Wood Structure- Top Plate Discontinuity

[xeneize10]

Good morning, I am writing to request assistance on how to deal with top plate discontinuity along a grid line due to windows placed at the location of the top plates. Suggestions on how to deal with the discontinuity. I was thinking of placing 4x blocking below the window and below the top plate and splicing with screws. thoughts? suggestions on how much the splice should be? thank you

 

[Sawbux]

Use the headers over the lower windows and doors as your continuous "plate".

 

[msquared48]

...With straps and blocking too... Sounds good to me.

Mike McCann, PE, SE (WA)

 

[CBSE]

I would use the beams, but run 3 bays of blocking beyond with strapping. Also, where your plate breaks, I would put a vertical strap there as well to eliminate any discontinuity issues.

 

[KootK]

Based on where your roof planes appear to intersect your walls, perhaps it would make sense to simply lower your top plates so that they can be continuous. You'll want some heel height at the eves for ventilation etc won't you? I feel like some poorly thought out architectural choices here have led to unnecessary complexity.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[dhengr]

Xeneize10:
Those seem like dumb Arch. details, at the expense of simple/clean structural details which are every bit as important as his artistic whim. The Arch would not lose much window area, or change the appearance appreciably if he allowed the wall top plates to be the rough sill framing for the upper windows. Argue you case a little more vigorously, that continuity is important, and those gable end walls are weak enough as it is with all the openings that exist below.

 

[XR250]

I am jumping in here late, but shouldn't those walls be balloon framed and not have a dbl. plate except at the top of the wall?

 

[msquared48]

Not necessarily if the beam over the lower windows is continuous and can handle the lateral load, and the plate to the left is braced by either kickers or a ceiling diaphragm.

But balloon framing may be the better option, depending on what we do not see....

Mike McCann, PE, SE (WA)

 

[xeneize10]

thank you all for your information. The roof is a retrofit. The roof used to have ceiling joist, reason for the double plate at that location; however a contractor made the structure vaulted at different locations and I am trying to make it comply.

 

[XR250]

Balloon frame it by cutting thru the top plate with 2x6 cont. studs from floor to roof.

 

[jayrod12]

Balloon frame it by cutting thru the top plate with 2x6 cont. studs from floor to roof.

Or similarly, built up studs on either side of the windows and a built up stud at whatever spacing allows the current double top plate to act like a wind beam. This usually results in significantly less cuts, and approximately the same number of studs.

 

[txeng91]

Assuming the first 2 on the left are vaulted ceilings (roof forms ceiling. The only way to avoid steel framing would be to have some sort of beefed up top chord on the left one to cantilever out and catch the ridge beam and have beefed up king studs between windows to transfer out of plane loads and strap any incontinuities in the top plate located at the bottom of the gable.

 

[xeneize10]

Thank you gentlemen for the valuable input. It's very much appreciated.