In addition to the insuranceman's lawyer your locality's building code
may or may not have something to say about the railing's construction.

On my back porch there are notched 4x4 posts as you've described.
However, the "tails" are on the *inside* of the rim joist, not the
outside. That way, when leaning against the rail the 2" thick portion of
the cutout bears the weight - and it's resting on the rim joist. The
tail, being screwed to the inside of the rim joist, holds it all in
place. (I'd check if they're just screws or lag bolts but it's raining
just now....)

This is a much better and safer arrangement than putting the tails on
the outside of the rim joist. Eventually that will cause the splitting
you're concerned about.

J.


Larry Blanchard wrote:
After 19 years in our home, the insurance company has decided we need a
railing on our front porch. Nobody had ever fallen off, but I guess they're
getting a little more picky after the recent disasters they've been paying
for - or paying the lawyers to avoid paying for :-).


Anyway, I'm going to make the posts from 4x4s, notched to fit over the edge of
the porch. Two inches thickness on the porch leaving 1.5" thickness for
attaching to the joists.

The notched joists are common in our area and look a lot better than a full
4x4 on the edge. But it seems to me that leaning on the rail with sufficient
weight would tend to start a split at the end of the notch. I'm thinking of
running a 3" screw or lag bolt into the post, or maybe a through bolt, just
above the notch to guard against this. Will this work as I think it will?