Megamortar Stone and Schist Mortar Adhesive
• Megamortar Stone and Schist is a premium grade cement based tile and stone adhesive.
• It is designed for bonding all types of ceramic, stone, mosaic tiles, vitrified and porcelain tiles with
the exception of light coloured and green marble, onto rigid concrete, render, rendered brickwork
and block work surfaces.
• It can be used internally or externally on wall and floor surfaces.
• Megamortar Stone and Schist can be used for fixing low porosity tiles, or tiles in immersed
situations like swimming pools, spas, etc, when mixed with Megamortar Binding Additive and
• Megamortar Stone and Schist when mixed with Megamortar Binding Additive and Primer can be
used for facade tiling application.
• Megamortar Stone and Schist can be used to fix tiles over most waterproofing membranes. However
it is advisable to contact the manufacturer prior to commencing.
• Ensure all concrete slabs are allowed to cure for at least 6 weeks in accordance with AS 3958.1-1991
and have a wood float finish.
• All rendered surfaces must be allowed to cure for at least 7 days prior to commencing tiling.
• Ensure all surfaces are sound, dry and free from movement, oil, dust, grease, wax, curing
compounds, release agents and any other loose contaminating materials.
• Steel trowelled finished concrete surfaces must be mechanically or chemically abraded prior to
• The maximum variation in the plane of the concrete must not exceed 5mm in 3 meters for floors and
4mm in 2 meters for walls.
• It is recommended that all surfaces must be primed with Megamortar Binding Additive and Primer,
especially porous surfaces, to ensure a sound bond of the adhesive to the substrate.
• When applying the Megamortar Binding Additive and Primer to floor surfaces, it is recommended to
firstly pour some primer in a section then spread the primer using a broom, brush or roller. Then
continue this method of application until the entire area is primed. Note: This method of application
ensures a thorough coat of the primer on the surface.
• Allow the primer to dry for approximately 5 minutes at 20ºC prior to commencing tiling.
Expansion / Movement Joints
Expansion/movement joints must be provided to allow for movement between adjacent building
components. They should be as follows:
• Over existing joints in the substrate.
• Where two different substrates meet. Eg. Timber and concrete.
• Around fixed elements in the floor, Eg. Columns.
• At internal vertical corners.
• Around the perimeter of the floor.
• In internal floors where any dimension exceeds 9m or 5m if subjected to sunlight.
• In external floors where any dimension exceeds 4.5m.
• On wall surfaces at storey heights horizontally and approximately 3m-4.5m apart vertically. Ideally
they should be located over movement joints in the structural background and at structural material
changes for example, the horizontal joint at the bottom of floor slabs, vertical joints at internal
vertical corners, and at junctions with columns. (The above points are in accordance with AS3958.1-
• Movement joints should go right through the tile adhesive bed to the background and kept free from
dirt and adhesive droppings. Movement joints must not be less than 5mm and not wider than 10mm.
The movement joints must be filled with a flexible sealant like Silicone.
• The mixing ratio of Megamortar Stone and Schist is 20kg powder to 5 Litres of water.
• Pour 5 Litres of clean water into a drum and then gradually add the Megamortar Stone and Schist
while mixing continuously until a smooth lump free mix is obtained. Always add powder to liquid.
• Allow the mix to stand for 5 minutes, re-stir and then apply the adhesive onto
• Once the surface has been appropriately prepared in accordance with the above instructions, then
apply the adhesive onto the substrate using an appropriate notched trowel.
• For floor tiling use a 10mm x 10mm square notched trowel for tiles up to 300mm x 300mm. For tiles
300mm x 300mm and larger, use a 12mm x 12mm square notched trowel. For mosaic tiles use a
6mm x 6mm square notched trowel.
• For wall tiling use 6mm x 6mm square notched trowel for tiles up to 200mm x 200mm. For tiles
larger than 200mm x 250mm use a 8mm x 8mm or 10mm x 10mm square notched trowel.
• Megamortar Stone and Schist should be applied onto the substrate at a rate of 1m_ at a time.
Application rates greater than this can result in the adhesive skinning before the tiles are laid into it.
• Once the adhesive starts to skin, do not lay tiles into it, but remove it and apply fresh adhesives.
• When placing the tiles into the adhesive press them in by using a twisting or sliding action. Ensure
no voids occur and full coverage of adhesive is under the tiles.
• For tiles with lugs, groves or uneven backing it may be required to butter the back of the tile with
adhesive in addition to trowelling the adhesive onto the substrate.
• The final bed thickness of the adhesive should be at least 2mm for wall tiling and 3mm for floor
• Once the tiling is completed do not disturb the tiled surface for at least 24 hours at 20ºC.
• Excess adhesive from the face of the tiles can be cleaned up with damp cloth while the adhesive is
• Adhesive that has oozed out into the grout joint must be raked out with a knife / spatula etc.
• Tools and other equipment can be cleaned up using water while the adhesive is still wet.
• A 20kg bag of Megamortar Stone and Schist will cover approximately 4-5m_ using a 10mm trowel.
• Grouting application can commence 24 hours after the completion of tiling.
• Refer to grout data sheets for the technical information.
Packaging / Shelf Life:
• Megamortar Stone and Schist is available in 20kg bags.
• A bag of Megamortar Stone and Schist when stored in a cool, dry environment, and off the ground,
will have a shelf life of approximately 12 months.
• Do not apply Megamortar Stone and Schist in temperatures above 40ºC and below 5ºC.
• For fixing tiles in permanently immersed situations like swimming pools or for facade tiling, mix
Megamortar Stone and Schist with Megamortar Binding Additive and Primer.
• For applications / situations not mentioned in this data sheet please contact your nearest Flexco (NZ)
• Megamortar Stone and Schist being cement based is alkaline in nature, and therefore may cause
dermatitis. It is recommended that applicators wear PVC Gloves or similar and safety goggles.
• For a full MSDS on this product, please contact Flexco (NZ) ltd
Source: Megamortar Stone and Schist