How to Recaulk a Shower or Bathtub

What You'll Need
Wet sponge
Commercial caulk
Caulk remover
Rubbing alcohol
Commercial bleach
Blow-dryer or hair-dryer
Masking tape
Caulking gun
Utility knife

You don’t need professional help to recaulk your showers or bathtubs. Caulking is easy and forms the core activity of most bathroom-based repairs. Recaulking can be easily done by using some basic supplies and the information provided below.

Shower and Bathtub Caulking Basics

The joints where the shower or bathtubs make contact with the bathroom walls are susceptible to moisture seepage. Caulking is effective and protects the outer lining of tubs and showers against moisture. Loose or missing caulk can also damage the bathroom walls, particularly the tiles. However, the caulking seam is often eroded and needs to be strengthened periodically. This is when re-caulking the shower or bathtub becomes necessary.


Step 1: Choosing Your Caulk

You should choose caulk that is best suited for bathroom repairs. For starters, choose caulk sold in the form of bigger, caulking tubes. Bathroom caulking seams are much wider and the bigger tip of larger caulking tubes is ideal for sealing them. The caulk should be a silicone-based caulk if your bathtub or shower has fiberglass elements. No other commercial caulk can form better bonds with the fiberglass surface than silicone caulks. Further, this is one of the most water-resistant varieties of caulks. You can also consider caulks containing polyvinyl acetate if mildew is a serious issue in your bathroom. Polyvinyl caulks are reputed to have negligible fungal susceptibility.

Step 2: Preparing Surfaces for Re-caulking

You need to remove the old caulk seam. The caulk of most showers is easy-to-displace but old bathtubs have a hard-set, thick caulking layer. You can use a blow-dryer/hair-dryer to heat-up such caulk before scraping it. You can use a scraper or a putty knife for peeling-off the old caulk layer. A commercial, caulk remover is also available at hardware supply stores. The idea is to gradually scrape away the old caulk seam without widening the seam’s gapping. After removing the old caulk seam, clean it with rubbing alcohol. This is an antiseptic treatment which kills all the fungal spores or mold growth commonly associated with damp, inner caulking seams. You can also use commercial bleach instead of alcohol. After disinfecting the seam, clean it with a wet sponge. This helps to compress any hard-to-access concrete or caulking debris that haven’t been removed. Allow the prepared caulk site to dry for a few hours before proceeding further.

Step 3: Re-caulking Shower or Bathtub’s Caulking Seam

Using a masking tape, form a marking seam around the tub or the shower’s scraped caulk line. The tape should be laid on the outer periphery of the caulk seam. Insert the caulking tube into the caulking gun. Using a utility knife, slice the tip of the caulking tube. Position the tip into the seam and press upon the caulking gun’s trigger. Stop, once you have laid down a long bead of fresh caulk. Wet your finger and press down upon the fresh caulk, pressing it into the seam. Allow the caulk to dry. You can even leave it overnight for better results. Remove the tape. Using the utility knife, scrape-off any beads of dried caulk hanging from the re-caulked seam.