What's the difference between epoxy and cement grout?
Grout fills the joints between tiles; it is not the flexible sealant used at corners and movement joints. Cement grout is made from cement, fillers and pigments. It is familiar to install and usually has a lower material cost, but its pores can take in moisture and dirt. Epoxy grout combines epoxy resins and fillers. Once cured, it forms a dense, non-porous joint that is highly resistant to water, staining and mould.
| Feature | Epoxy grout | Cement grout |
|---|---|---|
| Water resistance | Non-porous and highly resistant to water | Porous and can absorb moisture |
| Mould and staining | Highly resistant to staining and mould growth on the grout surface | More likely to hold moisture, staining and surface mould |
| Needs sealing? | No | Often sealed to help reduce absorption |
| Colour stability | Generally retains its colour well | Can discolour or become patchy over time |
| Installation difficulty | More demanding to mix, apply and clean | Generally easier to apply and clean |
| Cost to install | Higher material and labour cost | Usually lower material and labour cost |
| Best use | Showers, balconies and other demanding wet areas | Lower-wet-use tiled areas where it is suitable and maintained |
The better choice depends on the location and the tiled surface. Shower and exposed balcony joints face regular water exposure, so a dense grout is useful. Flexible silicone is still needed where tiled surfaces meet, because those junctions move differently from the tile field.
Why cement grout fails in showers
Cement grout does not necessarily fail because it was installed incorrectly. Its porous nature means repeated shower water, soap residue and cleaning products can gradually affect the joint. When grout becomes worn, cracked, missing or difficult to clean, water can pass through the tile joints. Dark staining and mould can become harder to remove when contamination sits within the pores rather than only on the surface.
Corners, wall-to-floor junctions, around taps and along the shower screen need flexible silicone, not rigid grout, because building movement can crack a hard joint. Replacing grout alone will not correct failed silicone, loose tiles, plumbing leaks or problems below the tiled surface.
Is epoxy grout waterproof?
Epoxy grout itself is waterproof once cured. It helps stop water entering through grout joints, and its non-porous surface does not need a topical sealer. That does not make the complete shower system waterproof. The waterproof membrane sits behind or beneath the tiles, while silicone protects movement joints and penetrations such as around fittings.
If the membrane has failed, the floor has a drainage problem, tiles are broadly loose, or water is coming from plumbing, epoxy regrouting is not a replacement for the needed repair. A shower should be assessed on its symptoms and condition, rather than assuming all water damage comes from the grout.
How long does epoxy grout last?
Epoxy grout is far more durable than cement grout and, when cared for properly, lasts many years. Its performance depends on preparation, installation, movement of the tiled surface, cleaning practices and other shower faults. Keep an eye on silicone and changes in the tiles, because they serve different roles from grout.
10-Year Warranty on eligible epoxy re-grouting work, subject to terms
Does epoxy grout cost more?
Yes. Epoxy grout costs more to supply and takes more skill and labour to apply than cement grout. It has a limited working time, needs careful cleaning during installation and is less forgiving of shortcuts. A regrouting quote also reflects tile size, joint length, access, old grout condition and whether silicone or other repairs are required. Small mosaic tiles, for example, have far more joint line than large-format tiles.
The upfront cost should be weighed against the intended use of the room. For a regularly used shower or tiled balcony, choosing a grout that resists water and staining can reduce the need for frequent grout sealing and cosmetic touch-ups. See the related shower regrouting costs page for current pricing information.
Can you put epoxy over old cement grout?
No. Epoxy grout should not be spread over old cement grout as a cover-up. A thin layer over an aged or contaminated joint may not bond properly, and it leaves the deteriorated material underneath. The existing grout needs to be removed to the appropriate depth, the joints cleaned and dried as required, and then filled with epoxy grout.
Preparation is an important part of regrouting work. It also gives the installer a clearer view of cracked joints, damaged tiles and failed silicone. If tiles are loose, the substrate is compromised or a plumbing issue is suspected, that needs to be addressed rather than masked with new grout.
How to care for epoxy grout
Regular, gentle cleaning is usually enough. Use a pH-neutral cleaner suitable for tiled surfaces, rinse product residue and use a soft brush or non-abrasive cloth for stubborn marks. Good ventilation and wiping excess water after showering can also reduce soap build-up.
- Use pH-neutral cleaners and follow the product directions.
- Use a soft brush or non-abrasive cloth rather than scouring pads.
- Avoid bleach, acids and abrasive cleaners, which can affect surrounding surfaces and silicone.
- Do not use pressure washing in a shower or on tiled joints.
- Check silicone at corners, the shower screen and fittings, and arrange replacement if it cracks, lifts or separates.
Cleaning cannot repair structural movement, loose tiles or a failed membrane. If grout is cracking again, tiles sound hollow or there are signs of moisture outside the shower, arrange an assessment rather than relying on cleaning products or a surface coating.
Frequently asked questions
Is epoxy grout better than cement grout for a shower?
For a shower, epoxy grout is usually the more suitable option because it is non-porous and highly resistant to water, staining and mould. Cement grout is less expensive and easier to install, but its porous surface can absorb moisture and become harder to keep clean in a wet area. Silicone is still required at movement joints.
Does epoxy grout stop a leaking shower?
It can help where water is entering through failed grout joints, together with replacement silicone where needed. Epoxy grout itself is waterproof, but it does not replace the waterproof membrane behind the tiles or repair a plumbing leak, loose tiles or drainage faults. The cause of the leak needs to be identified first.
Does epoxy grout need sealing?
No. Properly cured epoxy grout is non-porous and does not need a topical grout sealer. This is different from cement grout, which is porous and may be sealed to reduce absorption. Sealant and grout are different products: silicone still needs to protect corners and other movement joints.
Can epoxy grout be applied over existing grout?
No. Applying epoxy over old cement grout is not a sound regrouting method. The old grout should be removed, the joints prepared and cleaned, and new epoxy grout installed in the joint. This avoids leaving cracked, contaminated or deteriorated grout beneath a thin surface layer.
Why is epoxy regrouting more expensive?
Epoxy material costs more and is more demanding to apply and clean than cement grout. The overall quote also depends on the size and layout of the shower, tile size, the amount and condition of old grout, and whether silicone replacement or other work is required.
Can I clean mould from epoxy grout?
Surface marks and residue can generally be cleaned with a pH-neutral cleaner and a soft brush. Avoid bleach, acids and abrasive products. If staining keeps returning, grout is cracked, silicone is failing or there are signs of moisture beyond the shower, cleaning alone may not address the underlying issue.
Send photos for a fixed quote
Send a photo of the whole shower or balcony and a close-up of the grout. We assess the visible condition and explain whether regrouting and resealing are suitable.