How to Build Composite Stairs

We at Bocan Residential Improvements LLC have mastered the art of stringers and composite stair builds. Within this blog, we are going to offer some free pointers on creating beautiful composite stairs that you will enjoy on a daily basis. While there are a few unique ways to building composite stairs, this is the way we install ours.

1. Step 1: Collecting your supplies.

2. Step 2: Measuring off your stringers and where they will rest.

3. Step 3: Cut your stringers.

4. Step 4: Install your stringers.

5. Step 5: Trace and cut your Fascia boards.

6. Step 6: Installing your Decking.

7. Step 7: Installing your Fascia.

8. Step 8: Railing (not explained in this blog)

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Composite Stairs Installed By BRI in Harrison City

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Collecting Your Supplies

Your exact supplies will depend on your project, what materials you are using, and whether or not you have a pad for your steps. This blog is written with the intent of a pad being excluded. For composite step installation you will (6) 2"x12" pressure treated wood boards at the desired length for your stairs. You will need 4x4 for your base support of the steps and 6x6 for your middle support of the stringers if you have a long span b/w the top and bottom support. Anywhere that posts are placed into the ground you will need concrete. Anywhere the stringers are tying into your deck you will need brackets (joist hangers and heavy-duty corner brackets. When building anything you will need to grab screws and these screws will have to be coated for exterior usage. When tying into support post you will need to use 1/2" galvanized hex head through bolts with washers and nuts. You will want to use screws in accordance with your local permit guidelines. Lastly you will need Fascia boards for each outer side of the steps and decking to be placed on your stringers as well as composite screws.

Measuring Your Stringers and the Desired Location

Each stringer step will have a run of 10" and a rise of 6.5". To calculate how many steps you need you first measure down from the top of the deck (deck boards present) 7.5" and make a level line across where your top step will be placed. This is where the top of your stringers will be installed and once the deck board is added, the distance will shorten to 6.5". From this line, you will measure down to the desired landing level of your steps and once you have this measurement (say 70") you will divide this number by 6.5" (the rise), giving you your number of stairs, 10.7. You can now determine where your steps will land by multiplying the result by 10 (the run of the steps); your steps will finish 107" from your starting point.

Composite Stair Build with Pad; Process by BRI in Jeanette

Cut Your Stringers

After calculating how many steps are needed and where they will rest, it is time to cut the stringers, you will need 6. To do so, BRI uses an "L square". This part is a little more technical and you will need to watch a video on the process (BRI will upload one soon after this blog). When cutting our measured lines, BRI uses a circle saw with a framing blade and a jig saw to finish the corners. Some businesses will cut through the corner with a circle saw, but that is simply a lack of care and patience when it comes to precision and craftsmanship.

Install Your Stringers

When installing your stringers, you need support at the top by using brackets and screws, the middle (depending on the total run and rise), and the base by placing post in concrete. You'll want to make sure your stringers are level (this is important when you go to install post for railing). You'll also want to take a large level across your steps to ensure that all of your rise and runs check out okay.

Trace and Cut Your Fascia Boards

After installing your stringers, you will want to trace your Fascia Boards against the outer stringers. This process is technical, and I encourage you to watch a video on this process (We will upload one shortly). BRI will use a square to find the angles for the top and bottom of the fascia; the top angle is generally 58 degrees while the bottom is 32 degrees. BRI will find the length of the fascia by measuring the distance of the bottom corners of the stringers when installed. After finding that measurement, BRI places the measurement on the fascia and measures the angle towards the outer edges of the board. This in-turn provides us with the full length of the stringer. After completing this process, BRI cuts off the excess fascia and clamps the fascia to the outer stringer. BRI then traces the stringer onto the fascia with a red contractor pencil (this shows up easier when cutting). When complete with the above process, BRI uses a circle saw and jig saw carefully to remove the excess fascia.

Installing Your Decking

After cutting your fascia boards, it is time to install decking. We again encourage you to watch a video on this process. BRI cuts the front board of the step first with a 45-degree angle on each side and a 1" hangover on each side. We then cut the side boards at the reverse 45-degree angles so that they fit perfectly into the front board (these will also have a 1" hangover on the outer stringer). Next BRI will measure b/w the two outer deck boards for the back deck board. BRI also covers the face of each step. To do so, we cut a deck board to be placed vertical on each side of a deck board placed horizontally b/w them. This process ensures you see no grooved edges or cut edges.

Toasted Sand Composite Deck Stairs Build Process by BRI

Installing Your Fascia

Now it is time to install your already cut fascia boards. BRI uses clamps to hold the board gently in position before applying screws. Yes, you can use adhesive but if you want thing to stay in place w/o needing to adjust over time, it is better to screw the fascia in. We advise installing screws of the same color as your fascia.

Railing

Railing install is another process itself and every railing is different. We will be uploading videos of our work shortly and this should help anyone looking for advice on railing installs.

Thank you for reading. If you are located in Westmoreland County and would like Bocan Residential Improvements to quote your deck or porch project, click here. Scroll to the bottom of the linked page to fill out a contact form. Or you can call us at 412-378-3536.

Author: Tucker Bocan