Fix Squeaks from Underneath with Shims

What happens in this clip

If you have access to the underside of your stairs, purchase wooden shims from a home center. Locate the area under the stairs where the squeak is occurring. Gently tap a wooden shim into the gap between the stair tread and the stringer or riser using a hammer. The goal is to fill the void and prevent movement. Once the shim is in place and the squeak is eliminated or significantly reduced, apply a good quality construction adhesive around the shim to seal it in place and provide additional rigidity, further preventing future squeaks.

Goal: Eliminate squeaks by shimming from the underside

What's used

Tools

• Caulk Gun
• Hammer
• Wooden Shims
• Thin wood scraps

Materials

• Construction Adhesive Titebond
• Gorilla Glue Construction Adhesive

About the full video

This project provides practical solutions for silencing squeaky wooden stairs. It covers two main methods: using wooden shims and construction adhesive for stairs with accessible undersides, and using small screws with appropriate finishing techniques for carpeted or hardwood stairs.

Step 1 of 6: Locate Squeaky Tread

From underneath the staircase, have an assistant walk up and down the stairs. Carefully listen to pinpoint the exact location of the squeak. You'll want to identify the tread (the horizontal part you step on) and the riser (the vertical part between treads) that are moving against each other or against the stringer (the support beam for the stairs). Mark the area with a pencil if necessary for easy reference.

Open this step in the guide

Every video in How to Fix Squeaky Stairs from Underneath with Shims and Glue Blocks

1. Step 1: Locate Squeaky Tread

   • 0:14–0:34 Fix Squeaks from Underneath with Shims (this video)
   • 0:13–0:20 Locate Squeaky Floor Section
   • 2:45–5:32 Identify Squeak Causes and Mark Fixings

2. Step 2: Prepare Shim Material

   • 0:14–0:34 Fix Squeaks from Underneath with Shims
   • 0:15–0:38 Shim Gaps from Underside
   • 3:09–3:51 Tighten Loose Risers with Shims

3. Step 3: Apply Wood Glue

   • 6:40–7:13 Apply Wood Glue (Back Risers)
   • 0:22–0:34 Apply Wood Glue
   • 6:22–6:49 Apply 5-Minute Wood Adhesive

4. Step 4: Insert and Secure Shims

   • 4:46–5:44 Attach Support Blocks and Secure Wedges
   • 4:08–4:28 Final Gap Filling and Tread Reinforcement
   • 3:09–3:51 Tighten Loose Risers with Shims

5. Step 5: Test for Squeaks

   • 4:28–5:00 Test the Repaired Stairs
   • 0:14–0:34 Fix Squeaks from Underneath with Shims
   • 5:45–6:01 Test the Repaired Stairs

6. Step 6: Clean Up

   • 10:52–11:00 Clean Up Mess
   • 13:42–14:26 Clean Glue Squeeze-out