By Kerry Hale

Bathroom Sealing Guide: How to Seal Baths, Shower Trays and Sinks

  • Thursday 29 August 2024
  • 4 minute read

The silicone seal around baths, shower trays, and bathroom sinks needs replacing over time, especially when unappealing black spots ruin the look of your bathroom or the sealant loses its adhesion. Old or damaged bathroom sealant can let water seepinto cracks and cause leaks, mould and rotting.

This guide explains why some parts of your bathroom need to be sealed, how to do it yourself and some common mistakes to avoid.

Where do you seal in a bathroom?

Resealing your bath, sink, countertops, shower tray, and enclosure helps keep your bathroom looking great and prevents future water damage.

Silicone sealing is easy to do yourself when you know how. This guide includes step- by-step instructions.

Bath

The joint between the bath and the wall needs proper sealing to avoid water getting beneath the tub, which can lead to rust and mould.

Shower

The edges of shower trays or enclosures should be sealed where the tray or screen meets the wall or tiles.

Sink

Seal the joint between the sink and the countertop or wall to avoid water leaking into gaps or cracks.

Countertop

Seal around bathroom countertops properly to create a watertight barrier and avoid mould and rot.

What you'll need:

Sealant remover

  • Knife
  • Cleaning sponge
  • Liquid soap
  • Masking tape
  • Silicone sealant
  • Sealant gun
  • Cloth

 

It’s important to use silicone sealant instead of normal grout to seal bathroom fixtures. Grout isn’t suitable for sealing around baths, sinks or shower trays.

How to seal a bathroom

Our step-by-step instructions will help you reseal your bath, shower tray, sink or bathroom countertop.

Step 1: Remove the old sealant and clean the surface

Remove the old sealant using a knife or a specialist sealant remover. Cut along the top and bottom of the seal, taking care not to scratch the surface, then pull the sealant out and scrape away any residue.

 

The area may have residue, so use warm, soapy water to clean it and let it dry before you start to reseal.

Step 2: Tape off the edges

Place masking tape above and below the joint you plan to seal. Stick one length of tape along the shower tray, bath, sink or countertop (around 3mm from the wall) and another along the wall (around 3mm above the surface).

 

Taping should leave just the joint exposed and ready for sealant.

Step 3: Apply a small amount of sealant

Use a narrow nozzle to apply a small amount of sealant along the joint. Run your finger along the soft sealant to press it right into the crack, ensuring it’s completely covered and airtight with no gaps.

Step 4: Cut the nozzle wider and apply more sealant

Use a sharp knife to cut the nozzle about 2cm down at a 45-degree angle. The wider nozzle lets you apply a thicker layer of sealant to fill the gap between the lengths of tape.

 

Reseal the areas you’ve already sealed with a small amount, applying a second layer all the way around.

Step 5: Wipe away the excess and remove the tape

Wet your finger and run it along the sealant to ensure it’s perfectly smooth without any bumps or gaps.

Mistakes to avoid when sealing a bathroom

Proper sealing helps keep your bathroom looking and working at its best. These common mistakes can compromise the quality of your job.

Not cleaning the area

Sealant adheres best to clean, dry surfaces, so make sure you thoroughly clean the bath, shower tray, sink or countertop and the adjoining wall before applying the silicone.

Using a poor-quality sealant

Avoid poor-quality sealants that may not adhere properly. Only buy sealants from reputable suppliers and brands you trust.

Rushing the drying process

Wait for your new sealant to be completely dry before using the shower or bath. Getting sealant wet before it’s had time to dry can spoil its perfect finish.

Not smoothing the seal

Use your finger to smooth around fresh sealant as soon as it’s applied, ensuring a flat surface with no bumps or gaps.

Sealing electric showers

Don’t try to seal around an electric shower by yourself – they should always be installed by a professional and often don’t need to be sealed.

 

You can keep exploring our guides for more helpful bathroom installation advice or find design inspiration and choose the Mira products for you.

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