Is it normal for a 15k deck to only use three posts?

Fifteen thousand dollars for a week's worth of work usually puts you in the ballpark of a mid-sized deck, but the structural details you're describing suggest they might have cut some corners on the engineering side. Three posts for a whole deck sounds pretty sparse unless the span between them is very short. If those posts are more than 8 to 10 feet apart, you're putting an enormous amount of stress on the beam and the footings.

For that price point, you should be seeing **mechanical fasteners** like through-bolts or structural screws connecting the beam to the posts. A proper notch where the beam sits on a shoulder of the post is the industry standard for distributing that weight directly down the wood grain. If the beam is just sitting on top of the posts without a notched shoulder or a heavy-duty galvanized connector, you've got a potential pivot point that coud cause issues over time, especally with a significant cantilever. The cantilever section needs to follow the rule of thumb where at least two-thirds of the joist length is supported behind the beam for every one-third hanging over. If they pushed that ratio or skipped lateral bracing—those diagonal 45-degree pieces of wood between the post and the beam—the whole structure is going to feel shaky when several people start walking around on it.

Most deck failures don't happen because the wood snaps; they happen at the connection points. You need to check if they used a **ledger board** with proper flashing and lag screws into the house rim joist. If the deck is free-standing on just those three posts, the lack of bracing is a major red flag. For 15k, you didn't necessarily get robbed on price alone if the material quality is there, but you might have gotten a crew that prioritizes speed over long-term stability. I'd look closely at those post-to-beam connections to see if they actually used hardware or if they just toe-nailed the main supports and left it at that.

Whoa, 15k is a huge chunk of change! I’m brand new to the forums and just starting to plan my first DIY deck, so I'm super pumped to see what everyone is building. Seeing those big numbers is definatly a wake-up call for my budget though! Since you mentioned they used pressure-treated lumber, did they give you any advice on when you can finally stain it? I’ve read conflicting things about needing to wait months for the chemicals to dry out before the wood can acutally take any sealer. I'm dying to know if that's actually a thing or just an old myth!

I totally agree that three posts sounds light for that price tag. One thing that hasn't been mentioned is the actual size of those posts. If they used 4x4s for an elevated deck at that height, that's a big red flag even if the spacing was okay. For 15k, you relly shoud have 6x6 posts to provide enought surface area for that beam to sit on properly. If those are 4x4s, they probly didn't have enough meat left to do a proper notch without compromising the post, wich might be why they skipped it. Check the dimensions—if it’s not a 6x6, that’s likely where they saved on material costs.

Seen this a dozen times before. These new crews love to fly thru a job, but speed don't mean squat if the thing sways like a willow in a gale. Back in my day, we’d never leave an elevated deck without some serious knee bracing—those 45-degree sticks between the post and the beam. If you don't have 'em, that 15k deck is gonna rack and ruin your siding. Give it the old 'shake test' from the corner. If it moves more than a hair, they skipped the lateral stability. For that kind of money, it shoud feel like it's part of the foundation, not a card house.

Quick update — I went back out to check those posts and they are 6x6s, wich is a relief. However, someone mentioned knee bracing, and there’s absolutely none of that installed. I noticed some swaying when I walk out onto the cantilevered part now that I’m looking for it. For 15k, shold those braces have been included, or is that usally considered an extra structural add-on?