Will a 2x4 hold shock-loading on bolt hangers without cracking?

I'm building a home bolt-ladder for aiding / hauling / etc. practice. I want it to be a 12' bolt ladder (bolts every 2 feet) with 2 bolts at the top for an anchor. I would like to put the bolt hangers up a 12' tall 2x4, but I am unsure if the wood is strong enough to hold them in the case of shock-loading. The farthest fall I would take would be 12 feet. The bolt hangers would be connected to the 2x4 with 3/8" bolts with washers. Has anyone here had experience with this? Thanks.

(The 2x4 will be attached to the side of a house with fifteen 8" x 3/8" screws, with wood spacers between the 2x4 and the house to allow for space for the washers for the bolt hangers.)

sounds very interesting. Please let us know how your fall went....

I don't have an experience with this particular situation, however, I do have a forestry background and can tell you that the structural integrity of wood is dependent on many factors. These factors should be considered and researched before going forward with this.

A couple of things to consider:

Make sure to use a dense, hardwood such as Oak or Maple
- stay away from softwoods such as pine

Inspect the wood for signs of decay, fungus, insect damage, etc.
- All wood types suffer from these factors in some degree
- Study the cross section of the sample and look signs such as discoloration, stain, wood fiber damage, resin/pitch tubes, insect galleries, etc. (use an educational reference)

Weather
- Harsh/wet weather conditions will speed up the rate at which the cells in the wood break down and decompose
- Consider replacing the wood at least once a year or if it begins to show any sign of a loss of structural integrity.

Just some thoughts, good luck.

Jason Isherwood wrote:Make sure to use a dense, hardwood such as Oak or Maple - stay away from softwoods such as pine

I wouldn't want to try it. Regardless of whether or not the wood holds, it's gonna hurt like hell.

LCCgradechaser wrote:sounds very interesting. Please let us know how your fall went....

I'm not sure what part of the house this structure is attaching onto, but I guess you have worked that out. ?

I would suggest some metal in there. 2x4's aren't all that strong. They can be, but also you buy some cheap wood, drill a hole next to a knot and your "anchors" aren't really much of anything. Supposing you have some bomb-proof structure (again I hope you don't rip part of your house down) you are attaching it to why not use some metal straps in there. You could sandwich the wood between metal straps...at least the load would be distributed better and you wouldn't be relying on only the 2x4 with a 3/8 bolt through it.

Also you might want to get some stainless steel bolts. Some of those cheap Home Depot ones aren't very strong at all. I've broken plenty of the cheap 3/8" lags just screwing them into wood. I'd go larger than 3/8" if possible.

Hard to really comment without further information.

Bolts thru a 2x4 are going to be more bomber than a lot of placements you're actually going to be making. I couldn't begin to count the number of times on the Captain I'd liked to clipped into something that solid.

Having said that, I think I'd be more concerned about the mounting of the board than the prospect of the board failing. You'd probably be OK with either issue, but it's always the contingencies that get you. I think the bolts would probably be more bomber sunk into a 4x4 with lag bolts, but then mounting might be more difficult.

Are you going to belay with a TR through the top bolts or self belaying with a daisy? To be honest, it's pretty hard to fall off a bolt ladder so I think that risk is overstated.

I too suggest bolting through two 2x4s instead of one. I'd expect that that might even more than double the strength of your setup. 2" x 2" steel plates sound good as well... Just as a point of reference, climbing holds are bolted to t-nuts through plywood...

And to repeat, mounting of the board to the house is probably more critical. I'd hesitate using screws.

If you're going to invite a buddy to climb your wall too, it'd probably be prudent to have him sign a waiver...

a lot was said about "beefing up" the anchors set up, and I will not repeat the sound advice you've received. I would avoid the "drywall" screws type, as they are hardened and therefore brittle. as a result, they may "snap" unexpectedly. ( to sister the 2x4 together.)
lag bolts may serve you well as attachment agents to the house, but you must make sure that you are bolting to a solid framing member, preferably the corner of the house (which is much stronger ) and not in the middle of a wall.

why bolt through 2 2x4 when you can buy a 4x4 or larger

Jon Leicht wrote:why bolt through 2 2x4 when you can buy a 4x4 or larger

Find your local White Cap Supply store, and get a Unistrut catalog.
W/O going into too much detail, get a 20' stick of 1-5/8" slotted strut, you can choose from green enamel, gold anodized or galvanized.

Get 3/8" strut nuts, 3/8" strut washers, 3/8" x 1-1/2" cap bolts, some 3/8" all-thread, 3/8" nuts and washers and you should be able to figure it out from there. Do not trust anything to do with lag-bolts into wood.

Tell White Cap you want to cash sale, if they insist on an account tell them the name of one of the bigger construction co.s in your town.

go climb a tree. If it is yours, you could put some bolts up it. Don't count on hardware store lag-eyes to hold a fall though. Get at least 1/2" x 6" galvanized hardware for fall protection.

Just something to think about, but aiding bolt ladders is pretty straightforward and you won't get much out of it after a few weeks. You will probably spend more time constructing your bolt ladder than you ever will using it. Talk to your local climbing gym and see if they will let you aid their lead cave, maybe after hours when they are cleaning or setting routes.

It will be easier to use T nuts on the back side and bolt it directly to your home. A single 2x4 will be plenty strong for body weight...you don't bounce test most bolts when aiding. Just make sure the attachment to the wall is bomber...into studs not just siding.