For internal and external wall and floor tiling where high bond strength and slip resistance are required, Gripset C-Mastic Tile Adhesive provides a white, polymer-modified cementitious bed suitable for large-format tiles, glass mosaics, and natural stone. The respirable silica-free formulation improves site safety during mixing, while its non-slump body holds heavy wall tiles in place without slipping.
C-Mastic Tile Adhesive is classified as a C2TES1 adhesive under ISO 13007. It achieves high-strength tensile adhesion (≥1MPa) under dry, water-immersed, and freeze-thaw conditions, making it stable for swimming pools, pool surrounds, and external facades. The S1 deformable rating ensures the cured bed absorbs the lateral shear stresses generated by thermal movement in compressed fibre cement sheeting, plasterboard linings, and over Gripset waterproofing membranes. Its extended open time of 30 minutes prevents premature skinning during large-format floor installations, and it can be applied directly over early-age concrete cured for at least seven days, as well as 24-hour-old screeds and renders.
C-Mastic bonds to structural, porous, and non-porous substrates including:
All preparation and tiling must be carried out in accordance with AS 3958.
Prepare surfaces to ensure they are clean, sound, dry, and free of laitance, curing compounds, and release agents. Steel-trowelled or burnished concrete must be mechanically abraded or primed with Gripset OP Primer.
Prime porous substrates with Gripset GP Primer at a minimum coverage of 1 litre per 8–10m². Prime non-porous substrates with Gripset OP Primer at a minimum coverage of 1 litre per 12m².
Mix one 20kg bag with 5.5 to 6 litres of clean water using an electric stirrer until smooth and lump-free. Allow the mix to stand for 3 minutes, then re-stir. Apply adhesive with an appropriately sized notched trowel, limiting application to 1m² at a time to prevent skinning. For tiles larger than 300 x 300mm, or tiles with lugs, grooves, or uneven backings, back-butter the tile in addition to notching the substrate. Maintain a final minimum bed thickness of 2mm for walls and 3mm for floors. Do not disturb the tiled surface for 24 hours.
Yes, Gripset C-Mastic is engineered for immersed applications, including swimming pools and surrounds. Its C2S1TE classification confirms the high bond strength and flexibility needed for these wet areas. Allow 7 days for curing before filling immersed areas.
No, Gripset C-Mastic is not suitable for direct application onto timber floors or for use with moisture-sensitive natural stone. For timber, differential movement can compromise the bond. For moisture-sensitive stone, the adhesive's properties can cause discolouration or warping.
| Application | Key benefit | Primary trades |
|---|---|---|
| Large format tile installation (internal/external walls and floors) | Non-slump properties and C2S1TE classification ensure secure fixing and accommodate substrate movement. | Tilers, Builders |
| Tiling in immersed areas (swimming pools, pool surrounds) | High tensile adhesion (≥1 MPa after water immersion) and C2S1TE classification provide durability in wet conditions. | Tilers, Waterproofers |
| General internal and external wall and floor tiling | Versatile application across concrete, screed, masonry, and plasterboard with strong, flexible bond. | Tilers, Builders |
| Fixing porcelain, vitrified tiles, and mosaics | Consistent workability and extended open time allow precise placement for various tile types. | Tilers |
| Projects requiring improved health and safety for installers | Respirable silica-free formulation reduces dust-related health risks during mixing and application. | Tilers, Builders, Safety Officers |
Ensure substrates are clean, sound, smooth, dry, and free from contaminants such as dust, oil, grease, curing compounds, or laitance. Mechanically remove unsound layers or contaminants. Follow specific substrate preparation requirements in the adhesion guide.
For dense or steel-trowelled concrete, mechanically abrade using a grinder or abrasive blast to create a textured key.
Prime porous substrates with Gripset GP Primer and non-porous surfaces with Gripset OP Primer as per coverage rates.
Measure 5.5–6 litres of clean water per 20 kg bag. Add C-Mastic powder gradually while mixing with an electric stirrer fitted with a paddle attachment until smooth and lump-free. Allow mix to stand for 3 minutes, then re-stir before use.
Always add powder to water (not vice versa) to achieve optimal consistency and avoid lumps.
Only mix quantities that can be applied within the 1-hour pot life to maintain bond integrity.
Apply adhesive to the substrate using the correct size notched trowel for the tile size. For tiles >300×300 mm, back-butter in addition to notching the floor/wall. Spread no more than 1 m² at a time to prevent skinning before laying tiles.
Press tiles into adhesive with a sliding action to achieve full contact and avoid voids.
Use a 12, 15, or 20 mm notch and back-butter tiles to achieve full coverage in compliance with AS 3958.
Allow at least 24 hours before grouting. Protect tiling from rain and moisture during curing. In wet areas, wait 3 days before service; in immersed areas, allow 7 days before filling.
Begin once adhesive has cured and tiles are secure, removing any adhesive from joints before grouting.
Allow a longer curing period in humid or cold conditions to ensure full adhesive set before exposure to moisture.
Danger: Causes skin irritation. Causes serious eye damage. May cause respiratory irritation.
Wear safety shoes, overalls, gloves (nitrile rubber recommended), safety glasses, and a dust mask. Wash hands before eating, drinking, or smoking. Wash contaminated clothing before reuse.
Use only outdoors or in a well-ventilated area. Ensure adequate ventilation to maintain air concentrations below exposure standards and to avoid inhaling dust.
Store in original unopened packaging for up to 12 months in a cool, dry, well-ventilated place, out of direct sunlight. Keep away from foodstuffs and incompatible materials. Avoid freezing and cold floors. Store locked up. Dispose of contents/container according to local regulations.
Proper surface preparation and priming are critical for ensuring adhesive performance and preventing bond failure.
Surface prep: Clean, sound, dry, and free from contaminants. Steel-trowelled, burnished, or dense surfaces require mechanical abrasion to create a key.
Primer: Optional. Use Gripset OP Primer if mechanical abrasion is not performed on dense concrete.
Surface prep: Clean, sound, dry, and free from contaminants. Structurally unsound layers must be mechanically removed.
Primer: Required for porous/absorbent surfaces. Use Gripset GP Primer at 1 litre per 8-10m².
Surface prep: Clean, sound, dry, and free from contaminants. Ensure surfaces are stable and constructed to manufacturer recommendations.
Primer: Required for porous/absorbent surfaces. Use Gripset GP Primer at 1 litre per 8-10m².
Surface prep: Mechanically abrade/roughen the surface to remove at least 80% of the tile glaze for direct fixing. Clean thoroughly.
Primer: Optional. Use Gripset OP Primer if mechanical abrasion is insufficient or preferred.
Surface prep: Ensure membrane is clean, fully cured, and free from contaminants.
Primer: Not required over Gripset waterproofing membranes.
| Property | Value |
|---|---|
| Form | Powder |
| Colour | White |
| Bulk Density | 1.18 kg/dm³ |
| Tensile Adhesion Strength 28 days dry | ≥1 MPa |
| Tensile Adhesion Strength Water Immersion | ≥1 MPa |
| Tensile Adhesion Strength Freeze/Thaw | ≥1 MPa |
| Classification | C2S1TE |
| Open Time | 30 minutes |
| Adjustment Time | 40 minutes |
| Pot Life | 1 hour |
| Ready for Grouting | 24 hours |
| Light Foot Traffic | 24 hours |
| Wet Area Service | 3 days |
| Immersed Areas Service | 7 days |
| Shelf Life | 12 months |
Here are some common examples on where Gripset C-Mastic Tile Adhesive used by our customers.
