How to Frame a Bathroom Mirror

MIRRORS are often the most overlooked design element in a bathroom, leaving large, builder-grade glass sheets feeling clinical and unfinished. Framing that existing glass turns a standard piece of hardware into a custom focal point that bridges the gap between functional storage and true interior design. Successfully framing a mirror relies on precision measurement and level application. If you rush the cuts or choose heavy wood that warps in high-humidity environments, you risk the frame bowing or separating from the glass. Do it right, and you gain a sophisticated, permanent update that makes the entire room feel larger and more intentional.

1. Measure Twice, Cut Once. Measure the width and height of the glass mirror accurately, accounting for any clips or hardware holding it in place. Determine the desired width of your frame and subtract that from your total outer dimensions to get the length of each board.
2. Perfect 45-Degree Angles. Set your miter saw to exactly 45 degrees. Cut your wood trim to the lengths measured, ensuring the long point of your miter matches the desired frame length.
3. Verify Corners Meet Flush. Dry-fit the four pieces of trim around the mirror glass. Check that all four corners meet flush without gaps and the frame sits flat against the glass surface.
4. Seal All Surfaces Thoroughly. Sand all trim pieces with 220-grit sandpaper, then apply stain, paint, or a clear poly coat. Ensure the backside of the wood is also sealed to prevent moisture absorption and warping.
5. Use Mirror-Safe Adhesive Only. Run a thin bead of mirror-safe construction adhesive along the back of each frame piece. Avoid placing adhesive too close to the inner edge to prevent squeeze-out onto the glass.
6. Hold Until Fully Cured. Press the trim pieces firmly against the glass. Use painter's tape to hold the pieces in position until the adhesive fully cures, ensuring the corners remain square and aligned.