How To: Build a Deck Staircase
The first step is to gather the proper materials. I will assume you have the proper general tools available for the job (drill, hammer, measuring tape, etc.). If you have a deck without any railings, it is best to build the staircase first and finish the remaining railing using the staircase posts as a starting point. The materials you will need are: pre-made stair pieces (they look like a “W” and are available at Lowe’s and Home Depot) in the right size. There are ones with only a couple steps and ones with as many as five or six. If you have a staircase longer than that, it is probably advisable to seek professional help to ensure proper structure safety. Other materials will be 2×4’s for the railings (2 per side), 1×4’s for the top of the railings, wood for the steps themselves (there are nice ones pre-made at Lowe’s) and 4×4’s for the posts, L-brackets (as many as necessary for proper support) and plenty of 1-2″ screws (better than nails in my opinion) for securing everything together.
Measure the total distance the staircase needs to cover and divide that by the per stair distance to figure out the number of steps you need to make. You will then have a good idea of how far away to put the 4×4 posts from the deck itself. That position will need to have a 24″ deep hole that is 18″ wide. Once the hole is constructed, put the 4×4 into the hole and being putting in concrete. You will need 1 or 2 bags (80 lbs. each) of concrete per hole. Just mix with water in a wheel-barrow to a thick, but pliable consistency with a shovel. Pack down the concrete as you go to ensure evenness. when you are finished loading in the concrete, check the post with a level. You will still be able to adjust it one way or the other if needed. Repeat the process for the other post.
Once the staircase outline has been attached to the deck itself with appropriate brackets and the posts are in place, you can proceed with the railings. Measure 2x4s for the top and bottom parts of the railings. Align the bottom one, stretching across the 4x4s at the appropriate angle to leave a small gap between the 2×4 and the edge of the steps. Cut and attach the board. Then measure a distance up from the attached 2×4 on the 4x4s (usually spindles are around 28″, so 30-35″ should be a good estimate depending on how much spindle you want attached to the railings). Cut and attach the second 2×4. Finally, cut and attach a 1×4 board on the top of the the entire thing to give it a finishing touch. Last of all, enjoy the beauty and safety of your new staircase railings!
