Waterproofing a Bathroom with a Sealant

Making sure that the bathroom does its job of controlling water spillages and leaks is of fundamental importance to a property. Leaks that are allowed to seep through cracks and gaps can cause serious damage to the structure of the entire building. When renovating a bathroom, it is always a good idea to strip the floor down and apply a new coat of waterproofing sealant. This article looks at how to waterproof a bathroom using such a sealant.

Tools & Preparation

Measure the floor area of your bathroom, and purchase enough waterproof sealant to cover the whole area. You will also need a mixing paddle, and brush to apply the sealant and a suitable container to mix the sealant in. In the bathroom itself, you should ensure that the floor is completely clear of any traces of tiles, mortar and cement. Grind or sand any rough patches, and fill any holes you see with a simple patch mix.

Mix the Sealant

Empty the contents into a large container, such as a basin, and stir slowly. At this stage, you can use a power assisted mixer (pneumatic or electric will suffice) to start the mixture off. You are looking to build the mix up into a smooth flowing liquid. Once the liquid has become a little more free flowing, switch from the power assisted mixer to the hand paddle. Continue to mix until the contents become smooth and flowing.

Pour the Mixture

Transfer some of the sealant to a smaller container, such as a bucket, and begin by pouring the sealant into the area desired. Then, use the application brush to even the sealant out; aim for a coating of the sealant that is around  one and a half millimeters thick. Continue to transfer the sealant from the large container to the smaller container, and pour and smooth until the whole floor area is covered.


In many cases, more than one coat of waterproofing sealant should be applied. The second coat must only be applied when the first coat has fully dried. This is important. Don't be tempted to hurry the job and apply the second coat too early. Doing this will prevent the sealant from forming a full and complete bond, and it won't take long for water to penetrate through this weak area. Apply a second coat, in the same way as the first, once the sealant is fully dry.

Install Flooring

Once the second layer is fully dry, you are free to lay the flooring on top. Wood, concrete and tiles can all be laid on top of the sealant. To speed up the drying process, keep a window open in the bathroom after you have applied each coat of sealant. For more tips and suggestions, contact local experts such as Westside Sealants Pty Ltd.