How long does bathtub caulk last?

Silicone caulk typically lasts 5–10 years. Acrylic caulk lasts 2–5 years. Replace it sooner if you see cracking, peeling, or black mold that won't scrub off.

Should I use silicone or acrylic caulk for a bathtub?

Use 100% silicone for tub surrounds — it stays flexible, resists mold better, and won't crack when the tub flexes. Acrylic is easier to apply but less durable in wet areas.

How long does caulk need to dry before I can use the shower?

Silicone caulk needs 24 hours to cure fully before water exposure. Some fast-cure formulas claim 3–4 hours — check the label, but 24 hours is the safe rule.

What if caulk keeps cracking in the same spot?

Tubs flex when filled with water. If caulk cracks repeatedly, fill the tub before applying caulk so it's already in the expanded position, then let caulk dry before draining.

How to Caulk a Bathtub (The Right Way, Step by Step)

Old bathtub caulk cracks, discolors, and grows mold — and no amount of scrubbing fixes it once the seal breaks. The good news: recaulking a tub is a genuine beginner job. You need about an hour, $10 in supplies, and patience while it dries.

This guide covers everything: removing old caulk completely, prepping the surface, and applying a clean new bead that lasts years.

What You'll Need

Caulk remover tool or utility knife
Plastic scraper
Isopropyl alcohol (90%+) or tub-and-tile cleaner
100% silicone caulk (mold-resistant formula)
Caulk gun
Masking tape (optional but highly recommended)
Paper towels and a damp cloth

Best caulk picks:

GE Sealants 100% Silicone Caulk — trusted brand, flexible, mold-resistant
DAP Kwik Seal Plus — good acrylic/silicone blend for easier tooling

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Step 1: Remove Every Bit of Old Caulk

This is the step most people rush — and why new caulk fails in a year. New caulk won't bond properly over old caulk, even a thin residue layer.

Use a caulk remover tool or utility knife to score along both edges of the old caulk bead. Grab an edge and pull. For stubborn bits, work the plastic scraper underneath and push forward.

A chemical caulk remover (like Goo Gone Caulk Remover) can soften hardened silicone after 2–3 hours if it won't budge.

You're done removing when: you can run your fingernail along the joint and feel the bare tub surface, not any sticky residue.

Step 2: Clean and Dry the Surface

Wipe the joint with isopropyl alcohol. This removes soap residue, oils, and any caulk remover chemical — all of which will prevent bonding.

Let it dry completely. In a humid bathroom this can take 30–60 minutes. Speed it up with a hair dryer on low, keeping it moving. The surface must be bone dry before you caulk.

Step 3: Fill the Tub With Water Before Caulking

This is the step most tutorials skip. A standard bathtub flexes slightly under the weight of water. If you caulk with an empty tub, the caulk stretches when you fill it and cracks within weeks.

Fill the tub to normal water level, then do your caulking while it's full. Let caulk cure for 24 hours before draining.

Step 4: Apply Masking Tape (Recommended)

Run two strips of masking tape — one on the tub surface, one on the tile/wall — leaving the joint gap exposed. This gives you a clean straight line and makes cleanup easy.

Cut the tape at the corners so it lies flat.

Step 5: Cut the Nozzle and Load the Caulk Gun

Cut the nozzle at a 45-degree angle. The opening should be about the width of the joint — typically 3–4mm. Smaller is better; you can always add more, but a fat bead is hard to tool neatly.

Load the cartridge into the gun and depress the plunger until caulk just reaches the tip.

Step 6: Apply the Caulk Bead

Hold the gun at 45 degrees to the joint. Apply steady, consistent pressure as you pull (don't push) the gun along the joint in one smooth stroke per section. Move at a pace that keeps the bead slightly overfilled — you'll smooth it down in the next step.

Do one full wall section at a time so you can tool it before it skins over.

Step 7: Smooth the Bead

Dip your finger in water (silicone tools better wet). In one smooth stroke, run your fingertip along the bead, pressing gently to push it into the joint and create a concave profile.

Remove excess caulk from your finger onto a paper towel, not back into the joint.

If you used masking tape, peel it immediately — before the caulk skins — pulling it back at a 45-degree angle.

Step 8: Let It Cure

Leave the tub dry for at least 24 hours. Post a reminder on the bathroom door. Silicone that gets wet before it cures loses adhesion and will peel.

Most silicone caulks are fully waterproof at 24 hours; check your product label for the exact time.

Common Mistakes to Avoid

Caulking over old caulk — new caulk won't stick. Always remove everything first.

Caulking a dry tub — always fill the tub before applying. The flex-and-crack cycle is the top reason DIY caulk jobs fail in a month.

Using paintable latex caulk in a wet area — latex caulk will mold quickly in a tub surround. Use silicone or a silicone-blend formula.

Applying too thick a bead — a thin, well-tooled bead is stronger and looks better than a fat lumpy one.

How Often Should You Recaulk?

Inspect caulk every year during your spring cleaning. Signs it's time to replace:

Visible cracks or gaps (even hairline)
Black spots that don't scrub off (mold inside the bead)
Caulk pulling away from the tile or tub
Soft, spongy texture when pressed

Silicone typically lasts 5–10 years with proper installation. Acrylic lasts 2–5 years.