Skip to Content

How Many Screws Per Stair Tread?

When attaching your stair tread, you need adhesive or fasteners like screws to secure them in place. Would you like to know how many screws you might use on it? To aid you with your query, we have done some research, and here’s what we discovered.

Disclosure: We may get commissions for purchases made through links in this post.

The screws vary according to the width of your tread. You need more screws as your tread length increases. But typically, two fasteners are used at each stringer for each stair tread.

In this article, we’ll dig deeper into the screws fastened to the stair tread. Also, we’ll share some differences between screws and nails, the installation of the stair tread, and securing loose treads. There's more information ahead, so keep on reading.

How Many Screws Per Stair Tread?

Screwdriver screw in a wood oaks plank

When installing the tread, it is recommended to utilize 3" corrosion-resistant, composite wood deck screws for simplicity of installation, as they help reduce the typical "mushroom" effect that occasionally happens when using regular fasteners.

Additionally, they can minimize the need for countersinking and pre-drilling. When using additional composite or wood screws, always drill a pilot hole first and countersink at the ends of the boards. Avoid over-tightening screws in the vicinity of board ends.

Stair tread surfaces must be level with screws as they are driven. To ensure that the screws are precisely aligned, use a square. At each stringer, use two screws per stair tread. However, this can vary depending on the width of your tread.

If you're using a 4” to 6” wide tread per step, you need at least two screws in each stinger you have. While you need three screws if you're using  12” wide treads fastened into each stringer.

What Is The Difference Between Screws And Nails?

Some nails appear to weaken over time and no longer have the same gripping force as a screw. Both will eventually deteriorate through the oxidizing or rusting process. 

Using nails will undoubtedly be quicker and more effective when constructing a flight of stairs.  Screwing a flight of steps together would be very time-consuming and difficult.

Squeaky stairs are a major issue within staircase design, and the majority of stair squeaks are caused by loose nails.

Fastening two pieces of wood with an angled nail is a terrific way to provide a strong holding force.  However, a screw will break with less force than a nail if a horizontal force is applied to a screwed stair tread. You would need to screw and nail the stair treads in order to achieve the best of both.

Using screws and nails properly is important since they both have advantages. Remember that there are many different sizes, lengths, and metals available for screws and nails. 

To avoid oxidation or rusting, try to use galvanized nails and screws on outside surfaces. As long as moisture won't be an issue, practically any type of screw can be used within a house.

How to Install Stair Treads?

Wooden Stair Treads

Technically speaking, installing steps or stair treads for a porch, deck, or shed is not pretty difficult. Anyone with rudimentary carpentry abilities may make the required cuts and put the parts together. 

However, building stairs is likely the most difficult project that do-it-yourselfers will ever try. Additionally, you cannot simply install the stair tread without following a few instructions, which are covered below:

Stair treads to protect the old and worn stairs and a beautiful curved banister with spindles, How Many Screws Per Stair Tread?

1. Measure the Total Rise

Yellow tape measure on green background

The total rise is the overall height of the stairs. To get it, measure from the top all the way down using a tape measure. Make certain to account in your measurement if you don't want the top step to be exactly level with the area where the stairs begin.

Click here to see this tape measure on Amazon.

2. Calculate The Number Of Risers

To get this, divide the total rise by the actual rise per step. Usually, there is a rise of 6.5” to 8” every step, even if the height of the rise itself presumably varies slightly.

3. Calculate The Number Of Treads

Typically, there is one less tread than risers. Simply subtract one from the total number of risers to estimate the number of treads.

4. Measure The Total Run

Every step's run (tread width) ought to be at least 10” and ideally no less than 9”. The average foot can step comfortably and safely in this sized space. To determine the total run or the total width of the stairs, multiply the number of treads by its width per tread width.

5. Measure The Length Of The Stringers

Carpenter Measuring a Wooden Plank using a tape measure

Stringers are wooden planks that will run perpendicular to the length of the steps to support them. You'll eventually attach your treads and risers to these. Calculate their length in the same way you would the hypotenuse of a right triangle.

