Old House Remodeling:
Porch Floor Framing
And Joist Hangers
Bruce W. Maki,
|This is a photo from an earlier stage. Note how
the porch roof is supported by the house on two sides. The porch
post only supports one-fourth of the total roof and floor
Nevertheless, the porch roof structure is heavy and must be
supported during remodeling. We installed a pair of long
2x6's to prop up the roof. I was never very comfortable
relying on these boards, so I added a hydraulic jack for
part of the duration.
||The starting point for the porch framing is the
ledger joist, which was attached to the house with deck
|We used this hydraulic jack with a post to lift
up the porch roof slightly. We also had in place a pair of long
2x6 boards for additional support.
||We made this odd-looking U-shaped block to avoid
lifting on the fragile millwork that runs across the front edge
of the ceiling.
Let The Framing Begin:
|First we installed a 2x6 to define the edge of
the porch. We supported it temporarily with a pole and a
||We installed the 6x6 treated post that holds up
the corner of the porch deck. The white post (part of the
original porch framing) was simply dangling from above.
|We backfilled the post hole. We placed gravel
right next to the post and plain soil everywhere else.
View the article about building
the post foundations.
||We installed a pair of 4x4 treated posts to
provide extra structure for the steps and handrail.
|We completed the initial framing that defined
the outer limits of the porch. The long treated 2x6 in front is
supported in the middle of its span by those two 4x4 posts.
||The old porch column had some
minor rot problems. We filled the holes with epoxy wood
|We digressed at this point and did two little
extra jobs... we parge-coated the stone foundation wall
and we laid 8x16 concrete patio pavers (the cheapest we could
find) on the dirt under the porch.
Why did we do these minor steps?
Parge coating the wall, which involves simply troweling on a thin
coating of mortar and brushing it smooth, will help hold the stones
in place. This house uses large cut stones for the visible sections
of the foundation, but under the porches it uses plain round rocks.
Figuring nobody would care if the barely-noticeable sections of the
foundation were not original, we decided to add an extra layer of
protection against air infiltration and bug invasion.
We installed the patio paving stones to provide a reasonably
smooth floor under the porch. We laid the pavers with a 3/8" gap
between them and then dumped a bag of pre-mixed masonry mortar into
the cracks. We used a broom to spread the mortar and then wetted the
cement with a light sprinkling from a garden hose. Before we laid
the pavers we laid down a sheet of plastic to keep water away from
the foundation. (This section of foundation once leaked badly, now
it does not leak even during the worst rain storms.)
We plan to use this under-porch space as storage for outdoor
things like ladders and garden tools. Having a clean concrete floor
will help keep these things from deteriorating. Also, a seamless
concrete floor will keep weeds from germinating in the under-porch
space, and will discourage insects and rodents from living there by
creating a hostile (i.e. clean) environment for them.
||After we finished the parge coat on the
foundation we applied a bead of caulking (red arrow) between the
cement and the ledger joist. This will reduce cold-air
infiltration and eliminate many entry points for insects.
used caulking because the stone rubble foundation was very rough
and no other type of flashing would work here.
|With those minor tasks complete we resumed the
framing of the floor structure. We installed a pair of
double-2x6 beams between the house and the front of the porch.
||The other end of the beam is attached to the 4x4
post that will support the steps and handrail. Note how the 2x6
that dead-ends into the post has a metal framing bracket to
securely attach it to the post.
|The other 2x6 overlapped the post so we secured
it with 5 long deck screws. These are Deck-Mate brand 3" deck
screws, not drywall screws.
||A common problem in framing is warped lumber.
But two boards placed side-by-side can present an opportunity to
remedy the situation. Note how badly mis-aligned the boards are
(red arrow), even though they are aligned at the far end.
|Our solution was to clamp the two boards
together with Quick-Grip clamps and tap them with a hammer to
||Then we drove in some 3" deck screws to connect
the boards together.
|Afterward the same boards are aligned much
||This is a joist hanger for a double 2x6,
available at Home Depot and other stores.
Our installation procedure for joist hangers is not what
most professional carpenters do. Most carpenters install the hangers
first, aligning one edge with a vertical line on the wood and only
fastening that one side initially. Then they install the joist and
"wrap" the un-attached side of the hanger around the joist and drive
in the nails.
We don't follow that technique because the tops of the joists
never seem to line up adequately. It is difficult to get the hangers
in the exact position when there is no joist present to guide them.
|After putting the double joists in position, we
clamped the joist hanger to the joists.
Our approach only
works if the joists are cut a little bit extra long, so
they fit snugly and don't fall down.
||With the hanger clamped in place we drove in a
pair of 3" deck screws on each side. These screws go through the
joist and right into the ledger.
Note: In many cases
building inspectors require 16d nails in these
diagonal holes in joist hangers. They often won't allow deck
screws because there is a requirement that the fastener must
have the same shear strength as a 16d nail.
|Then we drove in some 1-1/4" Simpson
Strong-Drive screws, which are meant for installing these
hangers. They also sell short galvanized nails for this purpose.
Again, many building inspectors require a certain size of nails
here, such as 8d or 10d. There are short, thick joist hanger
nails made just for this purpose.
||The double-2x6-beam framing after completion.
It's important to keep this in perspective... the only reason we
made these beams was to reduce the span of the 2x6 floor
joists. The original porch on the opposite side of the house has
2x6's that span 13 feet, which is way too long.
|The beam framing from another angle. Note how we
attached the beams to handrail support posts. (These posts were
later lopped off and turned cedar newel posts were installed.)
Installing The Joists:
||We installed the joists at 12 inches on center.
This narrow spacing kept the tongue-and-groove flooring from
deflecting (bouncing) too much.
|We first installed the joists with no hangers,
because we had made them long enough to fit in place by their
||Then we installed the joist hangers as before,
by clamping them in place and securing them with screws.
|The joist framing after completion. The joists
all have a span less than five feet, which means they are far
stronger (and far more rigid) than the minimum structure that
local building codes would specify.
||A view of the connection between the
double-2x6-beam and the 4x4 post.
|The 6x6 corner post has a double-2x6-beam
connecting to it. The steel angle bracket is the heaviest
bracket we could find, it is much thicker metal than the usual
joist hangers. We also drove is some 3" deck screws on an angle
to hold the beam to the post.
||The other end of the beam shown in the previous
photo. Again, the metal bracket is heavy-duty.
The direction of the floor joists was determined by history
more than anything else. We wanted to rebuild the porch very close
to the original technique, which is why we used tongue-and-grooved
yellow pine flooring instead of the usual pressure-treated 5/4x6
Since the original flooring ran parallel to the short
dimension of this 5' x 13' porch, we had to make the joists run
parallel to the long dimension. Most people building modern
decks would do the opposite of what we did.
We also gave the floor framing a slight slope away from
the house, just less than 1/4" to the foot. Proper drainage is
important to keeping the wood dry and making it last as long as
Back To Top
- Cordless Drill/Driver
- Quick-Grip Clamps
- 2-Foot Level
- Basic Carpentry Tools
- Power Miter Saw
- Pressure-Treated 2x6
- 16d GalvanizedNails
- 3" Deck Screws
- Joist Hangers