Why does nobody talk about how critical joist depth is for deck deflection

I just redid a deck I built 4 years ago because the middle of the span had this annoying bounce when you walked across it. I used 2x8s on 16 inch centers like I always did and thought it was fine. Then my buddy who does commercial framing walked on it and said 'bro this is gonna sag in a few years.' He showed me the IRC span tables and I was like wait I've been undersizing my joists this whole time. I live in Phoenix so I guess I just never dealt with snow loads or anything but still. I feel like an idiot tearing out a perfectly good deck. Anyone else figure this out the hard way or was it just me?

2 comments

2 Comments

emma_ramirez19d ago

Oh buddy, you and me both. I built a playhouse for my grandkids four years ago and used 2x6s because that's what the lumber yard guy said was standard. After three summers of kids jumping around in there, I noticed the floor was starting to feel like a trampoline. I had to go back and sister on some 2x8s underneath, which was a real nightmare with all the insulation in the way. Now I keep a printed copy of the IRC span tables taped to my workbench like a safety blanket.

wren30119d ago

Ha, that's rough man. I mean, nothing like having to crawl under a finished playhouse to undo your own hard work, that's a special kind of DIY karma. I swear, half of my home improvement projects are just learning the hard way that the 'standard' isn't the same as the 'right' thing. At least you got a new safety blanket out of it, I guess I just have a growing collection of 'lessons learned' in the form of oddly shaped scraps of lumber.