Grout Types Explained: Which Grout for Which Job

Grout isn't just a cosmetic finishing step — the right (or wrong) type genuinely affects how well your tiling holds up over time, particularly in wet areas and anywhere there's movement or heavy use.

Cement-based grout

The most common and affordable type, available as standard or, more commonly now, as a polymer-modified version with additives that improve flexibility, water resistance and stain resistance. Standard cement grout suits most everyday domestic tiling, though a modified version is generally worth the modest extra cost for bathrooms, kitchens, and anywhere grout will be exposed to regular moisture or staining (like a kitchen splashback).

Epoxy grout

Significantly more water-resistant, stain-resistant and durable than cement-based grout, epoxy is the premium option — commonly used in showers, wet rooms, kitchen worktops, and anywhere hygiene or heavy wear is a priority, since it doesn't need sealing and resists mould and mildew far better than cement grout. It costs considerably more, is trickier to apply (it sets faster and is less forgiving to work with), and needs more careful technique to avoid a hazy residue on the tile surface — many DIYers choose to have epoxy grout applied by a professional for this reason.

Sanded vs unsanded grout

Sanded grout contains fine sand, giving it more bulk and preventing shrinkage in wider joints — generally used for joints 3mm and above. Unsanded grout is smoother and used for narrow joints (under around 3mm), delicate or easily-scratched tile surfaces like polished natural stone, and vertical wall applications where sanded grout can be harder to apply neatly. Using sanded grout on a very narrow joint, or unsanded on a wide one, can lead to cracking or shrinkage issues, so matching grout type to your planned joint width matters.

Choosing grout colour

Grout colour has a real visual impact on the finished look — a matching or near-matching colour makes tiling read as one continuous surface and can make small tiles feel larger; a contrasting grout emphasises the individual tiles and pattern, which suits some styles (like metro or subway tiles) particularly well. Darker grout tends to show staining and discolouration less over time than very light or white grout, which is worth factoring in for high-use areas like kitchen floors.

Grout for specific situations

• Underfloor heating — a flexible, modified grout is generally recommended, since the slight expansion and contraction from heating cycles can stress rigid grout over time. See our guide to underfloor heating and tiles.
• Mosaic tiling — with its many small joints, mosaic benefits from a grout that's easy to work into tight spaces cleanly without smearing across the small tile faces.
• Outdoor tiling — needs a frost-resistant, highly water-resistant grout rated for exterior use, since standard indoor grout can crack or fail in freeze-thaw conditions.

Sealing grout

Cement-based grout (including modified versions) generally benefits from a grout sealer, reapplied periodically, to improve stain and water resistance over its lifespan — this is a simple, inexpensive maintenance step that's often skipped but genuinely extends how well grout performs, particularly in kitchens and bathrooms. Epoxy grout doesn't need sealing, which is one of its practical advantages despite the higher upfront cost.

DIY or professional?

Cement-based grouting, done carefully following our step-by-step tiling guide, is a realistic DIY task for most homeowners. Epoxy grouting is more technically demanding due to its faster setting time and less forgiving working properties, and is a reasonable job to hand to a professional tiler even if you've tiled the rest of the area yourself.

How much grout do you need?

Grout coverage depends on tile size, joint width, and grout depth (roughly, the thickness of the tile) — smaller tiles with wider joints use noticeably more grout per square metre than large tiles with narrow joints, since there's simply more joint length to fill relative to the tiled area. Most grout packaging gives an approximate coverage guide based on these factors; as with adhesive, it's worth buying slightly more than the calculated minimum, both to allow for wastage and so that any future repair uses grout from the same batch, since grout colour can vary subtly between batches.

Cleaning grout haze after application

A light haze of dried grout residue on the tile surface is normal after grouting and is removed with a grout haze remover or diluted cleaning solution once the grout has initially set (following the product's specific timing) but before it's fully cured — leaving haze too long makes it considerably harder to remove without risking damage to the tile surface, particularly on polished or textured finishes.