Half wall used as guardrail
Half wall used as guardrail
(OP)
I am trying to figure out how to attach a 42" pony wall around the edge of an elevated floor and connect it to the floor in a way that it meets the 200 lb point load requirement in the IBC on guardrails. If I use 200 lb applied at 42" height, I get a moment at the base of 8400 in-lb. Using a 2x4 wall, if I try to just lag this wall down, I can't get the numbers to work at for any reasonable connection. Even assuming a put a strap or L-bracket on the outside faces of the wall, that only gives me 3.5" of moment arm for resisting the overturning, which means the restraint will have to be 2400 lb. How do these get built? Does anyone have any suggestions?





RE: Half wall used as guardrail
That might help you get a connection that is workable.
RE: Half wall used as guardrail
1. Can you balloon frame this section?
2. Here is an article for a deck handrail detail, which obviously isn't quite the same, but maybe you can modify the detail and get something similar. http://www.structuremag.org/article.aspx?articleid...
3. Can you design the top plate to span between supports at the ends and forget about bringing the load down to the base via the studs?
M.S. Structural Engineering
Licensed Structural Engineer and Licensed Professional Engineer (Illinois)
RE: Half wall used as guardrail
Unless someone else knows something?
RE: Half wall used as guardrail
Remember that the 200lbs concentrated, or the 50lbs/ft. can act in either direction on the top of the wall. The top plate on that wall has to be connected in such a way that it will distribute these loads to 3 or 4 studs. I don’t know if you can stretch that as far as 84" though. That is obviously a nasty condition, and you must be able to get down into the floor framing to make some moment connection.
Why not treat the 42" high wall like a shear wall, torsion box, box beam, whatever; with plywood glued and nailed both sides. The exterior skin laps down over the full height of the rim joist, but the rim joist needs special connection attention too. The inner skin stops at the floor sheathing, but is nailed to the top and bot. plates, which might be 2-2x’s or 4x’s. Then, every 32" or 48" (fl. jst. spacing) use a double 2x stud spaced to allow a post tensioning rod btwn. these studs. This rod gets attached to the fl. jst. with some hardware similar to that shown in the mag. article for handrail posts, but in this case in a vert. orientation. This starts to provide the moment connection btwn. the wall box beam and the fl. framing system. I would consider an outward failure as the critical condition, so place the rod off center toward the inside of the wall. The outer skin acts as the tension tie on an inward failure. Don’t over tighten the post tensioning rods, they will just tend to loosen due to creep and shrinkage in the wood framing, but they are there to counteract any tension forces when loads are applied at the top of the wall. Maybe use the hardware on the fl. jst. and on the double stud, only a foot above the bot. pl. to minimize creep and shrinkage effects. There are also spring loaded take-up devices to account for this shrinkage.
RE: Half wall used as guardrail
RE: Half wall used as guardrail
See Figures 24, 25 and 26 ??
Simpson makes connectors:
http://www.strongtie.com/ftp/fliers/DIY-DECKPATIO0...
Although I do like Dhengr's suggestion.
EIT
www.HowToEngineer.com
RE: Half wall used as guardrail
EIT
www.HowToEngineer.com
RE: Half wall used as guardrail