FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Fine Homebuilding Project Guides

Decks

Guide Home
  • Design & Planning
  • Tools & Materials
  • Footings & Foundations
  • Framing a Deck
  • Installing Decking
  • Installing Railings
  • Deck Stairs
  • Custom Details
  • Finishes, Repairs, and Maintenance
  • Complete Deck Builds
How-To

Securing Deck Stair Treads

Add a filler strip to attain a comfortable tread depth.

By Scott Grice
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Installing treads is much like installing decking. Although with the stair treads, depending on the project details, you may have to decide on a tread pattern. Typical decking is 5-1/2 in. wide, but combining two boards is still a little narrow for a comfortable tread depth, especially when considering the overhang at the tread nosing. For wood decking, adding a 1-in. to 2-in. filler strip between the treads easily solves this issue.

There are a variety of ways to pattern the treads to make them wide enough for comfortable deck stairs. Adding a filler strip in the middle is both decorative and functional.

For composite decking, the solution can be a little more involved. For example, capstock decking looks different on the inside, so ripping a tread will show an obvious cut line. Similar difficulties arise with textured composite decking and metal decking. Some manufacturers have tread stock that solves this issue. Alternatively, placing the filler strip at the back to hide the cut face is another way to deal with this. 

Installing top-down fasteners

The most common way to secure decking on stairs is to face-screw the decking boards. Even if the main portion of the deck is secured with hidden fasteners, top-screwing the stair may still be a good option because hidden fasteners are sometimes difficult to use with stairs. Some composite decking types have tabs that fit over the screw holes to improve the appearance. In hardwood decking, you can hide the screw holes with plugs.

Wood plugs take a little extra work to install but effectively conceal fasteners. The key to success is ensuring you have a sharp Forstner bit to bore the countersink holes.

Before installing treads with top-down fasteners, first determine the amount of the overhang 1. Remember to account for the riser thickness when measuring the overhang. With the overhang set and the inside tread board in position, measure the width of the filler strip 2. Before installing the filler strip, round over the cut edge to give it a finished look 3.

To install the treads, align the inside board with the proper overhang by measuring back under the stringer 4. This distance will vary depending on your construction details.

1. Place the nosing tread in position with the correct overhang. Remember to account for the thickness of the riser.
2. Measure the gap between the treads and then subtract two times the standard decking gap to calculate the width of the filler strip.
3. Rip the filler strip to width and round over the cut edges.
4. Position the inside tread with the correct side overhang. Make a mark on the tread where it sits over the stringer’s centerline.

 

What can go wrong

If you secure the deck board at the top of the stair permanently, the nosing overhang will force you to drive the fastener at an angle. Instead, leave the deck board loose so you can move it out of the way and drive the fastener straight down.

 

Another way to refine the deck’s appearance is to carefully line up the visible fasteners. Stack the treads with the ends aligned and transfer a layout mark that represents the stringer’s centerline 5. Before drilling any holes, mark the fastener locations and set up the boards for one tread to check the spacing 6. Once the distance between tread boards is established, cutting spacers is an easy way to keep the gaps uniform for the entire run of steps 7.

Align a gauge or Speed Square to the mark made in step 5 and make a slight indent with an awl 8. In hardwoods, the indent keeps the drill bit from wandering as you begin the hole. Drill the pilot hole using a 2-in-1 bit 9. Secure the tread boards before moving on to install the adjacent pieces 10. Align the filler strip with a spacer positioned over the stringer 11 and with a Speed Square to flush the ends 12.

5. Transfer that mark to the other tread pieces. Make sure the ends are aligned when doing this.
6. Mark the fastener spacing on one set of treads before you start drilling to check that the pattern is both functional and pleasing.
7. Rip spacers to the gap dimension. Hardwood spacers are more accurate and efficient than trying to measure the gap.
8. Make a pilot indentation with an awl. This marks the location and also prevents the drill bit from wandering off layout.

 

9. Drill both the pilot hole and countersink at the same time with a two-step drill bit

10. Secure the inside tread to the stringer with screws. Be careful not to overdrive the fastener.
11. Position the spacers between the treads to maintain a consistent gap.

