Deck railings are comprised of posts, top rails, bottom rails, spindles and cap
(usually 4x4 stock) are installed first at the corners of the deck and at intervals
no greater than about 8 feet.
can be a single post set at each corner or 2 posts on either side of the corner
with no more than 4" between them
posts are set against the rim joist, so if there's an overhang on the deck boards
they should be notched in flush with the rim joist where the posts go.
secure a post, first set it in place and plumb it in position. When it's plumb,
trace reference lines to show where the tail should end up on the rim joist and
set the post back down.
exterior construction glue over the inside surfaces of the notched area.
the post back in place, line up the tail with the reference lines and drive in
a couple of galvanized screws to hold it in place.
finish securing it by pre-drilling for 2 lag screws and driving those through
the tail into the rim joist. For a stronger connection use carriage bolts, which go all the way through the post and rim joist and are secured with washers and nuts.
The bottoms of the posts are often notched out so part of the post sits on the
the notches are cut to the height of the rim joist and to a depth of about 2",
leaving a tail 1-1/2" thick on a 4x4 post.
a circular saw to cut along the sides and then set the blade for 2" to cut across
the face of the notch.
TIP: The circular saw doesn't quite reach far enough in to finish the cut. But if
you hammer on the notch, it'll break the waste free and you can chisel away the
CAUTION: Check with your local building department about any special requirements for attaching railing posts. Some may not permit notching. Some may require the post to be screwed to more than just the rim joist.
Once the posts are all secured, you can attach the rails individually to the posts
or assemble the railing sections on the deck surface and set them in place as
between the posts to get the exact lengths of the rails, cut those and lay them
parallel on the deck.
building codes require that the spindles on a railing have no more
than a 4" gap between them. So with 2x2 spindles (which actually
measure 1-1/2" x 1-1/2") the spindles should be spaced
no more than 5-1/2" on center. It usually looks best to measure
the space between each set of posts and for each section of railing
calculate a gap between spindles (equal to or less than 4")
that will create even spacing.
cutting the spindles to length, nail or screw them into the rails at their marks
to finish each section.
a railing section is assembled, set it in place between the posts and angle screw
through the sides of the hand rail and the bottom rail into the posts to secure
it, or use galvanized connectors.
align the railings in the center of the posts, put marks at the center of the
post and at the centers of the rails. Then line those up during installation.
TIP: It's hard to hold the railing section in place while you secure it, so cut
2 blocks of wood to the exact height you've allowed between the deck and the bottom
rail (2-4"). Set the blocks next to the posts and rest the bottom rail on those
as you line up and secure the hand rail.
all the railing sections before setting the cap rails, which go over the tops of
the railings and the posts.
the cap rails by leaving equal overhangs on each side and secure them by screwing
or nailing down through them into the rails and posts.
On a stairway, you can notch the post tails to let part of the post sit on the
tread. However, this cuts into the walking area, so the posts are often secured directly
to the stringers without notches.
posts are generally secured before the tops are cut to height, so the stairway
itself can help determine the height and the angle.
determine where the top of the post should be cut, set the tongue of a framing
square (the 16" side) across the front of the treads above the post and use a
straight-edge (like a level) to transfer the angle at the top of the blade (the
24" side) to the side of the post. That represents the cutting line. Use a square
to transfer it to the other 3 sides and cut the top with a circular saw.
On stairways, it's easiest to set the rails and spindles individually rather than
the hand rail on stairways, lumberyards usually have special stock molded on one
side for gripping.
Once the rails are done, mark the spindle location on the hand rail.
get the same span on the stair rail as on the deck rail, first divide the stair
run into the rise. Multiply the result by the span used on the deck rail. Take
the square of that figure, add it to the square of the deck rail span and find
the square root of that, which will be the spacing to use in marking the stair's
hand rail. It'll be a bit longer than the span you used on the deck rail, but
since the stair rail sits at an angle you'll end up with exactly the same horizontal
spacing between the spindles as on the deck railing.
a level to plumb down to the bottom rail from each mark on the hand rail and mark
off a matching mark.
the spindles to the length needed with the appropriate angles on the ends and
attach those to the hand rail and the bottom rail.
If you've been planning a skirtboard, you can install that after the railings
Cut the boards to fit between the post tails, and nail them into the rim joist.