Hot Topics: Deck Build Second Opinion

The badly built underside of an out of code deck.

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Original Post: Need a second opinion on my new deck

dragonmom Member

Hi, I just hired a contractor to build a 16x16 pressure treated wood deck. He only put up two 6x6 posts up front and the rest is attached to the house. I know nothing about building but I don't think just two posts set up in concrete are enough to hold that side of the deck. He said he will add one more post in the middle, but I still think that's not enough. The deck is bouncing. Please look at the pictures and let me know what you think. Thanks.

Deck not up to code

Deck out of code

Highlights from the Thread

marksr Forum Topic Moderator

Welcome to the forums!

Has he pulled a permit to build the porch? I know it costs a little more, but the inspection that goes with it insures that the work is done correctly.

I'm a painter not a carpenter but agree it should have another post. Most of us prefer the posts to be setting on a footer instead of being embedded in concrete. Also the posts should have been notched so the rim joist sets on some wood instead of relying solely on nails/bolts to hold up the deck. Why didn't he continue the posts up thru the framing and incorporate it into the railing? It would be a lot stouter that way.

BridgeMan45 Member

I have to ask--did you choose the guy with the lowest estimate? I see a number of things that are totally wrong.

1. Joists not supported by adequate beam(s) for the distances spanned.
2. Joists over-spanned (too shallow for the length). They look like 2 x 8s, which have a practical maximum span of 12 to 13-feet, depending on the species of wood used.
3. Joists improperly attached at ends--appear to be end-nailed instead of held by steel joist hangers or resting on top of adequate beams.
4. As marksr mentioned, columns should be set on footings, not buried in concrete.
5. I suspect a ledger was used at the house, which is not allowed by most codes if there is a bump-out in the adjacent house wall, which yours appears to have.
6. The railing system he's building is not likely to be stout enough to resist a (code-required) 200-lb. horizontal force, although perhaps he'll fool me and come up with an adequate design.

Please tell us you didn't pay him in full yet!

chandler Forum Topic Moderator

As the others have observed, no joist hangers, too small a joist for that span. Must be 2x12, 16 inches on center to span 16 feet without post and beam.

Bridgeman touched on it, but your bump-out cannot without a doubt hold any part of this deck. No ledger can be attached to it and it must be supported from the ground.

No posts in concrete. Must be on footings at or below frost line and standing on post bases to keep them centered and off water.

Before he comes back with his hand out, here's some light reading for you to bone up on his mistakes.

hugh71158 Member

Um, I don’t know a lot about decks, but it would seem to me, with no visible bolts showing, that the post is screwed to the joist. That's not going to hold, and shouldn't the post be under the joist?

Looks really bad to me.

joecaption1 Member

All that and the rim joist should have been sitting to cut out areas on the sides of the 6x6s, not attached to the sides of them.

Decking surface needed to be at least 6 inches below and door openings. The way it is now water’s going to get in under the threshold.

Sure looks like he just used lag bolts into the end grain of the rim joist to install the railing, a big no no.

No blocking between the floor joists or where the posts are, to keep the rim from moving when someone leans on the railing.

There has to be thousands of post on DIY sites about all the damage done to homes from not building the deck lower than the door openings. I know that one mistake has made me thousands of dollars over the years.

If he did all that wrong I wonder how he attached, flashed and water proofed the wall where the ledger is.

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