help with pergola construction (long)

[Jason Morgan]

I am building a pergola for my deck and I have a question Im hoping someone can help me with.

My question is about the grid work that makes up the "roof" structure (open lattice structure providing all the shade). My plan is to have a grid of 2x6s on 18" centers with members running east-west and cross members running north south, and i was wondering how to construct the grid (how do all you pros do it anyway). I have thought of two ways to do it.

First is to notch the top of east-west and the bottom of the north-south members of the grid half way through their depth so that they fit into each other (kind of like a tall skinny half lap joint). This seems like a lot of work and I am sure would be strong, but Im thinking it may be hard to make it look good.

The second way is to leave the east-west beams whole and cut a bunch of 16.5" lengths to make the north south members out of. This sounds much easier, but I cant think of a good way to attach all of them. I really dont want to stagger them. (how to I attach both ends?) I guess I could attach one end normally and then toe nail in the other end from the top and bottom of the east -west member. This doesnt sound early as stron, but this structure only supports itsef, no load.

How do you pros to it (#1, #2, or something completely different??).

I've looked at all of the work that Kelly Hanna has posted, but cant really tell how he does it.

Hope this isnt too confusing.

Thanks in advance!

[Frank Chaffee]

Jason,
Either notching or blocking will work.

My concern would be the regular egg crate series of squares, which reminds me of the ceiling in my dentist’s office.

If notching, I would notch ½ way thru the top members only, so as not to expose a cut on the lower members to water. This also offsets the plane of the two layers.

If blocking, I would use one row of 2x6, two rows of 2x4’s, then another row of 2x6, etc. 2x4 rows flush to top edge of 2x6’s. …Or any other pattern that you find pleasing.

Have fun,
Frank

[Danny Buie]

The final grid is woven from strips sawn from cedar fence boards. This is for the vine to grow on. Below that are 2X2's, 2X6's, 2X10's and the lowest are 2X6's. This one is 12' X 16' at the very top.