Gripset C-Bed Cementitious Screed

For residential and commercial floor levelling, new construction, and remedial tiling jobs, Gripset C-Bed Cementitious Screed provides a rapid-hardening, shrinkage-compensated base that can be tiled over or waterproofed in 24 hours. Formulated with select aggregates and polymers, this engineered screed maintains high strength at low builds while resisting the water absorption that causes efflorescence in traditional sand and cement mixes.

How it works

Gripset C-Bed Cementitious Screed is a pre-blended, single-pack system that eliminates the consistency variations of on-site batching. The polymer-modified formulation is slump-free and dimensionally stable, allowing installers to build up ramp areas, grade falls to drains in insitu shower bases, or level uneven concrete floors from 5mm up to 200mm in thickness without cracking. It can be applied directly to prepared concrete, masonry, blockwork, and Gripset wet area membranes as either a bonded or unbonded system.

Numbers that matter

• 5mm to 200mm thickness: The highly adaptable build range allows for thin bonded levelling repairs up to deep screeding and thick ramp installations.
• 24-hour tiling and waterproofing window: Rapid-hardening chemistry allows the application of Gripset wet area membranes and ceramic tiles after 1 day (at 23°C and 50% RH), minimizing site downtime.
• >40 MPa compressive strength (28 days): Provides high-strength load-bearing capacity suitable as an underlayment for demanding floor coverings, including parquetry, vinyl, carpet, and tiles.
• ≥3 hours working time: An extended wet-edge window that gives installers ample time to place, pack, and screed falls before setting begins at 4 hours.
• 0.1m² to 2m² coverage per 20kg bag: Delivers predictable yield calculations, yielding 2m² at 5mm thickness down to 0.1m² at 100mm thickness.

Where to use it

• Underlayment for floor coverings such as carpet, ceramic tiles, vinyl, and parquetry.
• Creating falls and ramps on concrete blocks, masonry, concrete, and Gripset wet area membranes.
• Forming insitu shower bases with required falls to floor wastes.
• Filling holes, voids, and repairing uneven concrete floors before applying levellers like Gripset C-Level.

Bonded vs unbonded installation

For bonded applications down to a 5mm minimum thickness, the screed must be laid over a primed surface. Apply a slurry primer consisting of 1 part Gripset 11Y latex bonding agent to 2 parts C-Bed (by volume) using a medium nap roller or soft bristle broom at 1mm wet film thickness. Place the screed mix directly onto the damp primer in a "wet-on-wet" application.

For unbonded applications at a 40mm minimum thickness, lay the screed over two layers of polyethylene plastic sheet acting as an isolating slip sheet, and incorporate galvanized metal reinforcement in accordance with AS 3958.

Limitations

• Do not use over timber or metal substrates.
• Do not use in fully immersed environments.
• Do not apply when surface or ambient temperatures are below 5°C or above 30°C (note: technical properties table lists 35°C, but application temperature limits are capped at 30°C).
• Do not hand mix or add excess water; require exactly 1.8L of clean water per 20kg bag mixed with a forced action, high-shear stirrer at approximately 600 rpm.
• Do not use in areas subject to hydrostatic head of pressure unless the substrate is first treated with Gripset E60 moisture barrier.
• Concrete substrates must be at least 14 days old before application.
• Protect installed areas from direct sunlight and drying winds during the curing phase to prevent rapid water loss.