I began installation on a heavy duty porch swing this morning (the kind usually hung from 4x4 stand-alone A-frames), and found no cross beam in the area where the eye bolts needed to be. I installed a 2x4 cross beam, but have concerns over its ability to hold the weight of the swing & two people simultaneously.
Here are the existing cross beams, standard 2x4 toed in with galvanized nails:
Here’s what I installed to hold the swing; 2x4 cross beam suspended by steel hangers, eye bolt drilled through & secured with washers & nut:
The eye bolts are ~7" from the end of the beam, so most of the weightbearing is done near the hangers, but I’m concerned that a 2x4 may be too small to support the weight. Any ideas on how to reinforce the beam, or if it’s even necessary? I had considered running the long 2x4 (seen in photo #2) across the center of the beams, perpendicular, and popping in a few lag screws in to reinforce the center of the crossbeam, but I don’t think that would do much to reinforce the high stress areas.
The first hanger is secured through the top with 3" 10d nails, then again through the face. The other end hanger doesn’t hang over the top of the anchor 2x8, but is nailed in 6 different spots. The cross beam 2x4 is secured to the hangers & anchor beams with 2 10d nails apeice, one through each side. The bottom edge of the hanger protrudes roughly 1-1/2", so I’m not really concerned about that point, so much as I am the area where the eye bolts go through. I drilled dead center through the beam with 1/4 bit, then screwed them through, but I wonder if the weight of two people plus the swing may split the sides of the 2x4 in the area of the bolt.
At the bare minimum you should block the 2x4 against the 2x4’s on either side, and especially at the ends. The combo of the weight of the swing + the movement will likely result in torquing of the sole 2x4, especially at the hangers. The most likely outcome will be that the hanger nails will eventually loosen & it will come down, in time. If you block the 2x4 every 16", staggered, and especially at each end, you’ll eliminate most of the torquing.
Of course it may just come down b/c you drilled a hole thru the 2x4, substantially weakening it. I would consider taking 2 more 2x4, and laying them flat across both your 2x4 & the existing cross beams, then drilling holes so that the weight of the swing is also born by the supporting cross-cross beams (your existing bolts look long enough to go thru another 2").
Like this, with the middle cross beam being your swing holding 2x4:
I would concerned about the twisting action on the 2 x 4 more than actually having the board itself fail.
If I can express my self properly here, every time you swing all the weight will be pulling on the eye bolt hanging down below the board. The “Vector” of that pull will change from directly below to one side, then the other, creating a torsional force.
If go look at a swing set you can see this happening as the top bar bows in the direction of the person on the swing.
I would be concerned about the effect over time and having those hangers fail as they are not really designed to take an “Offset” load like that and likely aren’t designed to take much if any dynamic loads.
You might be able to eliminate twist by running a couple cross beams between your “Swing beam” and the existing beams.
That way any “twist” won’t go into bracket but will be transferred over to the other beams.
I’d also look into weight loads of the 2 x 4 itself. If it were me…I’m not trusting a 2 x 4 in that application without knowing what the loads are supposed to be. My guess would be you’re fine, but when in doubt make it stout
I can’t tell how much room you have at the ‘shallow’ end near the roof line, but you might consider laying/securing a 4X4 on top of the framing - and longer bolts thru the 2X4 and also the 4X4 - - - then the existing 2X4 goes back to simply holding the ceiling panels.
Forget about reinforcing the beam and install a web cam. Porch swings are a never ending source of material for America’s Funniest Home Videos, right behind trampolines and weddings.
I was thinking similar hangers with double 2 x 6’s and cross beams to the other 2 x 4’s…and nothing but sleeping like a baby for me knowing that the chains will break before the boards will
One more thing I’d check is to see if the header board near the house is properly anchored to the house. Might not be if it’s only original purpose was to hold up that sheeting.
After you double up the 2x4s, think about using a hanger like this. It uses 2 bolts instead of one plus has a bushing so its less likely to wear through and break after a few years like the one you have on there now will. You can get them at Home Depot. Also, I put porch swing springs on my chains which seem like they reduce the shock on the mount when people plop down on the swing. You can get them at Home Depot too.
Here’s the final earthquake-proof configuration: blocks on each side of the eye bolts with cross beam 2x4s on top for added stability. I used shims between the ends of the top 2x4 and the boards it rests on, and torqued down on the bolt a bit to make sure they’re actually bearing some weight rather than only engaging if the main support beam gives way.
I’ll be adding springs between the eye and the chain for added shock absorption.
The cross beams have eliminated the torsional effect and you’ve effectively taken “Some”, probably not much as the way you have the top 2 x 4 mounted it will flex alot, but some none the less, to the two adjacent beams.
In any case you’ve gone to something that if it does fail probably wont fail all at once catastrophically unless SERIOUSLY over loaded.
So while the beam or hanger might give way, the top cross beam might keep everyone from plummeting to the floor
Having been a destructive child and having one that is cut from similar cloth I tend to never underestimate dynamic forces and the damage they can cause where bodies are concerned
I think you need to install cross beams to provide an extra support. Use of aluminium cross beams or wooden cross beams are best for this purpose . Your approach was also good but you need just to add support with cross beams. However current design was also good and attractive !!!
