Sandwich a beam

[Eddie_T]

It's unlike you folks to give all this advice regarding an unknown situation?

 

[billshack]

Would it better to screw or nail it????
What kind of glue would be the best????
The pole is just in the way.
Only reason it's there is because of the sag.
But it just has to go.

I would get a jiffy pole and jack it up . also remove any weight on top if possible. the then jack it up as straight as possible. the glue and screw with 3/4 inch plywood and 1 1/2 inch screws with PLR
LePage PL Premium Polyurethane Construction Adhesive, Interior/Exterior, Waterproof, 295 ml
and then let it sit for a weekend, the slowly remove the jiffy pole . it it stayed true then fine in not then repeat with a second layer on top of the first . this time with 3 inch screws.

 

[abunaitoo]

So project has started.
I am sanding the paint off both sides.
Plan on using Loctite PL3X.
3/4" CDX on he inside, and ACX on the out side.
Nail gun nails.
One question......
On the joints between the ply, would is be stronger if it were cut at an angle instead of 90'????
I would think more surface area at the joint would make it stronger.

 

[tomtheelder2020]

The vertical stress on the beam will try to separate the joint at the bottom and compress it at the top. I expect the difference between vertical and diagonal butt joints to be infinitesimal but stronger for the vertical joint because the plywood would have to compress for the beam to bend (the diagonal end pieces would tend to slide past each other. Something like box joint would be stronger of course but if you need that extra strength I suspect your beam will sag too much anyway.

 

[abunaitoo]

Now that makes sense.
Thank you