How to Seal a Bath Properly

how to seal a bath

Bath sealant can make or break a bathtub. When it's in its prime, it can be gleaming, glossy, and glorious. But at its worst, it can be unsightly, worn, and completely mould-ridden. If you're ready to tackle that aging sealant around your bath, or you're upgrading a new bathroom suite; fear not, we've got you covered. 

In this blog, we've created a careful step-by-step guide on how to apply bathroom sealant, with useful tips along the way for each valuable part of the process.

Read on to find out just how easy it can be to seal a bath, whether you’re a professional or looking to save money with some DIY...

Why should I seal a bath?

Ceramica Double Ended Curved Bath With Side Panel

Sealant for a bath is a simple way to freshen up a tired bathroom, especially if your current sealant is looking a little worse for wear. Not only that, bathroom silicone sealant will protect your bath from leaks, giving it a sleek and smooth finish, along with preventing any water from getting underneath the tub, which can lead to unwanted mould!

As baths contain large volumes of water (because let's face it, the fuller the better!), they are often prone to accidentally overflowing and other occasional wear-and-tear leakages. If this water gets down the side and underneath the tub, it can then collect on the floor which leads to flooding, rotting, and eventually, a build-up of mould. This can eventually bring along a whole host of issues including health risks and repair costs (learn more on the health risks here).

Another reason to seal or reseal a bath is to give your bathroom a quick spruce-up. Tired-looking sealant can drag the visual appeal of a bathroom right down, so a smooth sealant is a simple bathroom refresh without breaking the bank!

Read more: How to Remove Bathroom Mould

What to seal a bath with

pink gloves cleaning a bath

To seal a bath with silicone sealant, which is arguably the most common method, we suggest getting everything you need ready before you begin. Here's our list of everything we think you’ll need to aid you on your sealing journey:

  • Safety gloves
  • Safety glasses
  • Masking tape
  • Safety knife
  • Caulking gun
  • Silicone sealant
  • Silicone applicator (or a round-headed tool)

In our step-by-step guide, we will be showing you how to use silicone sealant, but there is an alternative method that you can try (which will require different equipment). Flexible caulking strips can also be used. A flexible caulking strip is a self-adhesive that can be cut to fit the gap between your bath and the wall, giving the same beneficial impact as a sealant.

How to seal around a bath - step-by-step

ceramica curved straight bath tub

Once you’ve got your equipment and tools ready, it’s time to start sealing your bath (which we recommend leaving a whole afternoon to do!).

For our step-by-step guide, we will be using a straight bath as a demonstration (a single or double-ended bath will have the same results), but this process can also apply to corner baths and whirlpool baths, too!

Step one: tape the edges

Use tape as a guide for your sealant

The first step is to use your masking tape and place it around the edge of your bath, marking where you're going to put your silicone.

Work from the back corner of your bath (the corner furthest from your bathroom door) and keep the tape at least 3mm from the wall. This will ensure a neat finish to the silicone.

Step two: preparing the sealant

A caulking gun makes applying sealant easier

Wearing your safety gear from this point on, use your knife to cut the silicone open. Before attaching the head or nozzle of the silicone, cut the tip as close to a 45-degree angle as possible, this will make applying it much easier. Then, simply place the silicone into the caulking gun ready for application (if you've reached this point and are unsure what a caulking gun is, it simply acts as a pump for squeezing the silicone out of its tube).

Step three: apply the sealant

Get as close as possible to the edge of the bath that you want to seal, and then apply the silicone by pressing the caulking gun trigger. In a smooth movement and a steady hand, begin with the furthest corner, as you previously did with the tape. We recommend working in the direction of the image above, This will make sure you don’t touch any new silicone you’ve put down. For example, if your tub is surrounded by three walls, start at the ‘top’ and go in a C-motion. If possible, apply silicone to both the base and the wall.

Top tip: Fill the bath when you apply the sealant, the weight of the water will ensure the sealant won’t crack when the bath is used later. This gives a real representation compared to an empty bath.

Step four: smooth the sealant

Smoothing sealant with an applicator

Using a sealant applicator, a wet round-ended tool such as a wooden spoon or even a wet fingertip, smooth and shape the sealant edge at an angle. This will help the sealant to shed water back into the bath, particularly if it is a shower bath.

This is an important step because it ensures no dirt, germs or even mould can get in behind the sealant. Sealant can take up to 24 hours to set, so make sure your bathroom (or the bath at least) is off-limits for that time!

Once your sealant has set, then you're free to sit back and enjoy your newly sealed bath!

How to seal a bath with a large gap

A large gap to the wall can result in large costs

If you've read through our guide and realised with horror that there is a large gap between your bathtub and the wall, preventing you from sealing around your bathtub, don't panic! This issue can be easily remedied. We suggest removing any silicone or grout that is already there and 're-seating' (moving) the bath closer to the wall. This will then allow you to seal the bathtub as you normally would using our step-by-step guide above.

If you can’t or don’t want to re-seat the bath, there are two alternative options. The first is to plug the gap with an adhesive and bonding material. Once this has dried, you can then seal the bath using the above process. The second choice is to use flexible caulking strips. This is a self-adhesive tape that you cut using a safety knife to fit the length and gap required. Once cut, simply peel off the backing, press the strip into place and you're done!

How do I remove sealant?

Bath sealant with mould

If you've been plagued with unsightly sealant, we feel your pain. Discoloured and mouldy sealant can be a burden on any bathroom. If you're looking to remove sealant that is worn, tired-looking or covered in mould, the quickest and best solution is to cut it and use a flat-headed screwdriver to lift it away.

Using a safety knife, gently cut the old sealant and scrape it away with a screwdriver until you have removed as much as possible. Use your finger to rub the remaining strands off or use white spirit/turpentine. Next, use an old cloth and rub it over the strands to remove the rest.

Top tip: caution is advised when proceeding with this step, as it can be easy to accidentally scratch or damage the surface of your wall or tiles.

As you follow these steps, you should find sealing and resealing your bath a straightforward job that isn’t too time-consuming. So once you have learned how to seal a bath, you're well on your way to learning other bathroom DIY tasks, such as fitting a tap, a basin, or even tiling! The world (or at least, your bathroom) is your oyster.

But for now you can sit back, relax, and enjoy your freshly sealed bathtub...

relaxing candlelit bath tub with book and drink

If you're looking for further bathroom DIY advice and inspiration, you may find the following posts useful - How to Replace a Toilet Seat - How to Fit a Bath Panel - DIY Home Improvements.


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