I feel this so much. Every time I try to figure out load distribution, I end up second-guessing myself and picturing the whole deck collapsing at Thanksgiving dinner. Is there some trick to trusting the numbers, or do you just get used to living with a little anxiety? Also, does anyone else have a hard time figuring out when you’ve crossed from “safe” to “paranoid overbuilder”? Sometimes I’m not sure if I’m being cautious or just making the lumber store rich...
“Sometimes I’m not sure if I’m being cautious or just making the lumber store rich...”
That line cracked me up because I’ve definitely been there. My last deck project, I spent half the time recalculating joist spans and the other half convincing myself I didn’t need to double every single beam. At some point, you just have to trust the math (and maybe double-check with a span table). I figure if my deck survives my brother-in-law’s “enthusiastic” dance moves, it’s probably safe enough.
“At some point, you just have to trust the math (and maybe double-check with a span table).”
I hear you on that. When I built my shed, I kept second-guessing the floor joists—measuring, re-measuring, then adding another 2x8 “just in case.” My neighbor laughed and said it could probably hold a car. I guess it’s better to overbuild than underbuild, but yeah, the lumber bill stings. Sometimes I wonder if I’m building a shed or a bunker...
I get it—when I was fixing up my old porch, I kept thinking, “Did folks in 1905 really trust these skinny beams?” Ended up doubling a few, just for peace of mind. Sometimes the old ways hold up, but I still sleep better knowing it’s solid.
“Did folks in 1905 really trust these skinny beams?”
That line made me laugh—I've had the same thought staring at some of the original framing in old houses. It's wild how much faith they put in those little sticks, especially when you see how much weight they're actually carrying. I get why you doubled up. Sometimes you just want to know for sure that it's not going anywhere.
When it comes to load distribution, here's how I usually break it down for myself, especially on older structures:
1. Figure out what’s actually holding up what. Sometimes it looks like a beam is doing all the work, but it’s really just decorative or only carrying a small part of the load. I’ve pulled down “support” posts that were basically floating.
2. Check the span tables for modern lumber, but remember old wood can be denser and stronger—or, sometimes, way more brittle. If you’re not sure, err on the side of overbuilding. I’d rather have a beefy beam than a bouncy floor.
3. Look at how the load transfers down to the foundation. It’s easy to focus on the beams and joists, but if the posts or footings are sketchy, you’re just moving the problem lower.
4. Don’t forget about lateral loads. Wind, people leaning on railings, even snow drifting against a porch can push things sideways. I’ve seen old porches slowly tilt over decades because nobody thought about bracing.
I do think some of the old ways hold up, but codes have changed for a reason. People are heavier, furniture is bigger, and we expect more out of our spaces now. I’ve found that doubling up beams or adding extra blocking is rarely a waste of time, even if it feels like overkill.
One thing I learned the hard way: don’t trust what you can’t see. I once opened up a wall and found a “header” that was just two 1x6s nailed together. That was a fun surprise...
Anyway, if you’re ever unsure, I say go with your gut and make it stronger. Peace of mind is worth a few extra bucks in lumber.
