Building a set of wood
stairs is not nearly as hard as you may think. With
some basic wood tools and a bit of algebra you can
easily build your own. Of course this can get a bit
tricky for stairs with several landings but the method
is still the same.
This article will cover the steps for building a
straight set of stairs. Chances are if you are reading
this then you are still learning and won't be taking
on a complex stair anyway.
Now, we will assume that it is from a deck to a
concrete pad. The deck is going to be 48" wide
and at eye level from the ground.
Tools you will need:
- Circular saw
- Framing square
- Hand saw
- Carpenters pencil
- Measuring tape
- 4' Level
- Masking tape
You will also need:
- 3 @ 10' / 2" x 12" boards - Choose
the best only, make sure they are straight with
no check (cracks). Very Important!
- 2 @ 8' / 2" x 4" boards
- 8 @ 8' / 2" x 6" boards - Once again
choose the good ones. These are going to be the
- 1 @ 45" / 2" x 6" boards
- 1 sheet of plywood @ 1/2" / 8" x 48"
- Of course, 3-1/2" framing nails and deck
screws or nails for the steps.
Find the overall rise
We want to know the exact vertical distance from
the top of the concrete pad to the top of the deck.
Take one of the 8' 2x4's and rest one end on the
deck and hold the other over the pad, Place the level
on the 2x4 and level the board. Then simply measure
from the bottom of the 2x4 to the pad. Lets say it
is 64". This is the overall rise.
Now determine the overall run
Before we can do this we have to determine how many
steps we need.
Take the overall rise, 64", and divide it
by 7.25", which is the typical height of 1
riser (step). This gives us 8.83, which rounds
up to 9, So we will go with 9 risers.
Important: There is always 1
less tread then risers. Whether you go up or down
the last step is onto the deck or the pad. So 1
Now we take 10.5", the width of a typical
step, and multiply it by 8. This gives us 84".
This is the overall run.
While we are doing the math we need to figure
out the exact rise of each step. We simply take
the overall rise of 64" and divide it by 9
and we get 7.111" or 7-1/8", or close
enough to it. So each riser will be 7-1/8".
Time for some layout
First thing. Grab your framing square. The long
leg is the tread (step) leg and the short leg is
the riser leg. Also, use the numbers on the outside
of the square only.
Take some masking tape and wrap a piece around the
framing square to establish you rise and run. Mark
10.5" on the outside of the long leg and 7-1/8" on
the outside of the short leg.
Layout one of the 2x12's on your saw
horses or work bench. WIth the long leg of your framing
square towards the end of the board start to line
up the tape marks to the edge of the board facing
you. Once you have the square in position mark the
outside edge of it with your pencil. See picture
for general layout.
Continue to do this until you have
the required number of steps, 8 in this case. This
is always shorter by the thickness of the steps,
for us that is 1.5". This makes the first riser
Cut 'em out
Now use you circular saw to cut out the stringers
(technical name for 2x12 with stair marks on it)
being sure to cut on the waste side of the line.
When you cut into the corner with a circular saw
the blade misses some of the wood on the bottom side
of the board. This is fine, simply cut up to the
line and stop, then finish the cut with your hand
Now use the first stringer as a template for the
other two. Lay the stringer onto the 2x12's and trace
around it. Then cut out the other stringers the same
as the first.
Reinforce the stringers
Align one of the 8' 2x4's along the bottom edge
of the string and mark it to fit the profile of the
ends of the stringers. Cut the 2x4 and secure it
to the bottom edge of the stringer. Repeat this for
one other stringer. These help to strengthen the
stringers and reduce "bounce" in the stairs.
Use the framing nails to secure them.
Assemble the stairs
The plywood is used to attach the stairs to the
deck. Secure the sheet of plywood to the top end
of the stringers. The two outside stringers are nailed
flush with the edge of the plywood while the third
stringer is centered on the sheet. Simply nail through
the plywood into the face of the stringers using
framing nails. 4 into each stringer will be enough.
Now take the 45" 2x6 and nail
it in between the bottom of the outside stringers.
The 2x6 will fit into the notch cut into the center
stringer. This provides the right spacing for the
bottom of the stairs and secures them to the pad.
Attach them to the deck
Move the stairs into their final position. make
sure they are level across the stringers and that
the risers are plumb. When the stairs are positioned
correctly nail through the plywood into the side
of the deck. Use some 3" concrete nails to secure
the 2x6 spacer to the concrete pad.
Install the treads
Cut the 8 - 8' 2x6's in half, be sure to cut them
square. Starting at the bottom of the stairs, start
placing the 2x6 stair treads. Simply center them
on the stringers and use some 3"deck nails to
attach them. You can also use an exterior adhesive
to assure that they don't move.
Continue to work your way up the stairs until you
reach the top.
You are done... well, almost
Railings. You need to install a railing to keep
people from falling off.