Leaking Shower Door
Updated February 20, 2026
Water escaping around, under, or between shower door panels -- worn seals, misaligned doors, bad caulk, or spray hitting the gaps directly. Most fixes take under an hour and cost less than $30.
Overview
More than an annoyance. Repeated moisture damages flooring, rots subfloor, grows mold behind baseboards, and can compromise framing. Shower doors rely on seals, sweeps, magnetic strips, and caulk. When any of those fails, water finds its way out. Common leak points: bottom (sweep meets threshold), sides (frame meets wall), gap between panels. Almost always fixable without replacing the door. Replacement seals and sweeps are cheap and widely available.
Symptoms
- Puddles on the floor outside the shower after every use, concentrated near the door base
- Dripping from the bottom edge during the shower -- stream or steady drip running down the outside face
- Water escaping between sliding panels -- magnetic seal or overlap no longer holding tight
- Leaking where the frame meets the wall or curb -- caulk cracked, separated, or missing
- Water stains, mold, or mildew on the floor, baseboards, or vanity -- slow leak that has been going for a while
- Door does not close fully or sits unevenly -- misalignment creates gaps
Common Causes
- Worn or cracked bottom sweep -- the vinyl, rubber, or silicone strip along the bottom edge hardens, cracks, or warps from water and temperature. Once it no longer makes consistent contact with the threshold, water runs underneath.
- Deteriorated side seals or magnetic strips -- vinyl dries out and shrinks, magnetic strips lose strength or peel off. Sliding doors, frameless hinged doors -- same failure on both.
- Failed caulk at frame-to-wall junction -- shrinks, cracks, or peels away over time. Mold in the joint makes it easy to spot. Wrong caulk type (latex instead of silicone) or caulking over dirty surfaces accelerates failure.
- Misaligned door -- hinges loosen, wall anchors pull, rollers wear out, track bends. Creates uneven gaps the seals cannot cover.
- Spray hitting the gaps directly -- even with perfect seals, a shower head aimed at the door gap forces water through. Repositioning the head or adding a splash guard fixes it.
What You'll Need
How to Fix It
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Identify the Leak Location
Close the door, run the shower, watch from outside. Bottom, sides, panel overlap, frame-to-wall junctions. Water runs along surfaces before dripping, so the drip point may not be the source. Trace it back. Bottom sweep: puddle centered under the door. Panel gap: water offset to one side. Frame caulk: water running down the wall outside.
Tip: Dry paper towels along the outside base before running the shower. Check which ones get wet after a few minutes. Precisely identifies even small leaks. -
Replace the Bottom Door Sweep
Slide the old sweep off the glass edge (most are a channel that clips on). Measure length and glass thickness (1/4, 5/16, or 3/8 inch). Matching replacement from hardware store or online. Trim to length with scissors, slide on, test. Should make light, consistent contact with the threshold -- snug enough for no visible gap, not so tight the door is hard to close.
Tip: Bring the old sweep for matching. Different profiles (flat, angled, finned) and glass thicknesses. Exact match is best. If unavailable, universal adjustable sweeps work for most doors. -
Replace Side Seals or Magnetic Strips
Peel the old strip off (adhesive-backed or press-fit). Clean the glass edge with rubbing alcohol. New strip to length, press into place. Magnetic strips: correct polarity so they attract when panels overlap. Hinged door side seals: same process, remove old from the channel, press in new.
Tip: Magnetic strip seems weak but is only a few years old? Clean both surfaces with rubbing alcohol. Soap scum and mineral deposits reduce grip significantly. -
Recaulk the Frame-to-Wall and Frame-to-Curb Joints
Razor blade or oscillating tool to remove all old caulk. Clean with rubbing alcohol, let dry. Continuous bead of 100% silicone (not latex, not acrylic -- silicone is flexible, waterproof, mold-resistant). Painter's tape both sides for clean lines. Smooth with a wet finger or caulk tool. Tape off immediately. 24 hours cure before using the shower.
Warning: Do not caulk the inside bottom of the frame where it meets the curb. That joint stays open (or has weep holes) so water inside the frame channel drains back into the shower. Sealing it traps water and causes overflow onto the floor. -
Adjust or Repair the Door Alignment
Hinged: tighten hinge screws. Holes stripped? Remove screws, fill with toothpicks and wood glue, let dry, reinstall. Sliding: check rollers top and bottom. Most have an adjustment screw to raise or lower the door. Adjust until level with consistent seal contact. Rollers worn or wheels flat? Replace them.
Tip: After adjusting, check the gap at top, middle, and bottom. Should be uniform. Narrows at one end? Door is not plumb, needs more adjustment. -
Redirect the Shower Spray
Seals and caulk fine but water still escapes? Redirect the spray. Angle the head toward the back wall instead of the door. Handheld on a slide bar: position to minimize spray at the gaps. Fixed head that cannot angle away: install a splash guard (clear acrylic strip, $5-10) on the inside near the problem area.
Tip: Rain-style overhead heads send water straight down -- less likely to hit door gaps. Wall-mounted heads aimed horizontally are the worst offenders, especially in small showers.
When to Call a Pro
Call a glass company if the panel is cracked or chipped, if the frame is corroded and needs replacement, if the door was improperly installed (not plumb, not level), or if hinges are pulling out of the wall and need structural reinforcement. Seal and caulk repairs are DIY. Frame and hardware issues may need a pro.
Prevention Tips
- Inspect sweeps and side seals every 6-12 months. Replace at first sign of cracking or hardening -- by the time the leak is obvious, the floor has been getting wet.
- Recaulk frame-to-wall joints every 2-3 years even if the caulk looks fine. Silicone develops invisible micro-cracks that let water through.
- Squeegee the glass after every shower. Removes water before it runs down past the seals.
- Clean the track on sliding doors. Soap scum and mineral deposits prevent full closure and block weep holes.
- Do not slam the door. Loosens hinges, knocks rollers off track, accelerates seal deterioration.
- When replacing seals, choose silicone over vinyl. Silicone resists hardening and cracking much longer in the wet, warm environment.