As discussed in a previous thread, I'm reframing my porch deck and
joists. On one end of the six foot span the joists hit the sheathed
exterior wall of the house, so I'll be using a ledger and joist
hangers. On the other end there is a porch knee wall and cripple wall
below that are framed as a single stud wall. The old joists ran into
this wall and were each nailed to the face of a stud, i.e. it was
balloon framed. Is there any advantage to balloon framing like this
over using a ledger and joist hangers?
BTW, it seems like a ledger and joist hangers don't provide much
resistance against the joists pulling away from the ledger, as this
would put all nails holding the hangers to the ledger into withdrawal.
Is this a concern?
Its a good practice to use lag bolts to attach the ledger- prob. not a
risk in your case, but for folks with a porch against the house, and
just a few support posts on the far end, ledgers that are just nailed
to the house have pulled out and dumped people to the ground.
having all the joist hangers pull out of the ledger is much less
Why do you say this? Is there some reason to think that the
withdrawal strength of a nailed metal hanger/wood connection is
greater than the withdrawal strength of a nailed ledger/wood
connection, if the nail diameter and the penetration into the second
member are the same? Or do you mean to suggest that the joist hanger
solution will simply have more nails? Just curious.
I'm no expert, but I would expect the direction of the grain makes a
difference. I've always found nails easier to extract pulling in the
direction of the grain. No, I don't have a cite, just in my experience.
One thing I can say for a fact, more nails means more friction.
I like the thought about the nails being harder to pull based on
I'm guessing also that there's something like the joists can't act as a
lever against the ledger the way the ledger can against the house for
any loads parallel to the ledger.
The joist hangers I've used require two toenails on each side,
plus a few nails driven directly into the ledger. With out
the hangers, you've only got the toenails, so I 'spose it would
depend on how many you drive. The bad news is if you
support your joists with nails driven straight through
the rim-joist into the end-grain. THAT gives you no withdrawal
resistance at all.
There are (at least) 3 ways to do this.
1. Balloon framed where joists run into wall cavity and are face
nailed to studs.
2. Balloon framed where joists run into a ledger attached to the
3. Platform framed where you have two separate walls each with top and
bottom headers and a rim joist capping the joists.
Balloon framing resists in/out racking better than platform framing
because there is no hinge point. Whether this is important or not
depends on whether you have outward forces from the roof, or live in
an earthquake zone, and whether the side walls provide resistance to
racking. If you are depending on the joist/wall connection to help
resist outward forces from the roof (or eathquakes) then method 1 is
probably best. Joist hangers aren't effective at resisting outward
force (unless you use the types with flanges that can be nailed off to
the top and bottom of the ledger.
Balloon framing, in theory, allows easier snaking of utilities, but
because it also allows easy propagation of fire up the wall, you
should always install fire blocking, which negates the snaking
Method 2 allows the joist spacing/placement to be different from the
stud placement/spacing, which may be an advantage in some designs.
Balloon framing is a little easier to insulate effectively, especially
with method 2, because the insulation can be run between the ledger
and the ouside wall. This is somewhat defeated by the fire blocking.
Platform framing gives you top and bottom plates to nail baseboard
molding and drywall to.
Platform framing lets you use shorter (and cheaper) studs. It sounds
like you have short walls, but when balloon framing a tall assembly,
it can be a real challenge to find long, staight, studs.
That's all that comes to mind at the moment...
Right, because the nails from the hanger to the carrying member would
all be in withdrawal. What about replacing these nails with a
structural screw, such as a Simpson SDS screw? I wonder what sort of
outward resistance this would give.
Thanks for the extensive answer on balloon versus platform framing.
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