Do you need a PT sill if you use a sill seal product?

[BubbaJ]

Code indicates that wood in "direct contact" with concrete "shall be of a naturally durable wood or preservative-treated wood..."

If a sill seal product was used, the sill is technically not in direct contact with the concrete.

Is the sill seal adequate protection in the eyes of the Code?

We have a tall wall framed with 9.5" LVLs with an LVL sill plate. I am not aware of the option for a PT LVL sill plate.

 

[KootK]

It is my understanding that a gasket is a code compliant solution.

 

[dik]

penny wise and pound foolish?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[JoelTXCive]

Could you use a conventional pressure treated 2x10 sill plate?

The 9.5" studs would overhang the sill plate by a 1/4" of an inch.

Or, you could do a 2x12 sill plate and rip down the boards to 9 1/2" inches.

 

[STrctPono]

So is a layer of asphalt roofing felt

 

[phamENG]

I'm guessing the LVL sill/sole plate is being driven by inadequate crushing strength of PT lumber. Keep in mind if you rip a PT 2x12, you need to go back and paint the whole cut length with remedial treatment chemicals.

But yes, if you have a waterproof gasket below it then you would not have to worry about moisture wicking - just make sure your architect's exterior detailing is good and keep grade well below any exposed wood products. You'll need to do some research on the proper product, though - most of those are for sealing air gaps and not meant to protect the wood from wicking. You'll need to make sure you find a material that promises to do both.

 

[XR250]

PT LVL's are available in my area (central NC, USA)

 

[phamENG]

Really? I'd heard of them on the west coast, but haven't seen any out this way. What manufacturer?

 

[BubbaJ]

If I had my choice, I'd do both. I specified PT. I was not hired to do construction observation. PT was not used at the LVL wall, but a sill seal was used. The inspector noticed. The wall is 33 ft tall at the gable so they are not so keen on rebuilding/replacing the sill plate.

 

[XR250]

Really? I'd heard of them on the west coast, but haven't seen any out this way. What manufacturer?

Not sure but my local lumber supplier gets them easily. They work nicely on decks with minimal posts

 

[phamENG]

BubbaJ - I'd request the specs on the sill seal they used and make sure it'll do the job. If not, well, that kinda sucks for the contractor. There are ways of replacing it without rebuilding - they can run another LVL inside and out and fastened to each stud, then jack it up 1/8" and hold it place while the non-treated plate is removed and a new one is put in place. You may need to redesign the anchorage as any existing bolts would likely need to be cut off to facilitate the work.

XR250 - Kempsville Building Materials is our big local supplier, and I know they've started moving out toward Raleigh. Maybe one of their purchasing guys will have heard something about it. I'll have to look into it. Everyone around here wants to use them in large porches, and it's a hard sell to prevent it when "everyone else" is doing it. That would be a nice solution.