a 7700 lb point load to
the
> dbl top plate.  The studs are spaced at 16" o.c. so there will be a
location
> where the truss bears at midspan of the dbl top plate.
>
> I've never had anyone be able to account for the shear and flexure
stresses
> that the dbl top plates are loaded with.   Is there something I'm just not
> seeing or do engineers somehow ignore this??
>
> All help would be much appreciated on this matter,  since I've never had
> anyone give me a decent solution to this.
>
>
>
> -----Original Message-----
> From: John Riley [mailto:jpriley485(--nospam--at)peoplepc.com]
> Sent: Wednesday, December 27, 2000 9:20 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Ledger
>
>
> For a 4-story, wood-framed, senior housing facility, the building official
> requires that the stairways be sheathed with gypboard on the outside, one
> layer of 5/8", and the gypboard cannot be interrupted by ledgers.  Neither
> will he allow the floor joists to bear on the stairway walls.
>
> Studs are 2x6, D.Fir-Larch(N), @ 16".  Load from each floor is about 1100
> plf.
>
> Can a ledger be lag-screwed or thru-bolted through the gypboard?  What I
> have in mind is a single 2x12, D.Fir-Larch(N) with the floor joists
attached
> with Simpson hangers.
>
> Are the values in UBC Table 23-III-B-1 applicable?  Modifiable?
>
> Is there a better way to approach the problem?
>
> __________________
> John P. Riley, PE, SE
> Riley Engineering
> 20 Oakwood Drive, Blue Grass, Iowa 52726
> Tel & Fax:  319-381-3949
> jpriley485(--nospam--at)peoplepc.com
>
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