Knowledge Centre
Grout & Epoxy
Learn all you need to know about grout & epoxy here.
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Waterproof or Water-resistant?
Is grout waterproof?
It depends on the grout used but broadly speaking, the answer would be no.
Most common grouts are cement-based (cementitious), being porous in nature (this includes allowing the passage of water through them). Cementitious grout can stain and change colour when wet but does not break down when exposed to water. When using cementitious grout, it is wise to waterproof your walls by using a waterproof solution and tape called tanking.
Epoxy grout, however, is totally impervious to water and therefore waterproof. It is also chemically resistant, resistant to stains and retains the same shade of colour whether wet or dry due to the fact it’s impermeable. It is the perfect choice for many situations including food prep areas and operating theatres, as well as domestic situations.
Epoxy should be applied by a professional unless the user has experience or is very confident in its use!
If it is not waterproof, why is cementitious grout suitable for swimming pools?
Cement-based grouts are water-resistant not waterproof. This means it will not break down when subjected to immersion and will remain unaffected by constant submersion.
Why doesn’t the swimming pool leak if the grout is not waterproof?
The structure of the swimming pool must hold water in its own right, therefore it is tanked (waterproofed) before tiling and tested to ensure, once filled, the water level does not drop beyond the expected allowance. The tiling is applied as a decorative veneer and is not a factor in making the pool waterproof.
Isn’t water-resistant and waterproof the same?
No, water-resistant and waterproof are not the same and this is where a great deal of confusion arises. In simple terms, waterproof grout, such as epoxy, repels water and is impervious to it meaning it is waterproof. Whereas a cement-based grout, although will not be worn down or damaged by constant wetting, does not repel water and instead absorbs it; therefore it is water-resistant but not waterproof.