6x6 Posts on 4x4 Anchors

I have just inspected a pergola -free standing trellis- with four 6x6 posts, 12-feet high, anchored to the patio slab by metal anchors set in concrete. Each post is secured with two half-inch through-bolts with washers. However, the metal anchors are 4x4. The builder cut a deep vertical groove (about 12-inches) up the bottom of the posts to accept the metal bracket, then sealed the cut. Is this to code? Do 6x6 posts require 6x6 anchors, or are 4x4s acceptable?

I know of no specific building code that covers trellis construction. It maybe included in general code that covers “good construction and building practice.” I would just report that you see and comment that “the strength of the column was compromised by the method of attachment”. In some municipalities permits for such structures are not required others they are. Where they are who knows what standard was acceptable except the inspector.

Wrong hdwe for the app. The post should never have been cut. Fortunately it is only a trellis and not a deck built to hold people.

Try looking at the Simpson catalog to find the correct part. But does that really matter now that it is done?

The better question is, does it really make any difference?

It took more time in labor and and filler than to buy the correct post anchor.

It’s probably all he had in the truck. :wink:

Looks more like the rebuilt something. The original 4x4 were already installed in the concrete and they built the new pergola using 6x6. Not a bad fix short of tearing up the concrete.


With the relatively light loads associated with a typical pergola, it should be fine.

Thanks for the input everyone. I should have mentioned that this was part of the original construction of this 2007 built home. What I am hearing is that it may or may not be a minor infraction, but it is free standing, not part of the structure of the house and certainly not worth the trouble of correcting. That was my initial assessment. I am 300 pounds and I pushed up against the posts fairly hard. It is a solid structure is some minor movement, but certainly not in any danger of coming down anytime soon. I guess I will mention the mis-matched hardware, but state that it does not warrant any corrective action. Thanks!