6. Determine How Many Stringers You'll Need

A large staircase will require a lot of stringers underneath to keep it uniformly supported and avoid allowing the stairs to sag or bow as you walk on them. You can have two stringers for a very narrow staircase but it is advisable to start with three stringers and increase as needed.

Place the stringers around 16” apart for safety reasons. Since they are considerably easier and more comfortable to manage, wider staircases are often preferred to narrower ones.

7. Layout And Cut The Stringers

Layout your stringer on a piece of lumber. Based on the height and depth of your stairs, they will sit at a certain angle, necessitating the modification of the tops and ends. 

Indicate the height (riser) and depth (tread) of your steps using a carpenter's square. Along the length of the lumber, use a portable circular saw to cut the tread-and-riser notches after you've drawn them all. Make the subsequent stringers based on the initial stringer as a model.

Click here to see this carpenter's square on Amazon.

Click here to see this circular saw on Amazon.

8. Install The Stringers

You can fasten the tops of the stringers to the building in numerous ways. One quick solution is to fasten metal joist hangers to the deck supports or floor joists. Put one edge flush with the end of the stringer and the other against the joist, then drive screws into the holes in the joist hangers.

Place a solid foundation for the stringer bottoms, such as wood flooring, concrete, or even a block of treated lumber on top of the gravel. To secure and stabilize the stringers, install the bottom riser or toe board first. 

9. Install The Risers

Use a power miter saw to quickly and precisely cut the risers to the proper length. With 2 ½” trim-head screws, which have tiny heads that protrude below the surface, secure each riser to the stringers. 

Click here to see this miter saw on Amazon.

Although you don't need them, attaching these boards vertically with screws can improve the stairs' appearance and lengthen their lifespan.

10. Install The Treads

If you want your stairs to have a tiny overhang at the ends, cut the lumber just wider or slightly longer than the tread run's width. When possible, use glue or construction adhesive on all of your stringers before installing the tread.

Click here to see this construction adhesive on Amazon.

Use 3” trim-head screws to secure the treads over each stringer. If you are using more than one plank or tread per step, space the treads apart by ⅛” to ¼”. As you work your way up the staircase, continue placing treads. 

Click here to see these 3” deck screws on Amazon.

Before installing the treads, the 4x4 posts that support the stairway railing are frequently attached to the stringers.

11. Apply Exterior-Grade Finish

If necessary, paint, varnish, or seal your steps. If the stairs are going outside, you might want to treat the wood against the elements. Finishing the stairs will protect them from normal wear and tear and enhance the finished product, even if they are being built for indoor use.

For staircases, almost any stain, varnish, or paint will do. On the steps, you can also use non-slip sticky patches or non-slip paint.

Click here to see this anti-slip paint on Amazon.

To see how the installation is done, a video on YouTube is shown below. 

How Do You Secure Loose Stair Treads?

If the front of your stair is squeaking, tighten the fitting with a few screws. #8 screws are an excellent size for this purpose and are readily available at any home improvement store. Drill three properly spaced pilot holes across the tread's front where it meets the riser to begin. 

Click here to see this #8 screw on Amazon.

The three screws should then be drilled into the tread, being sure to tuck them just beneath the surface. Someone's bare foot will be hurt if a screw is left protruding out of the tread. 

Once the screws are in place, cover them up and fill in the small indentations with a small amount of wood filler in the corresponding color.

However, use 8d or 10d nails to secure the tread securely into its stringer if the squeak originates from the back or the side of the tread and you want a more long-lasting fix than lubrication. 

Click here to see this 8d nail on Amazon. 

On the side of the tread closest to the wall, begin by drilling tiny pilot holes. They should be positioned roughly two inches apart and bored at oblique 45-degree angles so that the nails you add are pointed away from one another. 

Wrap Things Up

Stair treads to protect the old and worn stairs and a beautiful curved banister with spindles

We hope this helps you understand the significance of screws in stabilizing your stair tread, especially how many screws you should fasten. Just keep in mind to drive it properly from the tread board into the stringer. Additionally, level them with the board or countersunk below the surface of the tread.

Before you go, check out some related topics that we have below.

How Much Floor Space Do Stairs Typically Take?

Where Should Stairs Be Located In A House (And Can You Relocate Them)?