maximum number of top plates

[jhalvorson]

I have a framer who used 6 2x6 top plates around for all the exterior walls instead of two. He also used 4 top plates on on a steel beam instead of one. How many top plates are reasonable for each condition?

 

[Tmoose]

Sounds like the studs and posts were delivered 4 X 1.5 = 6 inches too short.

What is the detail at floor to floor junction? Are some kind of metal ties going to be installed to handle uplift etc?

 

[BSVBD]

Over twenty years ago, when i was "over-analyzing" the double top plates supporting 24" oc roof trusses spanning over 50', (all design loads considered for this area in Wisconsin) i discovered that the double top plate calcs failed to support a roof truss point load at mid-span of the 16" span from stud to stud.

I was new to engineering, but, i had reasonable evidence that the traditional double-top plate was not sufficient. My supervisor approved, the contractors could not argue, and a triple top plate has been the norm ever since, for trusses spanning over 48'.

To answer the OP, I realize it is a vague answer, but, the number of top plates required is determined by whatever the design engineering requires. Without project details, i can't answer better than that. I do recall specifying to add (1) top plate in a situation to solve differing heights. but, I've never seen a need for as many top plates as you describe.

(4) top plates on a steel beam sounds unstable and unreasonable. The (6) top plates on a wood stud wall "could" be stabilized, to some extend, by the sheathing. You must decide that.

As Tmoose suggested, perhaps there was an error? This should be obvious through very little investigation.

Unfortunately, it sounds like you may have a problem to solve. Please keep us posted if you have time.

 

[jhalvorson]

Unfortunately I am dealing with a framer who took it upon himself to ignore our structural drawings completely. I am making him remove the 6-2x top plates and add full ht studs since we have some large window / door openings. However with the top plates on the steel, the framer has 1 top plate then added 2 layers of 1/2" OSB and placed an additional 2x top plate above that. The steel beam is supporting the second floor and roof which is inset from the exterior walls. The framer attached the single top plate with p.a.f. as we have called out on our plans then attached the remaining members together with 10d nails @ 8" o.c. I should also mention that the beam is 8" wide with a 2x6 stud wall and the floor joists are attached via top mount hangers. So... the floor is on and already sheathed. Looking for any advice on whether we should pack the web and strap everything together or have them demo and do it correctly.

Thank you for your help!

 

[XR250]

6 top plates will also shrink alot more than a vertical stud.

 

[EngineeringEric]

The OSB Layers worry me... Why do this!?!