The Great Indoor Hang Debate

[bmorebhoy]

You've probably figured it all out by now but when I first moved into my apartment I slept in a hammock before I was able to make a bed. One wall was brick where I used a masonry drill bit and hammered in a lead sleeve to hold the heavy eyebolt. On the drywall side of the room I drilled a line of small exploratory holes to find the wooden wall stud then screwed in a screw hook.
Now I've stretched chain floor to ceiling. You still need to find the floor support beams and ceiling beams to sink your hooks into and I keep the chain loose with turnbuckles. The chain gives me varied heights to test my hang angle for comfort and I can rig up my tarp for repairs and other work.
https://www.hammockforums.net/forum/...ttan-Island-NY

[Catashep]

I cannot say I am an expert at this but I am a mechanical engineer who has done a lot of renovations and helped build 2 cottages. Given the work I do is typically for myself (not for profit obviously), I usually build things above code and consider worse case scenarios. I am in the process of planning a location to hang indoors and I will design believing multiple people may use hammock (I have 2 teenage daughters) when I am not around. Here are some tips / ideas to consider. I realize many of these have already been stated in past posts in one form or another. You should be able to do this if renting, but may require a bit of taping/mudding at end of lease....that will be a requirement with almost any indoor hang set-up without a floor frame. I apologize in advance if I am stating the obvious in any of this post.

1) Use the best hardware you can find...pay the extra $ and give yourself more safety factor. Make sure you anchor in the middle of a structural member and anchor is fully embedded in that member as this is the vendor spec for sure. It is not uncommon that a stud can be twisted thereby leaving your anchor on partially embedded. It will be difficult to determine this without removing drywall. You should feel increasing resistance while embedding an anchor. Drill pilot holes 2/3 of the depth. It's best to search web for proper pilot hole dimensions for the anchor and wood you are using.

2) Know where your electrical and plumbing is in the walls/ceiling. Both of these service run through studs/joists and it is not uncommon to puncture electrical, water supply, or drain with nails or screws and this could be a very costly error. It is especially important with hanging as the lag bolts (my recommended anchor ... with 100% thread) as you will want to embed deep into the structural member and this will increase the chance of hitting some sort of service (elect/plumb/etc);

3) I believe it is best to hang from ceiling joists, if possible. When doing so, hang parallel to the joists and place at least one of the anchors (preferably both) within a couple of feet, but not too close, to where the joist meets a vertical support (i.e., wall or beam). If hanging from a ceiling, span a minimum of 3 joists with a 2x4 and anchor in the middle and into the middle joist as well (long anchor);

4) If hanging from a 2x4 wall make sure the wall has wooden 2x4 studs...not steel. Many non load bearing walls are made with steel studs. This will save you repairing damage and finding an alternative wall to use. If you can, use two load bearing walls as this will give yourself even more safety factor. When hanging from a 2x4 wall, span a minimum of 3 studs with a 2x4 and anchor in middle of that and through into the middle stud (long anchor). Aesthetics may be a concern here. I intend to taper ends and paint them out...other people are probably much more creative than I on this so would appreciate any ideas;

5) When spanning multiple joists/studs, understand the anchors used to mount the spanning members is very important as the load is transmitted through these anchors. Again, I recommend stainless lag bolts with washers (I will be using minimum 5/16 diameter while understanding the more anchors I use the smaller they can be);

6) Torque (or moment) on your hardware or joists/studs can be your enemy and is why I suggest a few things to combat this;
- hang parallel to joists
- hang perpendicular to walls
- place hardware directly on bare stud/joist when possible (you may need to remove a small section of drywall). This one may be a bit of overkill but you need to understand that drywall can take zero lateral force essentially leaving the anchor unsupported through the width of the drywall.
- rotate your hardware to be parallel with your hang. The idea here is to eliminate torque on the hardware and allow the force to move directly into structural members
- spanning several joists/studs not only spreads the load over multiple structural members, it spreads any torque that may exist as well. This is particularily important when you are unable to hang parallel to joists/perpendicular to walls.

