Waterproof Grout sealer – A complete guide to application and maintenance

In this article, we are talking about sealing and waterproofing the grout in between your tiles. The grout is the cement-like liquid you fill between the gaps of your tiles. Often people think the grout is waterproof, however, it is usually quite coarse and porous. Water, oil and other liquids can penetrate it quite easily. This means your grout, if not sealed, can stain, grow mould and start to smell if not properly maintained and looked after.

grout sealer for bathroom floor

If you’d like to keep your grout from being impregnated and ultimately lasts longer it is a good idea to seal and waterproof them. If you use a good sealant, this has to only be done once. 

Types of sealer

Silicone sealer

This is generally used in bathrooms and toilets on edges but can be used for both indoors and outdoors. It is a flexible material so it can be easily applied. 

However, silicone sealers protect against water and water only. Silicone sealers have the same size molecules and the large molecules can only fill up a certain type of space in the grout. If you spill juice, grease, wine etc. These types of liquids can eventually penetrate pass the silicone. 

In our opinion, a silicone sealer shouldn’t really be used anywhere but edges of a shower perhaps (even then we would recommend a water-based sealer). 

Water-based Sealer

Water-based fluorochemical sealers are much better. They are usually more expensive but it does a much better job. It renders the surface of the grout hydrophobic and thus water or any other liquid doesn’t penetrate and can be easily wiped off. 

This also allows any water vapour to pass through the grout from underneath allowing it to be breathable. Any damp from underneath the tile can dry over time.

How it works 

The diagram below gives you an idea of how these two sealers differ. One has a number of different molecules sizes and blocks liquids of varying molecules whereas the silicone is one molecule size and thus molecules of other sizes can pass through. 

Example and diagram

water proof grout sealer
GoProtect Grout Sealer

Now there are of course very good ones on the market, we are going to be using our sealer for this project as we believe it is one of the best grout sealers on the market. GoProtect grout sealer is a water-based, odourless sealer that is fast-acting and lasts for a while. 

What you need

  • J-cloth if over … tiles (not essential)

How to use

This is extremely easy to apply. Just by going all around the perimeter of the tiles, it really is as simple as spraying the grout sealer on and leaving it there. Make sure you are around 10cm away. Seal again within 2 hours of the first. 

Wipe off any excess sealant from the tile, however, this is not necessary as this acts as a sealant for any porous material and can be used as a natural stone, brick or terracotta sealer.


There are many great sealers out there on the market. Of course, we have used our one and we do recommend using a water-based sealer. They are more expensive however do a far better job. 

If you’d like more information on this or would like to speak to one of us, feel free to get in contact. 

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