Built up Girder

[Squirl]

I've noticed that most people use 1/2" plywood as a spacer between a triple 2 by beam over a 6x6. 
I was playing around at the store and I noticed that a 1 by board and triple 2 by boards seemed to line up with the 6x6 width.
Has anyone ever tried this?

[MountainDon]

Hmmm. The wood must be swelled with moisture or something because that doesn't add up. 

If you are placing the 2x's with the splices over supports why not forget about the long strips of plywood in the sandwich and just layer the 2x next to each other in the three layers. Then uses squares or rectangles of plywood on the outside to make up the thickness to the metal brackets? The plywood doesn't add any strength that is being counted in the IRC charts, etc. Theoretically the plywood could add some stiffness when sandwiched between 2x layers. But an engineer will not be counting that theoretical event.

[Squirl]

The 2x8s measure about 1.55 inches x 3 = 4.65 + a 1x8  is about .8 inches thick. =5.45 inches
A 6x6 is about 5.5 inches thick.  I piled them up together at the store and it fits.  I would have a solid 1x8 extra material.  I know it doesn't count towards the charts but it will add a little extra which is always nice.  And there would be no cutting of plywood.

Any reason not too?

[John Raabe]

That should work. Probably best if the 1x8 is internal to the 2xs. It won't be exactly a 6x8 but close.

[Squirl]

Just to update from the visit to the store, I grabbed a 6x6 post bracket and the 4 (3-2x8s and 1-1x8) and it fit.



I checked the label of the lumber the true width is not 1-1/2 inches it is 1-9/16 inches.  I installed it and it fit.