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How To Seal A Shower Tray

Whether you fitting a new shower tray or resealing your existing tray, our guide on how to seal a shower tray will take you through the job step-by-step.

Once you get the preparations out of the way, sealing a shower tray or bathtub is a fairly simple task that any DIYer can do. Our guide will make sure you have the right tools, products and techniques for a quick and easy job.

Are you about to work on a project that will involve using mortar? If so, you’re in the right place. Mortar is normally used for binding building bricks or blocks to form walls or structures, fill and seal gaps in brickwork, and sometimes to add decorative colour to masonry walls.

If you need to learn how to mix mortar to complete your project, we’re here to help.

Preparing Your Shower Tray

Before you get started, you may need to remove old or damaged sealant from your shower tray. If this is the case, you’ll need to use a utility knife or chisel to cut away as much sealant as possible. You should do so with appropriate safety gloves and be careful not to damage the tray or tiles. Peel away any strands and rub the remaining sealant with white spirit on a cloth.

Once you’ve removed any old sealant, make sure to clean your shower tray and tiles with a cloth soaked in warm water and a mild cleansing agent. Rinse the area with a clean, damp cloth and dry thoroughly. You may want to leave the shower to air dry completely, as moisture will prevent the sealant from properly bonding with the surface.

What You Will Need

  • Bathroom sealant
  • Skeleton sealant gun
  • Masking tape
  • Utility knife

How To Seal A Shower Tray

1. Apply a length of masking tape both on the surface above and the tray below, about 3mm from where you’ll apply the sealant. This will make clean-up much quicker and easier, as well as ensuring you get a neat and tidy line.

2. Particularly if you’ve had problems with the seal in the past, it’s a good idea to apply two layers of sealant to the shower tray. Fit the sealant tube into the skeleton gun and cut off the very tip of the tube. You want this first opening to be small enough to really fit into the gap.

3. Apply an even bead of sealant into the gap, starting from the innermost corner, and move outwards in a steady motion. Then, use a wet finger to smooth the sealant and press it firmly into the gap.

4. Continue immediately with the second layer by cutting the nozzle with your utility knife, about 2cm from the tip at a 45-degree angle. This will help to create a smooth line and flatten the sealant as you apply.

5. Apply the second layer as before and, again, run a wet finger gently along the sealant to ensure the gap is filled.

6. Remove the masking tape while the sealant is still wet and leave to dry for at least 24 hours.

And that’s it! Your shower tray or bathtub is now ready for use. Take a look at our range of showers and plumbing tools to finish the job.

Cement Mixer Method

1. For larger DIY jobs, you may want to consider using a cement mixer. When using a cement mixer ensure it is on a firm, level ground and have someone around to help you with loading and unloading.

2. Using a shovel, load half of the sand, half the water, then half of the mortar cement into the mixer, avoiding build-up of any dry material on the blades of the drum.

3.  Add more water is necessary and mix for 3 to 5 minutes until the mixture is uniform in consistency and colour.

Hand Mixing Method

1. Hand mixing can be hard work, but satisfying if the correct procedure is followed. Always work on a hard, smooth surface, for example a sheet of plywood or in a wheelbarrow.

2. Using a shovel, add half of the sand and half of the mortar cement onto the flat surface or into the wheelbarrow and turn over the sand and cement until they are mixed together well.

3. Form a crater in the middle of the pile and add some water, then bring the dry material to the water and mix until the mixture is uniform in consistency and colour. Add more water to the mixture if necessary.

4. When you’ve finished using the mortar for your project, always clean your tools immediately and leave the area tidy.



How Many Bags Or Tubs Of Blue Circle Mortar Will I Need?
You can calculate the amount of Postcrete you will need by using this handy online calculator.

Where Can I Find More Information About Mortar?
For more information about the Mortar product itself, take a look at this detailed product data sheet.

Where Can I Find More Information Regarding Health & Safety When Using Mortar?
Before using this product, please refer to the product packaging for all health and safety information. You can also take a look at this detailed material safety data download.

Can I Recycle The Packaging?
Yes, all Blue Circle plastic packaging is made of recyclable material so is suitable for recycling and should be disposed of in the correct manner.

We hope you found this guide useful in learning how to mix mortar ready for your building projects. Hopefully you are now feeling confident enough to complete your project to a professional finish. For a video breakdown of the process, you can head to this step-by-step video demonstration.

If you found this post useful, please tag us in any social media posts of your projects using @BradfordsBuild on Facebook, @bradfords_building_supplies on Instagram, or bradfords-building-supplies-ltd on LinkedIn, so that we can see the finished result.

If you need further help or advice, please contact us or visit your local branch to speak to one of our experts.