I'm building a wall-mounted pergola. It will look something like below.

As you can see, the two horizontal 2x4s will be attached to the 4x4 bases. I was considering using these types of angles (one on each side of the 4x4 - they don't have the Simpson) to hold the 2x4. But I can also use regular wood screws.

What would you recommend?

The weight of the four 2x4s will be divided between the concrete structure (the gray) and the two horizontal 2x4s attached to the 4x4.

enter image description here

  • None of the above. SS lags or bolts, and washers for cedar; galvanized for treated.
    – Mazura
    May 28, 2021 at 22:58
  • Notch the 4x4s to keep the 2x4s from sliding down and putting sheer stress on the screws. May 29, 2021 at 0:32
  • 2
    it is a pergola, there is virtually no load from the 2x4s that are sitting on the members attached to the posts, pretty much anything would work. You aren't planning on sitting up there are you? if you can get the color correct i'd get acq deck screws 3" would be fine. galv is no good for acq pt wood. i wouldn't bother with stainless. May 29, 2021 at 2:49
  • Even for something like a pergola (as opposed to a deck), I would use some type of galvanized, or SS structural fastener. You want a fastener that has some sort of pull out or sheer force number stamped on the box.
    – SteveSh
    May 29, 2021 at 11:49

4 Answers 4


I would put cup head bolts all the way through with washers and nuts on the back. 1/4" is plenty fat enough. Four bolts per post.


I would use stainless deck screws. Drill clearance holes all the way through the 2 X 4 , and put pilot holes in the 4 X 4. The SS deck screws can't take a lot of torque and heads will twist off without the holes. Or just galvanized lag screws ( around 1/4 by 4" ). I had SS deck screws on my mind as I have been using them to replace rusted deck screws in my deck.


In addition to the earlier options, you can use these GRK fasteners. They are rated/tested for torque and moment (listed on package and website), and do not require pre-drilling.

They replace bolts of 1/4in (or so, check the specs).

You can drive them through the 2x4 into the 4x4 from both sides. Available in a variety of lengths, at least 3in to 6in.

Use at least 2, diagonally opposed, from each side. They are suitable for outdoors.

enter image description here


I would use galvanized carriage bolts. Easy to tighten up later as the lumber dries out and shrinks.

  • This pretty much seems to be a duplicate of a previous answer.
    – JACK
    May 30, 2021 at 14:54

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