Replacing a mouldy shower seal with silicone: A step-by-step guide
In the world of home improvement, ensuring the waterproof integrity of your bathroom, shower, sink, and toilet is crucial. Danny Pen, an expert from New Era Plumbing & HVAC, shares his top tips for a professional finish when applying silicone sealant.
- Clean the Surface Thoroughly
Before applying silicone, it's essential to clean the edges and gaps thoroughly. Remove any dirt, old sealant, soap scum, grease, or mildew using an appropriate cleaner. After cleaning, ensure the surfaces are dry to promote strong adhesion and a watertight seal.
- Remove Old or Failing Sealant
If there is existing caulk or silicone that is cracked or peeling, remove it completely with a scraper or sealant remover to ensure the new silicone bonds well.
- Prepare the Gap
For deep or large gaps, insert a foam backing rod (a flexible foam rope) to fill most of the cavity and reduce the amount of silicone needed. This also shapes the sealant bead for durability and flexibility.
- Choose the Right Silicone
Use 100% silicone sealant formulated for bathrooms or wet areas, as these resist mold, mildew, and water better than acrylic alternatives.
- Apply Masking Tape (Optional)
For neat edges, apply painter’s tape on both sides of the joint to create clean lines.
- Apply the Silicone Sealant
Cut the nozzle tip at a 45° angle sized to the gap width. Using a caulking gun, apply steady, even pressure to fill the gap completely without gaps or bubbles.
- Tool the Bead
Immediately smooth and shape the silicone with a caulking tool, a wet finger, or a finishing tool to create a concave, visually neat seal that adheres well and sheds water effectively.
- Remove Tape Immediately
If you used masking tape, remove it before the silicone skins over to avoid pulling cured sealant away.
- Allow Proper Curing Time
Let the sealant fully cure as per manufacturer instructions—typically 24 hours—before exposing it to water to ensure a permanent watertight seal.
For areas that are frequently in contact with water and moisture, Danny Pen recommends using silicone sealant instead of caulk. To smooth out silicone, he suggests using an ice cube and alcohol, as moisture and cold from the ice prevent sticking, and the cube's rounded shape creates a clean and tidy line.
By following these steps, you can achieve a clean, durable, and waterproof silicone seal around showers, sinks, baths, and toilets that is resistant to mold and water damage. Happy sealing!
- To achieve a clean and durable silicone seal in a bathroom, clean the surfaces thoroughly, removing any old sealant, dirt, soap scum, grease, or mildew before applying the new sealant.
- For efficient adhesion and a watertight seal, ensure the surfaces are dry after cleaning.
- For deep or large gaps, insert a foam backing rod to fill most of the cavity, reduce the amount of silicone needed, and shape the sealant bead for durability and flexibility.
- Use silicone sealant formulated for bathrooms or wet areas as they resist mold, mildew, and water better than acrylic alternatives.
- For neat edges and clean lines, apply painter’s tape on both sides of the joint before applying the silicone sealant.
