Top Tips For Tackling Common Sealant Problems In Bathrooms

When installing bathroom fixtures such as shower units, sinks, bath tubs and so on, it’s essential to apply sealant around the joins to prevent moisture seepage and to stop dust and debris from building up around the unit. It can also help to hold components in place, fill gaps and hide the join between different surfaces. 

Silicone sealant is durable and flexible, and it can be clear or white depending on the look you want to achieve. For example, if you are joining dark granite tiles to a glass shower screen, then clear silicone sealant will be unobtrusive. However, if you are joining white tiles to a white shower tray or other white surface, then it makes sense to use white sealant.

Unfortunately, sealant in highly humid environments such as bathrooms can be prone to a range of problems, particularly as it ages. Here are some common issues with bathroom sealant and how to tackle them. 

Mould and mildew growth

One of the most common problems found with bathroom sealant is mould and mildew growth. Sealant, particularly around shower units, is constantly exposed to moisture and the warm conditions of a shower cubicle can provide the perfect conditions for mould growth. 

This not only looks unsightly, but can also be a health hazard. Mould spores can trigger or aggravate allergies such as eczema and asthma, and can be dangerous for those with compromised immune systems, the old and frail or the very young. The effectiveness of the sealant may also be compromised, causing seepage into walls and flooring. 

Mould that has not deeply penetrated the surface of the sealant can be scrubbed off with an old toothbrush and a mixture of water and distilled vinegar, or a commercial mould remover. If this doesn’t work, it may be necessary to replace the sealant. Use a sharp utility knife or sealant removal tool to take out the old sealant.

Wear gloves and a face mask for protection, and apply mould killer to clean the area before applying new sealant. Wipe away the residue of the cleaner first and ensure that the area is dry and clean. Use a fresh mould-resistant sealant using a cartridge gun, applying a consistent pressure and keeping your hand steady.

Use an applicator tool or your finger to smooth out the surface of the sealant bead so it will dry in a neat even line. You may wish to use masking tape to create a neat outer edge to the sealant, particularly if you are using white sealant against a contrasting colour. For very strong colour contrasts, consider using a clear sealant. 

To prevent the problem recurring, ensure that your bathroom is well ventilated and wipe down your shower enclosure with a towel after use.

Shrunken sealant

Over time, sealant may shrink and no longer adequately fill gaps or provide a moisture barrier. If the sealant has shrunk significantly, it may be possible to apply new sealant directly over it rather than attempting to to remove it. 

Use a flexible sealant that is specifically designed for bathrooms and can cope with moisture exposure and accommodate movement in fixtures such as shower trays, which may move slightly with the weight of a person stepping on them. Control the humidity levels in the bathroom with a fan or open the windows often. 

Cracked, peeling or loose sealant

Age, poor quality product, or improper application can cause sealant to crack, peel, or fail to adhere properly. This can potentially lead to water damage in your bathroom as the sealant is no longer able to prevent leaks. The only solution in this case is to remove the old sealant and re apply fresh, as previously described. 

Choose a good quality product that is flexible and specifically designed for use in bathrooms. Allow it to cure according to the manufacturer's instructions before using the bathroom fixture. 

Discoloured sealant

White sealant can take on a yellow or brownish colour over time, due to contact with soap and cleaning products. Clean the sealant regularly to avoid residue buildup, but take care with harsh chemical cleaners that may cause further discoloration. If cleaning has no effect, it may be necessary to replace the sealant with a stain-resistant product.