Just got house plans made up. The sill plate seems to have a 2x6 laid over top a 2x4 embedded in the foundation wall. I have searched the Canada build code and can't find any reference as to why it's done this way and not just a 2x6 sill plate bolted to the foundation. Can anyone explain why it's done like this?
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Sill plate foundation connection
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matt11
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Just got house plans made up. The sill plate seems to have a 2x6 laid over top a 2x4 embedded in the foundation wall. I have searched the Canada build code and can't find any reference as to why it's done this way and not just a 2x6 sill plate bolted to the foundation. Can anyone explain why it's done like this?
![Image]()
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No idea, we almost always do a double sill plate here. It helps with uplift and shear strength. Double row of sheathing nails staggered every 3".
But it's always double 8s, 10s or 12s, they don't offset with a smaller plate below.
I'd be concerned about the J- bolt being way off center in the sill. That has to be center third around these parts.
What's your trade?
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Does this house have brick for the exterior anywhere needing a brick shelf? I see no reason for that detail and request a RFI. Like Arrow said the bolt needs to be in the center 1/3rd. I have seen guys fail for having them too close to the outside.
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Only see 2x6 sills here unless some type of foam on the exterior. I can't imagine 2x12 plates here, would need 2 bolts every foot to keep em' flat.
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Your best bet is to get answers to "why this is the way it is" by contacting the architect and having him explain it.
That said, I don't see the anchor bolt size and the embedment depth unless it is noted on the construction detail sheet, under the concrete detail section.
That said, I don't see the anchor bolt size and the embedment depth unless it is noted on the construction detail sheet, under the concrete detail section.
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We have a lot of ICF foundations here with 2.75" foam on the exterior and interior of the foundation wall. The larger plates gives it more bearing area over concrete. Good point on the curling. Our bolt layouts are always closer together for the wind zones, 24" min. And we stagger them in the center third.
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ICF, that makes sense, only see that here in commercial. Most liability policies exclude it so it seemed to die out here quick with all the rot issues in the mid 2000's
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To me, that 2x4 looks like a creative way to improve the seal between the sill plate and concrete. You won’t find any reference to that in the building code because code is minimum standards only.
I’ve also noticed in Canada they are more worried about moisture control and less worried about engineering and structural integrity. When I’ve gone across the border I was surprised by the way they throw their sheeting on, putting it on sideways, and the lack of hold downs. Having a gap in their sheeting for vapor transfusion I think is the reason for sideways sheeting, which of course sacrifices sheer value. Also, with all the recent mold and mildew lawsuits, your architect is probably paranoid about keeping moisture out. Probably the reason for the 2x4 in the concrete. Just some speculation there.
I’ve also noticed in Canada they are more worried about moisture control and less worried about engineering and structural integrity. When I’ve gone across the border I was surprised by the way they throw their sheeting on, putting it on sideways, and the lack of hold downs. Having a gap in their sheeting for vapor transfusion I think is the reason for sideways sheeting, which of course sacrifices sheer value. Also, with all the recent mold and mildew lawsuits, your architect is probably paranoid about keeping moisture out. Probably the reason for the 2x4 in the concrete. Just some speculation there.
That detail would allow for getting the siding down further below the top of foundation wall.
Most siders only get the narrower starter strip.
I will typically use the taller heavy gauge metal starter. I would rather have sheathing on top of foundation wall in that case.
No idea otherwise for the 2 x 4.
Most siders only get the narrower starter strip.
I will typically use the taller heavy gauge metal starter. I would rather have sheathing on top of foundation wall in that case.
No idea otherwise for the 2 x 4.
I bet the archy read something like these pics and just wanted to do something different out of boredom.
I’ve seen this once before in northern California, but years ago when I was early in experiencing framing.
I get the concept, but don’t necessarily agree with it. Especially with the offset of anchor bolts like others have mentioned.
![Image]()
![Image]()
I’ve seen this once before in northern California, but years ago when I was early in experiencing framing.
I get the concept, but don’t necessarily agree with it. Especially with the offset of anchor bolts like others have mentioned.
Correct me if I'm wrong, but the articles you posted are referring to a keyway between the footing and the foundation wall to reinforce a cold poured joint, not a 2x4 at the top of the foundation wall. The 2x4 plate in the OP's drawings wouldn't help with any kind of lateral load or reducing "wall slippage" in my understanding.
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Being the detail shows OSB proud of foundation, and fastened to this 2x4, I'd lean towards it being to improve wall sheer performance, and added benefit of below top of wall siding detail.
I typically prefer OSB flush with foundation, but want siding terminating below it as well. I don't like naked OSB.
I typically prefer OSB flush with foundation, but want siding terminating below it as well. I don't like naked OSB.
Believe you’re right, but I think it’s a similar concept.
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