treated PSL int exterior CMU pocket 1

[SLTA]

Hi folks,

I asked in the wood forum, but it's rather slow over there, so I'm hoping for more insights here. (Yes, I've asked for that thread to be deleted, so no double-posting.)

I have a project where treated PSL beams need to be pocketed into CMU walls in an exterior application, and I can't find guidance on a detail. With steel, I'm used to requiring a grout-packed pocket with anchor bolts down into the CMU to hold the beam in place, but that doesn't make sense here. I'm also concerned about water ponding. Can I get some suggestions, or a recommended detail? I'd love to use a metal bracket but the loads are too great.

On the wood forum, msquared48 suggested "mounting the beam to an inset bearing plate with side plates in the wall, with rebar welded to the underside of the bearing plate embedded in the wall, and a 1/2" air gap between any cmu or grout" (thanks Mike!). My additional question to this is, would the rebar be set while the grout in the cores is still wet? Otherwise how would you get the grout in the cells below? Or is it an epoxy retrofit?

cheers.

 

[Michel60]

Good afternoon slta,

I don't have an answer for you but I do have a question, where are you getting treated PSL's? Last time I asked an engineered timber manufacture about treated materiel they told me they wouldn't recommend it. The only "approved" treatment at the time was solvent based and not allowed for use in the continental US. Water based pressure treatment commonly used for sawn lumber, they said, caused too much swelling when applied to engineered wood. I'd appreciate any references.


thanks,
Michel

 

[SLTA]

Michel,

I talked to the people at iLevel and they have a type of PSL they call "Parallam Plus", which is basically a pressure treatment. They publish a reduced design values brochure, which is very helpful.

See this:

http://www.woodbywy.com/exterior/e_ParallamPlusPSL.aspx

 

[Michel60]

Thank you...from the on-line description it sounds like they must treat the wood fiber before creating the timber section.

Good to know it's available.

Thanks again,
Michel

 

[dhengr]

Slta:
Why not a pocket large enough (wide enough) to accept a bearing plate with anchor bolts, grout, etc., much like your steel beam pocket detail. Standing on this bearing pl. are two side pls., spaced to fit the wood beam, and with a couple bolt holes for bolts through the end of the wood beam. You might want to consider a lintel block right over the pocket, a few blocks long. Then close the sides of the pocket with a couple thinner conc. block units. Flash this whole opening properly the keep water out, top and sides. Consider some peel-n-stick flashing material around the wooden beam end and on the top edge of the wooden beams, overhanging each side by .5", to keep water off of the tops of them.

 

[msquared48]

Sita:

I posted an answer to your question from my I phone in the other string. Yes, the rebar, as welded to the bottom of the bucket, would have to be wet set. That's the norm.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[msquared48]

slta:

Also, you could straddle two cells with the bucket with one rebar into each cell, allowing cells to be grouted from the top too.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[SLTA]

Cheers, guys. Mike, thanks. I didn't see that other post and my architect was screaming