Shower and Tub Leaks: Signs of Water Damage and What to Do

By Noah Miller, founder of AZ Water Damage Help · Published October 20, 2026

Showers and tubs use a lot of water every day. When grout cracks, caulk pulls away or a pipe drips inside the wall, that water goes where you cannot see it. A shower leak can soak the subfloor, the wall behind the tile and the ceiling below for months before anyone notices. This guide covers the signs, how to find the source and what to do next.

What are the signs of a leaking shower or tub?

• Loose or cracked tile on the shower walls or floor.
• Missing or dark grout and caulk, especially where the tub meets the wall.
• A soft or spongy floor next to the tub or shower.
• Peeling paint or swollen baseboards on the other side of the shower wall.
• A stain on the ceiling below an upstairs bathroom.
• A musty smell that stays after the bathroom dries out.

Many of these signs also point to other hidden leaks. See our list of signs of hidden water damage.

Where do shower leaks come from?

Common shower and tub leak sources

Source	When it leaks
Grout, caulk or cracked tile	Only while the shower is running
Shower pan or tub drain	Only while water is draining
Valve or shower arm inside the wall	While the shower is on, sometimes all the time
Supply pipe inside the wall	All the time, even with the shower off

Arizona's hard water leaves mineral buildup on valves and fittings. Over time this can wear out seals and cause slow drips inside the wall.

How can I find the leak?

1. Turn off every faucet and fixture in the home, then watch your water meter. If it moves, a supply pipe may be leaking.
2. Fill the tub with a few inches of water and mark the level. If it drops with the drain closed, the drain or overflow may leak.
3. Run water only on the tile walls, not the drain, and check below or behind for new damp spots.
4. Look for gaps in caulk where the tub meets the wall and at corners.

A plumber can test the drain and pipes. A restoration crew can use moisture meters and a thermal camera to show how far the water has spread.

What should I do once I find a shower leak?

1. Stop using that shower or tub until the leak is fixed.
2. If a pipe is leaking all the time, close the main water shut-off.
3. Take photos of stains, loose tile and damaged floors.
4. Call a plumber to repair the leak.
5. Have the wall and floor checked for moisture and dried.

Re-grouting over a wet wall can trap moisture and lead to mold. Mold can start growing in 24 to 48 hours, according to the EPA. Learn how fast mold grows after water damage.

Can the bathroom floor and wall be saved?

Often parts of it can. Tile itself handles water well. What fails is what is behind and under it: drywall, backer board, wood subfloor and insulation. If these are only damp, they can often be dried. If they are soft, crumbling or moldy, they usually need to be removed. A short leak caught early costs much less to fix than one that has run for months.

Does insurance cover a leaking shower?

Many policies cover sudden water damage, such as a pipe that bursts inside the wall. Slow leaks from worn grout or caulk are often treated as wear and tear and may not be covered. Check your policy and see our guide to insurance coverage for water damage.

Frequently asked questions

Sources

• EPA: Mold
• EPA WaterSense: Fix a Leak Week
• IICRC (Institute of Inspection, Cleaning and Restoration Certification)

Related guides

• 9 Signs of Hidden Water Damage in Walls and Floors
• Toilet Overflow Water Damage: What to Do and When It Is Unsafe
• Musty Smell After Water Damage? What It Means and How to Get Rid of It
• Water Stain on Your Ceiling? Causes and What to Do in Arizona

Water damage services

• Burst pipe water damage
• Ceiling and roof leak water damage
• Water damage mold removal
• Insurance claim help