When I follow the above, the hammock will fail before the anchors/walls/ceilings. Let me know if you have any questions/concerns.

[thesilence]

There is a reason that wall mounted sinks and toilets are mounted on carriers and not just the studs...


Ok so a 2x4 Douglas-Fir wall stud can handle around 530 lbs in bending and Spruce-Pine-Fir is 487 lbs. These capacities are slightly reduced by the vertical loads coming from the room which introduce buckling. These capacities are much lower than the typically recommended safety factor given on this site. That being said the bolts would most likely pull out before the stud failed, but if using an aggressive, pull out resistant bolt its possible for the stud to fail first.

[Catashep]

I agree. Failure to me means any deflection that may cause drywall cracking or other damage...not just catastrophic failure. This is why I like to spread load over a few structural members and the more anchors, the less "pull-out" force on each. It's interesting to see the #s for bending resistance. Is this assuming 8' studs?

[thesilence]

I agree. Failure to me means any deflection that may cause drywall cracking or other damage...not just catastrophic failure. This is why I like to spread load over a few structural members and the more anchors, the less "pull-out" force on each. It's interesting to see the #s for bending resistance. Is this assuming 8' studs?

Yes that is for 8' studs. Longer would have a lower bending resistance, shorter a higher resistance

[Catashep]

Thanks thesilence. Are those numbers for the bending the stud on its 3.5" dimension or the 1.5"? I looked around for deflection #s and couldn't find any. Of course having a sheet of drywall well screwed across multiple studs would help too. What I am trying to get to is an estimated load that could damage drywall even though that calc can be a bit subjective. With that deflection info for both dimensions, we could assume drywall screws don't take a load and we can use trigonometry to calculate the effect of hanging on an angle to the wall rather than perpendicular as I have suggested above (which ensures the max bending strength ... along 3.5" dimension).

[thesilence]

Numbers are based off the 3.5" dimension

Deflection of a 2x4 supported on each end would be .49" for a 200# static load. For a complete wall system the deflection may be less, but do not forget that this was only for a static load with a 30 degree angle of dangle; it does not include forces introduced by getting in and out and swinging.

Drywall can handle the .49" deflection, in fact it deflects a lot more than that when it is being installed.

[Catashep]

Thanks again. These numbers are likely for load at mid-point of stud. If I assume the nails/screws at the ends take anything we could worry about, the deflection would be linear from .49" to 0. If hanging hammock at 6' above floor, I believe the deflection would be approx. .25". Your point about static load is a good one. I think we should allow a dynamic load of 2-3x that of the static. Do you agree?

[thesilence]

Thanks again. These numbers are likely for load at mid-point of stud. If I assume the nails/screws at the ends take anything we could worry about, the deflection would be linear from .49" to 0. If hanging hammock at 6' above floor, I believe the deflection would be approx. .25". Your point about static load is a good one. I think we should allow a dynamic load of 2-3x that of the static. Do you agree?

That sounds about right. All in all after running the calculations I've concluded that it should not be a problem to hang from a stud; however, personally if I ever hang indoors I will probably use something to spread the load across multiple studs just to ease my engineering mind.

[xtemplarx]

I have hung indoors, and have had a near failure. I have some big eyes in the three by ten ceiling joists. One day I noticed that the bolt was at an angle, it was pulling through the joist wood, and when I pulled on it the other way, it dropped right out. So to anybody hanging indoors from a ceiling, I would recommend hanging a pole between the two ceiling points, then the hammock from that to put the compressive forces on the pole instead of pulling on the ceiling.

I was going to suggest this. Ideally, you could extend two supports from the joists in the ceiling above you that would then hang down and support both ends of a pole (like a top-rail, as one would use in a turtledog stand). that way, all of the hammock forces are dealt with - the pole deals with the compressive (horizontal) forces easily, and then all that's transferred to the joists above are downward forces. Assuming you installed supports properly, this would be the most ideal way.