Framing
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STEP FOUR: FRAME
By now you have your size figured out, and your footings installed. Typical deck framing
requires a single board against the house, and a double box ( 2 pieces on each side and 2
on the outside ). Usually there is a 1" overhang of the decking. I'll try to make
this as generic as possible so you can modify your measurements to your deck size.
The first piece is the one against the house. If I want a 1" overhang and a double
box, then my header is going to be 8" smaller than my finished deck size ( a 10' deck
would have a finished frame of 9' 10", if you make the frame 10' then you would
have to buy 12' decking to get an overhang ). We are going to build a 12' x 10' deck but I
will explain all the cuts so you can modify them.
For a 12' deck my first piece is 136", make a plumb mark 4" away from your
starting point. Now make a level line for the header and install it. Remember the header
has to be secured to the house. If
you are going under a door, leave approx. 7" - 8" from the top of the frame to
the threshold.
The next two pieces are the sides of the box. The cuts are 9' 8" ( or 4' less than
the finished deck ), butt these pieces against the house and the header, and nail. Put a
level on top of the lumber and install a temporary support with a couple of nails into the
outside of that piece at level. Do the same to the other side. Now measure (along
the house ) from outside to outside. This is the measurement for the last piece to tie
together the box. Normally I could tell you want the length is, which should be 139",
but if you are using PT lumber, often the wood is 1 5/8" or even 1 3/4" thick.
Anyway, this is the foolproof method, whatever you have against the house is your cut for
the outside. This piece is going to cover the cuts for the side pieces. Once you've
installed the outside put ion a couple more temporary supports. Making sure to check all
sides for level.
At this point we have a box attached to the house and level. Now we are going to install
the joists. Don't jump the gun and install the second box around the existing, we need to
thru-nail the joists ( nail through the outside header into the end grain of the joist ).
Measure inside to inside on each edge( coming away from the house ) the two measurements
should be identical. If there off by a 1/4" don't worry, if it's more like 3/4 or
1" then one one the cuts is wrong.
Layout the joists by measuring from one end ( on the outside, along the house ) and mark
15 1/4" . Put an "x" on the side going away from that mark. Now put a nail
in the first mark and hook on your tape measure. Mark off every 16" (usually
every 16" is in red on the tape ) and put an "x" to the same side as the
first. Use a square to mark the line the full depth of the lumber. Count how many
marks you've made and cut that many joists. While your cutting, have a friend mark
the outside header the same way. Make sure you are measuring from the same side and the
X's go in the same direction.
Install the joists over the X's and on the line. Toe nailing the inside header and
thru-nailing the outside. Making sure that the tops are flush to each other. You've
probably seen the technique of installing the joist hangers first then the joists.
DON"T DO IT. All PT lumber varies, save the hangers for the end. Believe me it will
be better.
Now you can install the joist hanger's. Typically anything that is through nailed does not
need a hanger but the toe-nailed side does ( check with you local building code).
Time to double up the box.
Measure one side from the house to the outside. Cut and install that side and do the same
to the other. Now measure the width of the outside header to cap the pieces you just
installed. Cut and install that piece, nailing the ends and every 2' or so.
Using a piece of scrap lumber, square the corners., and
your frame is finished !!!