Advanced waterproof uncoupling membrane with dovetailed cavities for superior tile adhesion

Available in 10m rolls, this premium uncoupling membrane features a unique dovetailed cavity design that enables a strong tile bond. Manufactured from high-quality materials, it is easy to cut and lays flat for quicker, simpler installation. Ideal for use with underfloor heating systems, and able to be used internally and externally, LokStar Membrane helps protect tiled floors from lateral subfloor movement.

Pack Size - 10m Roll
Material - Polypropylene
Membrane Dimensions (length, width, thickness) - 10m x 1m x 3.5mm
Weight per sq./m - 580g
Resistance to Water Penetration (EN 13984) - Class W1
Water Vapour Transmission Properties (EN 1931) - Sd >100m
Minimum Tile Dimensions - 50mm x 50mm
Minimum Tile Thickness - 5.5mm

Key Features

• Protects tiled floors from lateral subfloor movement
• Unique dovetailed cavity design provides excellent mechanical adhesion
• Easy to cut, simple to install and lays flat
• Ideal for use with underfloor heating systems and over timber floors
• Offers vapour pressure compensation, enabling use on green cementitious screeds and concrete
• Impermeable cavity layer creates a robust waterproof barrier

Areas of Use

• Floors
• Interior and Exterior
• Domestic and Commercial
• Water Piped and Electric Underfloor Heating
• Limited Movement/Vibration

Background and Surface Preparation

Backgrounds must be sufficiently dry and strong enough to carry the total weight being applied. All surfaces must be clean, sound and free from contaminants that could impair adhesion, such as dust, dirt, oil, grease, laitance, and curing agents. Timber bases must be rigid, stable and adequately ventilated. They should support both static and dynamic loads without deflection and be covered with an appropriate intermediate layer.

PRIMER REQUIRED
FOR THE FOLLOWING - PrimeMore Universal

• Cement: Sand Screed (Inc. Heated)
• Concrete
• Plywood & Timber
• Tile Backer Boards

Prime with PrimeMore Universal diluted 1:3 with water. Depending on the porosity of the background, additional diluted coats may be required. The primer must be allowed to dry before fitting the membrane.

PRIMER REQUIRED
FOR THE FOLLOWING - PrimeMore Grip

• Asphalt - (Flooring Grade)
• Epoxy DPM
• Existing Ceramic, Porcelain, and Natural Stone Tiles

Prime with one neat, undiluted coat of PrimeMore Grip. The primer must be allowed to dry before fitting the membrane.

PRIMER REQUIRED 
FOR THE FOLLOWING - PrimeMore CS

• Calcium Sulphate/Anhydrite Screed (Inc. Heated)

Prime with one neat, undiluted coat of PrimeMore CS. The primer must be allowed to dry before fitting the membrane.

Guidance Notes on Suitable Floor Backgrounds

Prime the following backgrounds with PrimeMore Universal, diluted 1:3 by volume with clean water (1 part primer to 3 parts water). Depending on the porosity of the background, additional diluted coats may be required. All coats must be touch dry before applying additional coats or fitting the membrane.

CEMENT: SAND SCREED

• Must be clean and flat.

HEATED CEMENT: SAND SCREED

• New screeds must be commissioned from 3 weeks after screed installation and before work commences.
• Heat slowly at a maximum rate of 5°C per day until the maximum operating temperature is reached. Hold this temperature for 3 days before allowing the screed to cool to room temperature.
• For proprietary screeds, follow the manufacturer’s recommendations for commissioning and preparation.
• The underfloor heating should be switched off 48 hours prior to commencing work.

CONCRETE

• Must be clean and flat.
• Power floated concrete should be mechanically prepared to achieve a clean, sound, micro-textured, dust-free surface.

PLYWOOD (Class 3) & TIMBER

• Tongue and groove timber floors and single layer plywood of the appropriate grade and thickness must be screw fixed into the joists and noggins at a maximum 300mm centres.
• The surface of the timber must be clean and free from contaminants that could impair adhesion, such as varnish, wax, and lacquers.

TILE BACKER BOARDS

• Must be installed as instructed by the manufacturer and be securely fixed to rigid, suitable, prepared bases.
• Where boards have been installed on solid bases using tile adhesive, ensure the adhesive has fully set before commencing work.

Prime the following backgrounds with one neat, undiluted coat of PrimeMore Grip. Allow the primer to dry before fitting the membrane.

FLOORING GRADE ASPHALT

• Must be hard, sound and firmly adhered.

EPOXY DPM

• Must be a flooring grade that is compatible with cementitious products.
• Ensure it is hard, sound and firmly adhered.

EXISTING CERAMIC, PORCELAIN, AND NATURAL STONE TILES

• Must be in good condition, free from contaminants and well bonded.
• Ensure the existing structure can take the additional weight

EXISTING VINYL FLOORING

• Only hard vinyl can be tiled over (cushion vinyl is not suitable and will need to be removed).
• Ensure it is in good condition, free from contaminants and well bonded.

Prime calcium sulphate/anhydrite screeds with one neat, undiluted coat of PrimeMore CS. Allow the primer to dry before fitting the membrane.

CALCIUM SULPHATE/ANHYDRITE SCREED

• All laitance and surface contaminants must be completely removed.
• The screed must be confirmed adequately dry (≤ 85% RH).

HEATED CALCIUM SULPHATE/ANHYDRITE SCREED

• All laitance and surface contaminants must be completely removed.
• New heated screeds must be commissioned from 7 days after screed installation and before work commences.
• The screed should be heated slowly and in accordance with the recommendations of the screed manufacturer.
• The screed must be confirmed adequately dry (≤ 85% RH).
• Switch off underfloor heating 48 hours prior to commencing work.

Green cementitious screeds and concrete do not require priming.

GREEN CEMENTITIOUS SCREED AND CONCRETE

• The membrane can be fitted when unheated green screeds and concrete are load bearing.

ADDITIONAL INFORMATION

Underfloor Heating: LokStar Membrane is suitable for use on heated screeds, underfloor heating overlay systems and electric underfloor heating cables that have been encapsulated in an appropriate Kelmore levelling and smoothing compound.

Lateral Movement: LokStar Membrane is designed to accommodate lateral movement only. Vertical movement (deflection) in subfloors must be eradicated prior to fitting the membrane.

Movement Joints: Do not bridge movement joints with LokStar Membrane.

Uncoupling: To maintain effective uncoupling, the solid adhesive bed beneath the tiles must not exceed 10mm.

Application & Tiling

1. Cut the membrane to size
   • Roll out the membrane wall to wall and cut to the required lengths using a utility knife or scissors. Ensure 6-10mm gap is left around the perimeter of the room.
2. Fitting the membrane
   • Apply a suitable Kelmore tile adhesive to the prepared background using a 6mm × 6mm square notched trowel.
   • Within the adhesive’s open time, roll the pre-cut lengths of membrane, fleece side down, into the adhesive.
   • Use a flat steel trowel or roller to press down and fully embed the membrane. Periodically lift a corner to confirm
   the fleece backing is fully coated with adhesive.
   • Butt-joint all lengths of LokStar Membrane - do not overlap.
   • Remove any adhesive that has come up through the joints during embedding.
3. Tiling
   • Tiling can begin once LokStar Membrane has been installed.
   • Back-fill the cavities using the flat side of the trowel, then comb out the adhesive using an appropriately sized
   notched trowel.
   • Fix the tiles within the adhesive’s open time ensuring they are solid bed fixed.

Please note if tiling commences before the adhesive under the membrane has set, care must be taken to not dislodge the membrane when lifting tiles to adjust the thickness of the adhesive bed.