A mason's grout choice determines whether a tiled surface lasts 10 years or 30. The difference isn't dramatic until it is then you're looking at failed grout that stains everything, absorbs water, grows mould, and makes you regret every decision.
The Three Main Grout Types
Cementitious Grout The Default
Cementitious grout is Portland cement mixed with sand and additives. Cheap, easy to apply, and for most bathroom and kitchen tiles, fine. Two types: non-sanded (joints under 3mm) and sanded (joints 3mm and above).
Key weakness: it's porous. It absorbs water and stains. It needs sealing after curing. Without sealing, white cementitious grout in a kitchen will look grey within a year.
Polymeric-modified cementitious grouts (Sika Ceram, Fosroc Nitotile) reduce water absorption slightly and improve bond. Sweet spot for most residential work.
Epoxy Grout , When Durability Cannot Be Compromised
Epoxy grout is resin-based. Not porous. Doesn't stain. Doesn't absorb water. Immune to most chemicals.
Mandatory applications: Food plants (bacteria can't be cleaned from porous grout), hospitals, swimming pools (chlorine destroys cementitious), outdoor tiles in monsoon areas, chemical plants and laboratories.
Downsides: short working time (20-30 min), requires 15-30°C application temperature, skilled application needed, 3-4x the cost of cementitious. Some epoxies yellow in UV.
Furan Grout, Extreme Conditions Only
Phenolic resin-based. Immune to almost all chemicals. Up to 120°C. Used in chemical plants, oil refineries. Rarely needed in standard construction. Toxic fumes during application require respirators. (We dont keep this, just for information sake only)
Joint Width Determines Grout Type
Hairline joints (1-2mm): non-sanded only. Narrow joints (2-4mm): non-sanded or epoxy. Medium joints (4-8mm): sanded cementitious or epoxy. Wide joints (8-12mm+): sanded with additives, epoxy, or specialty grouts. (We have been building calculators , please check and let us know how we have built them :-)Â ..
Light-Coloured Grout and Staining
Porous grout absorbs cooking oils, soap scum, minerals from water, and dust. Solutions: use a penetrating siloxane sealer applied 48-72 hours after curing; choose dark grout that hides soiling; or use epoxy which is permanently non-porous.
Application Mistakes That Guarantee Failure
- Sanded grout in hairline joints.
- Not pre-soaking absorbent tiles (grout dries before curing).
- Grouting before adhesive has set (24-48 hours minimum).
- Insufficient joint filling voids and air pockets.
- Water exposure before grout cures (48-72 hours for cementitious, longer for epoxy)
- Mixing grout too thin.
- Using grout as tile adhesive.
Product Recommendations by Application
Residential bathrooms: Polymer-modified cementitious (Sika Ceram, Laticrete, Buildsmart TGE , Fosroc Nitotile) with sealing. Commercial kitchens: Epoxy. High water table ground floors: Epoxy. Swimming pools: Epoxy, non-negotiable. Food processing/hospitals: Epoxy, standard requirement. Outdoor monsoon tiles: Epoxy or water-repellent specialty grout.
Economics
Cementitious grout: ₹5-8/sq ft. Polymer-modified: ₹10-12/sq ft. Epoxy: ₹20-30/sq ft. On a 500 sq ft floor, the difference is ₹10,000-12,000. Failed grout remediation in 5 years: ₹1,50,000+. The maths favours doing it right the first time. (Rs Value will change , is an average and an April 2026 Article Time)
