The Staircase - Mudroom Update

The Staircase: DIY Garage Mudroom Update

I'm back today with another exciting update on our garage-to-mudroom conversion! 

If you've been following along, you know we've been working hard to turn a cluttered corner of our garage into a functional, organized entry. This time, I'm spilling all the details on a major milestone: how to build a DIY staircase.

The Starting Point: From Hazardous to Functional

If you're new here, let me give you the back story. This is the main garage in our home, and for years, the platform you see in the picture below was a total "catch-all" for shoes, sports gear, and miscellaneous clutter. 

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In my previous post (which you can catch up on HERE), I shared how we built the walls for the new mudroom. At the end of this post, you'll find the links to all the work tackled so far.

While the room was taking shape, we were still using the original stairs, and let me tell you—that top step was a real hazard! 😬 It was definitely time for a safe, sturdy upgrade.

Understanding Staircase Building Codes

Before we picked up a single tool, we did our homework. When building any staircase, staying up to code is non-negotiable for safety. 

Here are the standard measurements we kept in mind:

• Minimum Staircase Width: 36 inches

• Maximum Riser Height: 7 ¾ inches

• Minimum Tread Depth: 10–11 inches

Pro Tip: These guidelines ensure every step is uniform, preventing trips and falls. Never bypass these rules!

Step 1: Installing the Stringers

To keep things simple and accurate, we opted for pre-cut pressure-treated stringers. These are the three vertical supports that hold your treads and risers. Buying them pre-cut is a huge time-saver and ensures your steps are already up to code.

We carefully measured the height to ensure they were perfectly level before securing them.

| Four-Step Stair Stringer | Level |

CLOSE STRINGERS

For a finished look, we added closed stringers using 1x12 primed pine on both sides of the staircase. 

We had to get a little creative to make the most of our single 8-foot board—it was like putting together a puzzle!

Once cut to size, we clamped them in place and secured everything to the platform and floor using a combination of:

• Construction screws

• Brad nails

• Liquid Nails (for maximum stability)

On the right-hand side, we also added a 2x10 and Sheetrock to tie it into the existing structure.

The side that didn't show much was the one we had to put together like a puzzle! :D

A 2 x 10, and Sheetrock were also added on the right-hand side of the staircase.

Here, an eye-bird view.

Step 2: Fitting the Treads and Risers

For the staircase treads, I found beautiful 11-1/2" x 48" red oak boards at Home Depot. They are incredibly strong and solid. We used a miter saw to cut them to the exact width of our staircase.

| Red Oak Engineer Tread |

For the staircase risers, we used 1/2-inch plywood cut to size on the table saw. 

At this stage, we only "dry-fitted" everything to ensure a perfect fit before moving on to the finish.

It all looked really nice! 

However, the treads and risers were removed to finish them.

Step 3: Sanding and Staining Red Oak

This was the hardest part of the project—deciding on a stain! My goal was to neutralize the oak's natural red undertones while keeping the wood light and modern.

I first gave the staircase treads a light sanding and dusted them very well.

| DeWalt 5-In. Variable Speed Sander |

After testing several stains (White Wash, Classic Gray, Sunbleached, and Dark Walnut) on leftover scraps, I found the winner: Varathane Weathered Gray.

• The Result: One coat was all it needed to achieve that perfect earthy tone without looking like paint.

| White Wash | Classic Gray | Sunbleached | Weather Gray | Dark Walnut |

• The Prep: I gave the treads a light sanding with 220-grit sandpaper for a buttery-smooth finish.

For the risers and closed stringers, we went with a classic, clean look: two coats of Behr White in a semi-gloss finish.

| Behr White - Semi-Gloss |

Step 4: Final Installation

With the paint and stain fully cured, it was time for the final assembly.

• Prep for Adhesion: We used a small metal brush to roughen the contact points on the stringers, then vacuumed away all dust. This helps the wood glue bond better.

• Glue and Set: We applied Titebond wood glue to the stringers and set the first tread.

| Titebond Wood Glue |

• Layering: We alternated between installing a tread and then the riser behind it.

• Secure: A few 2" brad nails were driven through the boards into the stringers to hold everything while the glue dried.

| Ryobi Cordless Brad Nailer |

The Finished Look (For Now!)

We also took the time to cap off the side stringer with 1x3 pine for a professional finish and—finally—installed the pre-hung door to the mudroom!

I've already started painting the walls, and even though I still need to do the "cut-in" work around the door and window, the transformation is incredible. It's looking better every single day!

| JELD-WEN Door | Kwikset Door Handle Set |

Installing the door was easier than what I thought. 

What's next? 

We'll be installing the flooring inside the mudroom and adding a protective topcoat to these beautiful stairs. Stay tuned for the next update!

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Here are all the projects that were tackled during this mudroom build:

THE MUDROOM PLAN

DIY - GARAGE PLATFORM

FRAMING THE MUDROOM

THE STAIRCASE

SLATE TILE INSTALL

DIY - CABINETS

DIY - BACK CABINET & SLIDING DOOR

DIY - MUDROOM BENCH

DIY - FAUX CABINET

THE MUDROOM REVEAL

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