12. Flush the tread ends with a square to eliminate any variation of the treads that would detract from the overall appearance.

Repeat the process to align and secure the outer tread board 13.

Working from the bottom tread up has the advantage that you have a finished platform to work from 14. To align the treads from one step to another place a square to reference the upper step with the lower step 15. After all the treads are installed, fit the risers, leaving any gap hidden under the overhang 16. Install the risers using the same method of aligning, drilling pilot holes, and securing as you did with the treads 17.

Trade secret

A 2-in-1 pilot bit will drill a pilot hole and countersink for the head. It also has an adjustable collar to stop the countersink depth where you want it.

 

13. Secure the outside tread to the stringer; do not split the stringer.
14. Work up from the bottom when securing treads.
15. Align the ends of the treads with a square to keep a consistent layout.
16. Fit the risers after all the treads have been installed. Orient any gap to the top where it will be hidden by the overhang.

17. Secure the risers using the same layout methods you used with the treads.

Notch decking around posts

Carefully fitting deck boards around posts and other objects will give the deck a professional look. You can do this without using a tape measure; instead, mark the tread in place referencing the side of the post or other obstruction.

1. Place the board you want to notch against the post with the end registered to its final installed position. Using a Speed Square, mark the perpendicular cutline.

2. Use a scrap piece of post material to mark the cut line that will be against the post’s forward face.
3. Mark the waste material with an X before moving the board. This will help you avoid the error of cutting to the wrong side of the line. It happens!
4. Use a chopsaw to make the partial perpendicular cut. The blade will not cut completely in the corner but you will finish the cut in the next step.
5. Make the adjoining cut with a jigsaw and finish both cuts at the corner.

6. Round the upper edge of the fresh cut with a trim router fitted with the same round-over bit that you used for easing the end cuts.

Test-fit the board and make any adjustments necessary.

 

Fine Homebuilding Recommended Products

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

Cepco BoWrench Decking Tool

This tool makes straightening deck boards a breeze during installation.
Buy at Amazon

Angel Guard Deck Demon

Demo has never been easier with the deck demon. The tool keeps the worker in an upright position and uses leverage to remove decking from framing, a must have tool for demo.
Buy at Amazon

MicroFoam Nitrile Coated Work Gloves

These gloves are comfortable and have a good grip, making for splinter-free work.
Buy at Amazon
Previous: How to Avoid Sloped Stringers on Deck Stairs Next: How to Install Deck-Stair Treads

Guide

Decks

Chapter

Deck Stairs

Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Decks

Decks

Hundreds of articles and videos by top deck-building pros on how to design and build a beautiful, sturdy, and safe deck

View Project Guide

View All Project Guides »

Become a member and get unlimited site access, including the Decks Project Guide.

Start Free Trial

Design & Planning
  • Basic Design Options
  • Generating Plans
  • Calculating Deck Loads
  • Code Compliance
Tools & Materials
  • Deck Building Tools
  • Foundation and Framing Materials
  • Decking Materials
  • Fasteners and Hardware
Footings & Foundations
  • Choosing a Foundation
  • Sizing and Laying Out Footings
  • Excavation
  • Pouring the Foundation
Framing a Deck
  • Framing Overview
  • Installing the Ledger
  • Setting Posts and Beams
  • Installing Joists
Installing Decking
  • Decking Basics
  • Installation Process
  • Adding Fascia and Other Decorative Elements
Installing Railings
  • Installing Deck Railing Posts
  • Building Wood Rails and Balustrades
  • Non-Wood Railing Options
  • Installing Nonwood Balustrades
Deck Stairs
  • Deck Stairs Overview
  • Laying Out, Cutting, and Installing the Stringers
  • Installing Treads, Risers, and Stair Railings
Custom Details
  • Benches, Planters, and Privacy Features
  • Pergolas
  • Lighting
Finishes, Repairs, and Maintenance
  • Deck Finishes
  • Cleaning and Refinishing
  • Inspection and Repair
Complete Deck Builds
  • Grade-Level Decks
  • Raised Decks

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data