# Is a 2x4 strong enough to hold up a porch swing?

I'm hanging a porch swing, but the beams run the wrong direction for the support hooks. I've looked up in the attic, and there's a 2x4, lying flat, that runs the correct direction. Will that be strong enough to support, say, 500 lbs? Due to the angle of my roof, I can't actually reach the board so there's no hope of supporting it from above.

There's really nothing stopping me from getting a different style of support hook (one that drills into the wood at a single spot instead of two), but if possible, I'd like to use what I've got.

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The more I think about it, the less likely I am going to be able to use those hooks. I guess I'm just looking for confirmation. :/ – moswald Jul 25 '10 at 18:05
I'm a bit confused about how the beams could run in the wrong direction. Perhaps I'm being dense, but if they were parallel to the swing, you could drive the hooks into two spot on the same beam; if the beams were perpendicular you could drive into two boards. What am I missing? – Rod Fitzsimmons Frey Jul 25 '10 at 18:35
As the 2x4 is flat, it's not going to be particulary strong. You also didn't mention how long the 2x4 is, as a short run is going to have less moment on it than a long run. (assuming that only the ends are well supported) – Joe Jul 25 '10 at 20:08
Get me some dimensions/schematic and I'll calculate the max stress on the 2x4 for ya. Us engineers are useful sometimes. :) – Doresoom Jul 25 '10 at 22:02
@Rod: I've only got a pair of hooks, the chains on one side both attach to the hook on that side. The problem is (with the particular hook I had) is that the hook has a very wide base that can only be attached perpendicular to the direction of swing, and since the beams run parallel, I ended up needing something different. – moswald Jul 26 '10 at 2:04

There are several issues to consider - whether the 2x4 itself is strong enough to bear the load you're putting on it in the direction that you're loading it (so the grade/type of wood is important, not all 2x4's are created equal), whether the fastener/hook you use will overstress the wood in the 2x4 at the point where it attaches, and whether the load on the 2x4 will overstress/exceed the capacity of whatever it is that's attaching the 2x4 to whatever it is that it's attached to/supported by.

My unscientific, short answer is "no", I wouldn't depend on a 2x4 of unknown provenance to support the weight of 2 adults (or any number of children) + the weight of the swing, especially given wear & degradation over time.

If it was a short run of 2x4 and the swing was attached really well and the 2x4 is attached really well to something strong, yeah, it'll probably work, but if it were my house/family involved, I'd look for a stronger way to hang the swing.

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