Building Deck Stairs
Building Deck Stairs
Building deck stairs is actually quite easy but is probably the hardest to master as a beginner till you gain a good understanding of the process.
Components To Typical Stairs
Stringers, Tread and Risers
- Stringers cut from 2 x 12s are the sloped boards on the sides that support all the stair components as well as carry the weight of people walking up and down the stairs. Typically stringers are set on 16″ centers for strength.
When building stairs remember wider is always better for safety and comfort when using.
- A good width for stairs is 48″.
- Treads:- are the top surface of a step that you step on.
- Risers:- are the back part of the step which is installed under the lip of the tread. You can have open or closed risers but closed type is the better as they protect the end grain of the stringer from weather eliminating cracks and splitting.
Rise And Tread Calculations
- Measure the height of deck to the landing below.
- Lets say the measurement is 60″
- Next find the rise of each step (typical rise is 7″) divide 60″ x 7 = 8.57″ round off to 9 steps.
- Divide 60″ x 9 = 6.6″ per rise.
- You can now calculate the total run of the steps (average run is 10″ for comfort) as you multiply 9 steps by 10″ giving you total run of 90″
Cutting The Stringers
Decide where the stringers will be attached to the deck either to the rim joist or below using the deck its self as the 1st step.
- Make tread notches using a framing square and stair gauges. (these are little brass stop block that clamp to the square and provide consistent accuracy in the layout)
- Attach one gauge to the tongue of the square at the exact rise height. Attach a second gauge to the body of the square at the run dimension. Lay square on 2×12 with the gauges pressed tight to the edge and mark tread and run on the board.
- Slide the square down to the previous marking and add the next one.
Cutting Out The Notches
- Cut out the notches using a circular saw making sure you do not cut past the marks. Finish the cuts with a jig saw.
- Next trim the bottom stringer equal to the thickness of the stair tread being used.
- Attach stringer to deck rim joist with screws 16″ on center.
- With stringers in place, check each step for level and use block plain to remove high spots.
Installing The Tread And Risers
- Cut risers to width and attach to stringers with 2 1/2 deck screws.
- Cut the tread from 2 x 12 giving about 1 1/4 hang over to give a better look.
- Now attach tread leaving about 1/4 between boards for drainage.
Depending on the length of your stringers, you may want to screw 4×4 upright to the stringers for support.