Failed caulk does its damage out of sight. The visible problem is yellow or cracked caulk around the tub, and most homeowners assume it is cosmetic. The hidden problem is water sneaking past the failed seal, soaking the drywall, swelling the subfloor, and growing mold inside the wall cavity for months before any damage shows from the outside. By the time the bathroom looks bad, the wall behind it might be a tear-out repair instead of a caulk job.
Recaulking is one of the most useful prevention jobs in any home, and it sits squarely inside my general repairs work. It is also one of the easiest DIY jobs to do badly. This guide covers both sides.
When DIY caulk replacement is fine
If the existing caulk is just yellowed or stained but the substrate underneath is solid, recaulking is a perfectly DIY-able job for an afternoon. The skill is in the prep, not the application. Cut the old caulk out completely with a utility knife and a caulk-removal tool. Vacuum and wipe the joint with isopropyl alcohol. Let it dry fully. Lay painter's tape along both sides of the joint to define a clean line. Apply a kitchen-and-bath silicone (not latex, not 'silicone-blend') in a smooth bead. Tool the bead with a wet finger or a caulk-finishing tool. Pull the tape immediately while the silicone is still wet. Let it cure 24 hours before water hits it.
When you should call instead
Once water is already getting through, new caulk only covers the problem. In these cases the caulk is the symptom and the real repair is bigger.
- The drywall behind the tile feels soft when pressed. Water has already gotten through.
- The grout between tiles is cracked or missing in the wet zone, not just the caulk joint.
- The tub or shower base flexes underfoot. The subfloor may already be compromised.
- There is a musty smell when the bathroom is closed up. Mold is likely already growing somewhere.
- You see staining on the ceiling of the room directly below.
- The caulk has been replaced before and failed again within a year.
If it is the grout that has cracked, my guide on whether to regrout or retile a shower shows how to tell a worn joint from water behind the tile.
Why the wrong caulk causes the same problem twice
Latex caulk is cheaper and easier to apply but breaks down in the constant wet-dry cycle of a tub or shower. It is fine for trim and baseboards. The bath needs something tougher. Caulk sold as 'siliconized' is often latex with silicone added. DAP's Kwik Seal Ultra, for one, is a siliconized latex. Read the tube and look for 100% silicone, sold as kitchen-and-bath caulk. It is harder to tool clean, but it lasts far longer in a wet spot. My default is GE's Advanced Silicone 2 Kitchen & Bath, which GE sells as 100% silicone.
Every job I take gets a written scope before I start, so the price is agreed in advance and the list stays the list.
Want me to take this one on? My page on home repairs covers what the visit includes, what I hand off, and how I price it.
How long does a proper recaulk take?
I allocate about 90 minutes per tub or shower for a thorough recaulk: removal of old caulk, full prep, tape, silicone application, tooling, tape pull, and cleanup. That includes the caulk for the tub-to-floor joint, the tub-to-tile joints on three sides, and around any fixtures or trim plates. The 24-hour cure window means the bathroom is usable for everything except a shower until the next morning.
I recaulk tubs and showers across the Fraser Valley. See home repairs in Langley or home repairs in Surrey for how I handle a bathroom list in each town. If a grab bar is going into a fibreglass surround on the same visit, grab bars in a fibreglass shower explains how it gets mounted.
