Richard Morgan/DIY Works
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Bathroom sealants provide a defence against water penetration in areas prone to high humidity or moisture, making them suitable for applications such as showers, baths and many other applications. Whether you are reapplying a sealant or installing new bathroom fittings, a water-tight seal is crucial to prevent water damage.
Areas that often require sealing in the bathroom to ensure a watertight fit include the tiles, shower trays, cubical doors, bath and sanitary fittings. Although there is a range of sealants that you could use, it’s crucial that you use a formula that’s water-resistant and includes fungicides to prevent the build-up of mould, mildew and other bacteria.
To help you choose the best sealant for your bathroom, our hand-picked selection features top-performing formulas chosen through our first-hand experience sealing various fittings, testing and thorough research.
Best Overall: UniBond Anti-Mould Silicone Sealant
Best Value: Everflex 500 Bath & Sanitary Silicone
Best All-Rounder: Dow Corning Dowsil Bathroom Sealant
Best Anti-Mould: Everbuild Forever Clear Sealant
Best Quality Finish: Gorilla Glue Mould Resistant Sealant
Best For Small Jobs: 151 Bathroom Silicone Sealant
How The DIY Works Team Tests & Rates The Bathroom Sealants
As we own several properties (rentals and Airbnb’s), we are often replacing damaged sealant or sealing new fittings in the bathroom.
As shown in the photo below, we recently sealed a bath but we’ve also used sealants for showers, toilets, tiling, window frames, kitchen surfaces and so much more. Over the years, we’ve also tried and tested a whole range of sealants from some of the most reputable brands in the UK and there is certainly plenty to choose from.
Richard Morgan/DIY Works
During our ongoing testing of bathroom sealants, we analyse their ease of application, quality and formulation (i.e. mould resistance).
To display more of our experience with various bathroom sealants, we filmed and posted a video on our YouTube channel that shows us testing a bathroom sealant whilst demonstrating how to seal a bath.
To keep up our commitment to reviewing and testing the latest bathroom sealants (for this article), we are continually testing out the latest offerings from top brands in the UK. This means that when we notice a brand has released a new and improved formula, we will attempt to buy it and put it to the test (where applicable).
As well as our experience and testing of multiple sealants, we also based our recommendations on the latest research and several factors. Some of the factors that we took into consideration included the formulation, ease of application, colours and tube sizes available, drying time, ability to resist mould, awarded certifications, compatible surfaces, bulk buy options and value for money.
Bathroom Sealant Buying Guide
A bathroom sealant not only makes fittings such as showers or baths waterproof but it also provides the finishing touch. To help you make an informed buying decision, we have produced the below guide regarding bathroom sealants.
Caulk vs Silicone
Caulk is a popular method of sealing walls, ceilings and pieces of trim and it can also be painted over, which makes it easier to blend in with the rest of the room. However, it’s not the best option for bathrooms because it’s not completely water resistant.
A silicone sealant on the other hand is the better choice for a bathroom because it provides a waterproof barrier against moisture. However, due to the moisture-repelling property of silicone, it means that it can’t be painted over.
Therefore, you’ll want to use bathroom paint elsewhere in the room and seal the areas around the bath, sink, shower and anywhere else with the sealant.
The majority of bathroom sealants require 24 hours to completely dry but there are many fast drying formulas available. For example, the UniBond sealant is touch dry in just 1 hour, which allows you to get on with other tasks.
Most manufacturers provide a range of different colours to match your bathroom’s décor. The most common include clear, white, ivory and grey because they suit the majority of bathrooms. However, if you need to paint over the sealant, you may be able to do this using an oil-based primer that can then be painted over.
How To Use a Silicone Sealant
Application of a bathroom sealant isn’t as simple as spreading it on the surface and allowing it to dry. This is because the surface needs to be fully prepared and the gun needs to be loaded with the sealant before you can begin. Below is a brief guide to the steps required to seal surfaces within your bathroom.
Before you begin, the surface must be well-prepared and completely dry. The best option would be to completely remove the old sealant, which will strip back all the grease and dirt. Once removed, you can clean the surface that’s to be sealed and allow it to dry out.
If you are worried that the surface isn’t completely clean, you can use a gel remover or even white spirit upon a damp cloth to wipe the surface.
2. Attaching to the Sealant Gun
If you are using a tube that requires a sealant gun for the application, you’ll need to correctly attach it. To do this, we recommend the following steps:
- Release the plunger by pressing the release at the back of the gun.
- Put the tube into the gun and push the plunger to the back.
- Cut the tip and push a nail through the hole to pierce the inner seal.
- Place the gun at a 45-degree angle along the joint width you want to seal.
Once the surface has been prepared and the tube is loaded within the gun, you are ready to begin sealing. You’ll want to start in a corner and work across the length of the surface in a smooth movement.
If you are planning to seal a bath, we advise that you half-fill it to prevent any movement once it has dried. After the sealant has completely dried, you can then empty the bath.
To prevent mould and mildew, you’ll have to regularly clean the sealant. Soap and other residues can instigate bacteria growth upon the sealant but catching it before it begins to spread is highly advised. However, if you do notice the growth of mould, you can use one of the many mould removers available to quickly eliminate it from the surface.
Adding the finishing touch to your bathroom with a quality sealant is highly recommended. Without using a sealant, you’ll leave areas exposed to moisture, which can then lead to water damage and bacteria growth.
All of the recommendations listed above are developed by reputable brands and are suitable for a range of budgets. They also include sealants that can be applied by a gun or squeeze tube to best suit your requirements. However, if you need further information with regards to bathroom sealants, feel free to get in touch and we’ll try to provide our assistance where possible.