Polymer Modified Grout (PMG) is a type of cementitious grout that includes polymer additives to enhance its performance. These polymers—either liquid latex or redispersible powders—are added to traditional grout mixes (usually made of cement, sand, and water) to improve specific properties like flexibility, adhesion, and water resistance.
🔍 Key Components:
Cementitious Base:
Portland cement
Fine graded sand
Polymer Additives:
Liquid latex (e.g., styrene-butadiene rubber or acrylic)
Redispersible polymer powders (RDP)
Water:
Used to mix the grout (may be reduced if using liquid polymer)
💡 Properties of Polymer Modified Grout:
Property Description
Improved Bond Strength Stronger adhesion to tiles and substrates
Flexibility Reduced risk of cracking due to movement or thermal changes
Water Resistance Better resistance to moisture, making it suitable for wet areas
Durability Enhanced abrasion and chemical resistance
Shrinkage Control Lower shrinkage compared to traditional grout
🧱 Types of Polymer Modified Grout:
Sanded PMG: Contains sand for wider joints (typically 1/8" to 1/2" or more)
Unsanded PMG: No sand; used for narrow joints (less than 1/8")
🏗️ Applications:
Bathrooms and kitchens
Swimming pools and spas
Exterior tiling
Areas with thermal movement or vibration
Commercial floors with heavy foot traffic
🛠️ Advantages:
Excellent workability and smooth finish
Reduced efflorescence
Better resistance to staining and mildew
⚠️ Considerations:
May be more expensive than traditional grout
Curing time may be longer depending on the polymer used
Some require precise mixing ratios for optimal performance
Not always UV stable (depends on polymer type)
✅ Popular Brands and Products:
Mapei Keracolor U or S with Polymer Additive
LATICRETE Permacolor
Custom Building Products Polyblend Plus
Ardex FG-C or FL