Knowledge Centre
Grout & Epoxy
Learn all you need to know about grout & epoxy here.
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The basics...
What types of grout are there?
Grout generally falls into two camps, either cement-based or epoxy.
Most modern cement grouts are flexible to allow for movement within the subfloor or walls but remain structurally strong enough to fill grout joints from 2mm to 20mm - and are also antibacterial! However, there are cementitious grouts that are designed specifically for narrow or wide grout joints or specific tile materials - for this reason, you should check the packaging.
Epoxy will do all of the above and has the added characteristics of being waterproof, chemical resistant and sterile, but it does cost significantly more. Epoxy is more difficult to apply and requires the mixing of two chemical components to create the epoxy. It should be applied by a professional unless the user has experience or is very confident in its use.
What are the benefits of Epoxy grout?
Epoxy grout has several benefits over and above the cementitious grouts, namely: increased strength and abrasion resistance, chemical resistance, and is waterproof. These traits make it ideal for sterile areas as it does not absorb liquids or allow bacteria growth and has a high degree of flexibility. As it is inert, it does not give off or leach any chemicals that could prove harmful to the environment or the end-user/customer.
Is Epoxy grout harder to work with?
Epoxy has two components that are mixed to form a resin. This grout should be applied by a professional unless the user has experience or is very confident in its use. It is harder to use and more time-consuming to apply than a cementitious grout, but a professional tiler will be able to apply it and the long-term benefits will certainly outweigh the short-term increased costs and time involved.
How much extra does Epoxy grout cost?
Epoxy grout typically costs an approximate £15.00 per m2 more than cement-based grout. This includes the increased cost of the product itself, sponges/ emulsifying pads and the extra labour that is required to achieve the perfect finish.
For a more in-depth explanation, please see below.
Is grout antibacterial?
Always check the label! Many grouts are antibacterial and have a resistance to the growth of bacteria and mould; however, some antibacterial products contain chemicals that, while regulated in other industries (e.g farming), are not in the construction industry, and are considered potential carcinogens due to their ability for particles to become airborne. Over time, non-antibacterial cement-based grout will become less effective as the pH value of the grout lowers due to salinification and as the lower pH values are less resistant to bacteria growth. For this reason, the manufacturers use either a pesticide, fungicide or a natural product to ensure the antibacterial properties remain active throughout the life of the grout. We choose to use Kerakoll grouts (other makes are available) due to their eco-friendly, safe-to-use nature and ensure the end-users safety. Kerakoll creates their own products to help realise their values, innovating in many areas to keep workers and occupants safe during and after construction with alternative formulas and compounds in their products. If you wish to learn more about antibacterial grout or how Kerakoll has achieved this please read our blog here.
Is grout mould resistant?
Generally, most modern-day grouts are mould resistant (please check the packaging) and the manufacturers achieve this resistance in different ways. Some use pesticides or fungicides which can be harmful to humans and some use natural methods such as lime to make the grout permanently resistant to mould and bacteria.
Please see our blog on antibacterial grout for more information here.
Is grout flexible?
Most modern-day grouts are flexible and many manufacturers also produce a flexible liquid additive to further enhance the flexibility and abrasion resistance of the grout. Although the grouts are flexible and will cope with underfloor heating and slight movement, they will not cope with unstable backgrounds where the movement is more than slight. These backgrounds need to be addressed prior to the tiles being laid.
Why would I use an admixture with my grout?
Use of an admixture in the grout improves the grout’s flexibility, imperviousness, bonding ability and its abrasion resistance. The extra flexibility is the main reason an admix is used and can help with substrates that are prone to limited movement. Although most modern grout is now flexible enough to allow for this, an additive would enhance this characteristic within the grout.
Are grouts UV resistant?
UV light can bleach colours depending on the polymers and pigments used. Some grouts have very good UV protection and are ideal candidates for external areas or areas subject to strong UV light.
Check with your supplier if this is an important requirement.
Our range of grouts do have excellent UV resistance as do other ranges that are available.
Can I use grout as an adhesive?
Yes, you can use epoxy grout as an adhesive, aside from its bond strength and resistance to many chemicals, it is an ideal choice for coloured glass mosaics. As the colour of the adhesive matches the colour of the grout, it is ideal for glass mosaics where the adhesive may be visible from the front due to the transparency of the glass; i.e a blue glass mosaic with blue adhesive and grout will give a truly uniform finish.