I really can't see what the problem is, other than aesthetics. Even with
the notch as described, and the upright fastened (either lag bolted or
screwed) to the rim joist, you still have a full 2" thick post supporting
your railing. This is even if the 4X4 splits. I am not certain how much
force would be required to cause a 2" thick post to fail across the grain
but I suspect it would be more than mere leaning against the railing or
post.

This is just my opinion and I will admit I am not an engineer, archetecht or
other professional. I have, however, had a decl woth a railing as described
for almost 30 years with no problems or other failure.

I will also admit that it would be preferable to mount full 4X4s to the
inside of the deck structure and notch the deck boards around them.

"J." wrote in message
...
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?