How to choose the right grout

Small detail, big difference.

Grout is one of those decisions that often gets left to the last minute. The tiles are chosen, the layout is planned, and then someone asks: what colour grout?

The right grout can sharpen a design, make a space feel larger, or add a quiet layer of contrast that pulls everything together. Here’s how to approach it.

1. Start with your joint width

Before colour or finish, joint width determines which grout you need. It’s set by your tile type and laying method, so it’s worth knowing upfront.

Rectified tiles, which are cut to precise dimensions, can sit with very tight joints of around 2–3mm. For these, Ardex Flex FS is the right choice. It’s formulated for fine joints up to 4mm, blending to a smooth, uniform finish without streaking. It’s the grout that practically disappears into the layout, keeping the focus firmly on the tile.

For wider joints of 3–15mm, Ardex Flex FL is the one to reach for. It produces a slightly more textured joint, which suits natural stone, handmade tiles, and formats where a little movement and variation are part of the character of the finish. It’s also worth knowing that FL’s slightly coarser texture doesn’t suit very tight joints or polished porcelain, where FS will always give a cleaner result.

For highly demanding environments, Ardex EG 18 Plus Epoxy is worth knowing about. Epoxy-based and chemically resistant, it’s available in four neutral tones and suited to projects where standard flexible grout isn’t quite enough.

2. Matching or contrasting: the grout colour question

This is where most of the creative decision-making happens, and there’s no single right answer. But there are a few reliable principles.

A close match between grout and tile creates the most seamless result. It’s particularly effective with large-format tiles, marble, and stone, where you want the surface to read as one uninterrupted plane. Ardex Flex FS in Brilliant White alongside white or light grey porcelain is a good example. The joint is there for function; it reads as texture, not colour.

Contrasting grout makes the tile format part of the design. Dark grout on a white brick-format tile brings the grid into focus. It’s graphic, deliberate, and works well when the laying pattern is the point. FL’s 35-colour range gives plenty of room to play here, from soft naturals like Stone Beach and Natural Almond through to Cast Iron and Black.

Mid-tones are often underused but worth considering, especially with terracotta, limestone, and warmer neutrals. A grout like Dove Grey or Floating Driftwood can sit between tile and background without disappearing entirely, giving the surface some definition without the sharpness of a full contrast.

3. Finish considerations by tile type

Gloss and polished tiles show grout lines more clearly than matt or textured surfaces. If you’re working with a high-gloss porcelain or a polished marble, a smooth fine-joint grout like FS keeps the finish clean and consistent.

With handmade, zellige, or highly textured tiles, a little variation in the joint is natural and often desirable. FL’s slightly coarser texture sits comfortably alongside surfaces that aren’t perfectly uniform.

The most common mistake is making the decision too quickly. Taking the time to see the colour in your specific room and lighting makes a real difference before you commit. If you’re set on a paler grout in a high-traffic area such as a kitchen floor, it’s worth knowing that a grout sealant like Fila Fugaproof can help protect against staining and keep it looking its best over time.

Still not sure which colour to choose?

Grout colours are always shown as approximates, and that’s worth taking seriously. The same shade can look quite different in a north-facing bathroom versus a south-facing kitchen. If you’re unsure, our teams across all showrooms can help you see the colours in context and alongside tile samples before you commit.

Shop the full Ardex grout range