Epoxy vs Cement Grout: Stain Resistance, Install Difficulty and Cost

Epoxy grout is the better performer: it absorbs almost no water, resists stains and most household chemicals, and never needs sealing. Cement grout is easier to install, more forgiving, cheaper and simpler to repair. Choose epoxy for showers, kitchens and high-stain or commercial areas if you can handle a short working time; choose cement for most other jobs.

How they cure, and why it matters

Cement grout is portland cement, aggregate (sand or fine filler), pigments and often polymers. Mixed with water, the cement hydrates into a hard matrix. Some of the mixing water never reacts and leaves behind a network of tiny capillary pores as it evaporates. Those pores let water, oil and dye in, which is why cement grout stains and why sealers exist. Polymer-modified, high-performance grouts reduce the pore network but can't eliminate it.

Epoxy grout is a resin and a hardener, usually with a separate filler and color component. When combined, they react into a cross-linked plastic with almost no open porosity. There's no water to evaporate, so there are no capillary pores. That one fact explains almost every performance advantage epoxy has, and its cleanup rules too: the reaction starts the moment you mix and continues regardless of conditions, so anything left on the tile face cures there too. For the chemistry behind both, see what grout is made of.

Side-by-side comparison

For a wider grid that includes urethane, premixed and specialty grouts, see the grout type property matrix.

Performance in the real world

Stains and moisture

A dropped glass of red wine or a puddle of cooking oil sits on top of epoxy grout and wipes away. On unsealed cement grout it wicks in within minutes. A good penetrating sealer slows that, but sealers wear and need reapplication. See how often to seal grout. In showers, lower absorption also means joints dry faster after use, which leaves less moisture for mildew. Mildew can still grow on soap film sitting on epoxy, but it stays on the surface where cleaning removes it, instead of staining deep into the joint. More on that in grout mold and mildew.

Chemicals and cleaners

Cement is alkaline and acids attack it. Vinegar, citrus, many bathroom descalers and some "grout cleaners" slowly etch cement grout, widening joints and roughening the surface. Epoxy is much more resistant, which is why ANSI A118.3 materials are standard in commercial kitchens, food processing areas and labs. Resistance isn't universal, though. Each manufacturer publishes a chemical resistance chart, and some concentrated acids and solvents can still damage or stain epoxy. True acid-resistant floors may call for furan or other specialty grouts. To clean safely, check grout cleaners by pH.

Durability and movement

Both are rigid once cured. Epoxy has higher bond and tensile strength, so it's less likely to crack or crumble under traffic, but it won't absorb structural movement any better than cement. If a floor deflects or there are no movement joints, epoxy will crack too, or the stress shifts into the tile. TCNA EJ171 still applies: perimeters, changes of plane and field movement joints get flexible sealant, not grout. See caulk vs grout for movement joints.

UV and color

Older and some current epoxies can yellow or shift color with prolonged sunlight, particularly lighter colors. Many modern products are formulated for better UV stability, and some are approved for exterior use. If the floor is in a sunroom or outdoors, look for explicit UV and exterior claims on the TDS. Cement grout pigments are generally stable in sunlight, though cement grout outdoors faces freeze-thaw and efflorescence issues of its own (see outdoor grout).

Installation: where epoxy demands more

Cement grout is forgiving. If a section firms up before you sponge it, you can usually still clean it with more effort, and light haze comes off a day later. Epoxy doesn't allow that. The usual rules for epoxy are:

• Mix full units in the ratio supplied, or use a scale for partial batches. Off-ratio epoxy may never fully cure, leaving it soft or tacky (see grout not curing).
• Work in small areas, often 10-25 sq ft at a time, and clean as you go with the water and the scrub pad or cleaning additive the manufacturer specifies.
• Keep the substrate and air in the TDS temperature range, commonly around 60-90 deg F (16-32 deg C). Below that, epoxy thickens and cures slowly. Above it, pot life drops sharply.
• Do a final haze cleaning within the window the TDS gives. Once the film cures, it takes a dedicated epoxy haze remover and a lot of scrubbing.

Our step-by-step epoxy grouting guide covers the technique in detail.

Cost, lifespan and repair

Epoxy material costs several times as much as basic cement grout per unit volume, and labor goes up because of the slower, more careful cleanup. Over the life of a shower or kitchen floor, some of that cost comes back: no sealing, less deep cleaning, and less staining that would otherwise lead to regrouting. Cement grout is cheap to install and cheap to fix. Sections can be ground out and replaced with ordinary tools, and color-matching a patch is easier. Epoxy is very hard to remove, so plan on epoxy being permanent (see how to remove grout).

A high-performance A118.7 cement grout is the middle path. You get better color uniformity, lower absorption and better stain resistance than basic sanded or unsanded grout, with cement's easy handling. It still benefits from sealing where staining is likely. See high-performance cement grout.

Which should you choose?

Use the setting and the installer's experience, in that order.

• Commercial kitchen, restaurant, food or chemical exposure: epoxy meeting A118.3, or a specialty grout where the chemical chart requires it.
• Residential shower or tub surround: epoxy if you want no sealing and maximum stain resistance and you're confident with the install; otherwise A118.7 cement grout plus a sealer. Compare options in shower grout.
• Kitchen floor or backsplash with light grout: epoxy or a single-component premixed grout keeps light colors light; cement needs sealing and upkeep.
• Living areas, hallways, low-stain walls: cement grout, preferably A118.7.
• Porous, textured or unsealed tile and stone: cement grout is easier; epoxy only after a release coat and a test.
• Repair or partial regrout of existing cement grout: cement, for color and texture match.
• First-time DIY on a large floor in hot weather: cement, or a premixed grout. Save epoxy for a small, controlled area.

Still undecided? The grout type selector weighs tile, location and maintenance tolerance, and epoxy vs urethane grout covers the main ready-to-use alternative.