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Trusses Slightly Too Short

M

mauromj

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Joined
Jun 4, 2022
Messages
9
Location
Pullman, WA
I am building a 40x60 2x6 stick frame shop. The foundation crew poured my walls at 40' 2" x 60'. Unfortunately, my trusses have already landed and they are 40' on the dot.

What options do I have to make these work?

I can think of the following 2 options:

1. Place a third "top plate" on my ridge cap. I am thinking a 1/2" x 4.5" strip of plywood all around the top would do. I don't need much height to get my truss tails to clear.

2. Notch (birds mouth cut) the top chord of the truss. Again, I wont need much here. The notch would be 1" long, by 1/2" or so in depth. Very minimal for my 2x6 top chord. It would be barely noticeable, and I am sure it wont affect the structural integrity of the truss by much (if anything at all).

Would both solutions meet code in WA state? What would you do if you were framing it?

Here is a picture illustrating both options.

freeimage.host

IMG 2793

Image IMG 2793 hosted in Freeimage.host
freeimage.host freeimage.host
 
Do not modify the trusses without signoff from the truss manufacturer.

You might thicken the exterior walls. This would allow the supporting wall to be where the trusses want it. You could then furr the exterior wall to match with the edge of the concrete. This change should be submitted to the building department as a modification
 
I assume your walls are built. I'd ask truss manufacturer but the plywood idea or just another 2x6 set in 1" would seem simplest.

If the truss will span the extra 2", would it be simpler to chamfer the top plate than notch every tail?
 
The truss manufacture would be your best and really your starting point.

But from your diagram, I will take a "WAG" here and if you set your "Skill Saw" on the degree of the truss and cut the outer edge of the top plate of the wall it should rest clean, but the cord length between walls is 2-inches longer and that needs confirmation from the truss manufacture that the span and loss of 1-inch of bearing on each side changes anything, not an engineer so only taking a "wild a$$ guess" here.

The other option if the 2-inch additional span is a deal breaker, maybe adding a 2x8 with the outer edge chamfered to accept the truss will work, by adding the additional top plate in theory would extend to the outer wall edge and inward more than the 1" of loss and allow, at least again in theory, not proven, a path for the load.

Just spit balling on the wall, the Truss manufacture is going to provide you with the best options, pretty sure they have run it to this before, at least I can't believe you are the first person to have this happen.

And your plywood option might be there solution too.

Good luck
 
Have you discussed this with the GC? It's his problem. Regardless of the foundation size, the walls should have been framed to the correct dimension.
 
Truss manufacturer can provide a solution. Do NOT attempt a half-a$$ed solution on your own. Truss folks will disown the package, and you are stuck with it.
 
mauromj said:
I am building a 40x60 2x6 stick frame shop. The foundation crew poured my walls at 40' 2" x 60'. Unfortunately, my trusses have already landed and they are 40' on the dot.

What options do I have to make these work?

I can think of the following 2 options:

1. Place a third "top plate" on my ridge cap. I am thinking a 1/2" x 4.5" strip of plywood all around the top would do. I don't need much height to get my truss tails to clear.

2. Notch (birds mouth cut) the top chord of the truss. Again, I wont need much here. The notch would be 1" long, by 1/2" or so in depth. Very minimal for my 2x6 top chord. It would be barely noticeable, and I am sure it wont affect the structural integrity of the truss by much (if anything at all).

Would both solutions meet code in WA state? What would you do if you were framing it?

Here is a picture illustrating both options.

freeimage.host

IMG 2793

Image IMG 2793 hosted in Freeimage.host
freeimage.host freeimage.host
Click to expand...
Do I understand that you believe that with the 2 extra inches of width, you don't think you have enough bearing on a 2X6?

Not sure how you would believe that, but if you really want to have the trusses align with the outside framing Then why not make the walls 1 inch out of plumb? I think you are over thinking this
 
Genduct said:
Do I understand that you believe that with the 2 extra inches of width, you don't think you have enough bearing on a 2X6?

Then why not make the walls 1 inch out of plumb? I think you are over thinking this
Click to expand...
I think the problem is that the trusses won’t set down on the top plate. If you look at the sketch, the underside of the top chord overhand hits the top plate before the bearing surface of the bottom chord.

Out of plumb walls on purpose. Sorry, that’s a dumb idea. Better to move one wall in 2” and keep it plumb.
 
e hilton said:
I think the problem is that the trusses won’t set down on the top plate. If you look at the sketch, the underside of the top chord overhand hits the top plate before the bearing surface of the bottom chord.

Out of plumb walls on purpose. Sorry, that’s a dumb idea. Better to move one wall in 2” and keep it plumb.
Click to expand...
OH DUH I didn't see the sketch. I was just trying to be funny because I couldn't believe the problem described was a real problem

So add a 2X4 on top and you have your clearance OR a better solution would be to make a 45 deg cut on the top plate
There is no question you have enough bearing

PS it sounded like the walls were 2 inch too wide 40'-2" right
 
Thanks for all the suggestions. The stem walls are poured at 40' 2" and cannot be moved. The options listed above (or the third option of 1" out of plum walls on the front/back) are my only option. Im thinking the 4.5" bearing solution is my best bet. Ill check with the truss engineer in the AM. Thanks.
 
back to my original suggestion....quick check with the truss manufacturers for a simple solution
 
fatboy said:
back to my original suggestion....quick check with the truss manufacturers for a simple solution
Click to expand...
The truss company will tell the contractor to hire an engineer. If he lets the truss top chord into the top plate it will be no harm, no foul.
 
I would think a simple ledger on each side wall would bring it in 3" and make for adequate bearing......Wait...saw the sketch....They might let you nip the tail and I would assume you don't need more bearing than a 2x4 plate, but it might depend on snow load and if you have a room inside the trusses....Truss manufacturer...
 
The truss paper work should indicate the required bearing or the bearing presented to the truss designer. It is possible that the truss software can use a lessor bearing and still work but the issue needs to be presented to the truss designer for calculations.
 
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