point of rotation on edge rail post
point of rotation on edge rail post
(OP)
ok folks,
I'm checking a platform post attachment. The steel post is attached to (2) 2x12 as shown in the section attached. (Ignore the brackets at top and bottom of the post - they're for a separate location.) I'm checking the withdrawal capacity of the 2 lag screws and am fine when the req'd 200 lbs moveable load is applied horizontally to the right. However, when the load is applied to the left, where would my rotation point be? I've talked myself into the bottom of the post (almost at the bottom of the 2x12s, the center of the two lag screws, and at the top lag screw, and can't decide which is the right one.
Where would you put the rotation point and why?
thanks,
SLTA
I'm checking a platform post attachment. The steel post is attached to (2) 2x12 as shown in the section attached. (Ignore the brackets at top and bottom of the post - they're for a separate location.) I'm checking the withdrawal capacity of the 2 lag screws and am fine when the req'd 200 lbs moveable load is applied horizontally to the right. However, when the load is applied to the left, where would my rotation point be? I've talked myself into the bottom of the post (almost at the bottom of the 2x12s, the center of the two lag screws, and at the top lag screw, and can't decide which is the right one.
Where would you put the rotation point and why?
thanks,
SLTA






RE: point of rotation on edge rail post
RE: point of rotation on edge rail post
RE: point of rotation on edge rail post
Was sitting at a traffic light tonight and a van full of "Jacksonville Roller Girls" pulled up. Thought about you.
Cheers!
RE: point of rotation on edge rail post
(Watch out for the lag bolts coming loose over time in the wood as the wood dries and the posts get vibrated. Could you use through bolts of the same diameter?)
(Also, the lower end of the 2x12 will squish a little bit - which would reduce that 2" inches to maybe 1-1/2 to 1-1/4 effective length, but as it squishes, it resists force more ... but I don't think either effect will be very much.)
RE: point of rotation on edge rail post
BA
RE: point of rotation on edge rail post
RE: point of rotation on edge rail post
If the 2x12's are in place, they would tend to rotate counterclockwise under pressure from the post. If they were fixed in place so that they could not rotate, the post would bend as a cantilever fixed at deck level. Provided the deck was capable of taking the post reaction, the lag bolts would feel no load.
BA
RE: point of rotation on edge rail post
RE: point of rotation on edge rail post
BA