Mapei Keracolor GG Cementitious Grout

For grouting joint widths from 4 to 15 mm on interior and exterior floors and walls, Keracolor GG Cementitious Grout provides a polymer-modified, cement-based block against shrinkage cracks. It is formulated for all types of ceramic tiles (single fired, double fired, klinker, porcelain tiles, enamelled porcelain), terracotta, facebrick, and stone material including natural stone, marble, granite, antiqued marble, and agglomerates.

What it does

Keracolor GG is a CG2WA class cementitious grout, signifying improved performance with reduced water absorption and high abrasion resistance under EN 13888 testing. The polymer-modified mix limits shrinkage to prevent cracks and fissures from forming in wide joints. It maintains mechanical strength under freeze-thaw cycles and offers excellent resistance to moisture, ageing, solvents, oils, and alkalis. For installations subjected to heavy traffic, continuous immersion, or harsh weather—such as façades, swimming pools, and bathrooms—mixing Keracolor GG with Fugolastic synthetic resin polymer additive replaces the mixing water to improve the cured physical properties.

Numbers that matter

• 4 to 15 mm joint width: Ideal sizing for rustic finishes, terracotta, klinker, facebrick, and stone panels where wider joints are required.
• 2-hour pot life: Practical working window to mix, apply, and clean up large floor or wall areas before the grout begins to set.
• 24-hour foot traffic: Floors accept light foot traffic after 24 hours, with full service drying achieved after 3 days.
• 7-day pool cure: Basins and swimming pools must cure for 7 days after grouting before filling with water.
• pH >3 acid resistance: Good resistance to mild acids, suitable for domestic and commercial applications where harsh chemical exposure is not anticipated.

Where to use it

This grout is suitable for domestic, commercial, and industrial installations where chemical resistance is not required. Common applications include:

• Exterior façades, balconies, terraces, and swimming pools.
• Rustic flooring finishes such as terracotta, enamelled porcelain, antiqued marble, klinker, and single fired tiles.
• Industrial flooring in dry zones, garages, and warehouses.

Limitations

• Do not mix Keracolor GG with cement or any other products, and never add water to a mix that has begun to set.
• Do not blend different colours of grout together, as this carries a risk of colour inconsistency and non-uniform shades.
• Never mix with salt or dirty water.
• Use only when ambient and substrate temperatures are between +5°C and +35°C.
• The mixing water must be precisely measured. Excess water will cause a whitish calcium carbonate coat (efflorescence) to appear on the surface and can cause different colour tones between batches.
• Do not broadcast dry Keracolor GG powder over filled joints to avoid uneven colouring.
• Do not use where high chemical resistance or hygienic finishes are required; use an anti-acid epoxy grout such as Kerapoxy instead.
• Do not use to fill expansion or distribution joints in floors and walls; these must be filled with flexible MAPEI sealants.
• Rough or micro-porous tiles and stone materials should be tested for cleanability prior to application. If necessary, apply a protective treatment to the tile faces while keeping it out of the open joints.

How to apply

Wait for the installation adhesive or mortar to completely harden before grouting. Ensure joints are clean, free of dust, and cleared to at least 2/3 of the tile thickness. When working in high temperatures, wind, or with highly porous ceramic tiles, wet the joints with clean water first.

Slowly pour Keracolor GG into a clean container holding 18–20% by weight of clean water (or Fugolastic). For floor installations, the mix can be thinned up to approximately 24% water by weight. Mix with a low-speed drill to prevent air bubbles, let the paste stand for 2–3 minutes, then re-stir briefly before application.

Fill the joints using a MAPEI trowel or rubber float, packing the joints completely without voids. Remove excess wet grout diagonally across the joint faces. Once the mix loses its plasticity and turns opaque (typically after 10–20 minutes), clean the tile faces with a damp, hard cellulose sponge. Rinse the sponge frequently using a two-bucket system. Cleaning too early can wash grout out of the joints and cause colour variations, while cleaning too late will require mechanical removal that risks scratching the tiles.