Repair Systems — 01
Tile adhesive and grout systems — balcony over-membrane
Technical product reference for polymer-modified tile adhesives, epoxy tile adhesives, and grout systems used over waterproofing membranes on balconies and terraces. Covers membrane compatibility, AS/NZS 4992 classification, movement joint requirements, large format tile selection, and brand comparisons for Australian Class 2 strata building applications.
What are tile adhesive and grout systems — balcony over-membrane?
Tile adhesive systems are the materials used to bond ceramic, porcelain, stone, and other tile formats to the cured waterproofing membrane surface on balconies and terraces. In a correctly sequenced balcony waterproofing system, the tile adhesive is the last structural layer before the tile — applied over the cured and flood-tested membrane, it bonds the tile to the system and transfers foot traffic loads back to the concrete substrate below.
In balcony and terrace applications, tile adhesive selection is governed by three factors: compatibility with the specific waterproofing membrane below, flexibility sufficient to accommodate the thermal movement of an external exposed substrate, and compliance with AS/NZS 4992 for the tile format and fixing method being used. External balcony applications impose more demanding conditions than internal wet areas — higher UV exposure, greater thermal cycling, and the risk of prolonged water contact beneath the tile all require a correctly specified, membrane-compatible adhesive system.
Grout systems fill the joints between tiles and complete the tiled surface. In external balcony applications, grout selection must account for joint width, tile format, exposure conditions, and movement joint layout. Sanded cement-based grouts and epoxy grouts each have specific applications and limitations in external balcony use. Movement joints must be incorporated into the tile layout at all perimeters, changes of plane, and at regular field intervals — grout is never used to fill movement joints.
This page covers three product categories: polymer-modified tile adhesive systems, epoxy tile adhesive systems, and grout systems including sanded cement-based and epoxy grout.
Polymer-modified tile adhesive systems
5 products — 2 brands — flexible cement-based adhesives for over-membrane tile fixing on external balconies and terraces
Membrane Compatibility Must Be Confirmed for Every Adhesive Specified
Polymer-modified tile adhesives are not universally compatible with all waterproofing membranes. Each membrane manufacturer specifies which adhesive systems are approved for use over their products. ARDEX membranes are specified with ARDEX adhesives. Mapei membranes are specified with Mapei adhesives. Crossing brands at the adhesive-to-membrane interface without manufacturer confirmation risks adhesion failure and voids the membrane system warranty. Always confirm the adhesive is approved for use over the specific membrane below before specifying.
Minimum 95% Bed Coverage Is Required for External Balcony Tile Fixing
AS 3958.1 requires a minimum 95% adhesive contact coverage for tile fixing in external wet area applications. This means the back of every tile must have adhesive contact across at least 95% of its surface — hollow spots, voids, or ridges beneath tiles are not acceptable in external balcony applications. Full bed coverage is achieved by applying adhesive with the correct notched trowel size, back-buttering the tile where required (particularly for large format tiles), and pressing tiles firmly into the adhesive bed. Tiles with insufficient coverage will fail under thermal movement and water infiltration.
The Tile Adhesive Is Applied Over the Cured Membrane — Not Instead of It
The polymer-modified tile adhesive is the layer between the waterproofing membrane and the tile. It is not a waterproofing product. The membrane must be fully cured, inspected, flood-tested where required, and confirmed compliant before tile adhesive is applied. Applying tile adhesive over an incompletely cured or defective membrane will trap moisture and mask membrane defects — the membrane must be verified before tiling commences.
ARDEX X 77 Microtec
Polymer-modified tile adhesive — Class 2 deformable — microfibre reinforced
Highly flexible polymer-modified tile adhesive — Class 2 deformable — microfibre reinforced — large format porcelain and stone on external balconies and terraces over ARDEX membrane systems
System Description
ARDEX X 77 Microtec is ARDEX Australia's highly flexible, microfibre-reinforced polymer-modified tile adhesive for large format porcelain, ceramic, and natural stone tile fixing on external balconies, terraces, facades, and wet areas. It is classified to AS/NZS 4992 as a Class 2 deformable adhesive — the correct classification for large format tiles (any tile with a side dimension greater than 300mm) on external substrates subject to thermal movement. In balcony waterproofing remediation, ARDEX X 77 Microtec is the standard specification for over-membrane tile fixing where ARDEX liquid-applied membrane systems (ARDEX 8+9, ARDEX WPM 300 series, or similar) are being used. ARDEX confirms X 77 Microtec for use directly over their cured membrane systems — confirm current system approval in the ARDEX system specification or with ARDEX technical before applying. Microfibre reinforcement improves adhesive flexibility and reduces the risk of adhesive cracking under the thermal movement of external exposed tile installations. Applied with a notched trowel — confirm notch size with ARDEX technical for the tile format and substrate condition. Back-buttering of large format tiles (>600mm dimension) is recommended for full bed coverage.
Technical Properties
- AS/NZS 4992 Class 2 deformable — suitable for large format tiles on external substrates
- Microfibre reinforced — improved flexibility under thermal movement
- Single-component — mix with water only
- Suitable for porcelain, ceramic, natural stone, and large format tile formats
- Confirmed for external balcony and terrace applications over cured ARDEX membrane systems
- Extended open time — confirm with ARDEX technical for large balcony applications
Limitations
- Confirm ARDEX membrane system compatibility with current ARDEX system specification before applying — not all adhesives are approved over all membrane types
- Not an epoxy adhesive — not for applications requiring chemical resistance
- Movement joints must be installed per AS 3958.1 — adhesive flexibility does not substitute for movement joints
- Back-buttering required for tiles with any dimension greater than 600mm — confirm trowel size with ARDEX technical
- Confirm current product name and classification with ARDEX Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
ARDEX X 78 Microtec
Polymer-modified tile adhesive — Class 2 deformable — rapid setting
Rapid-setting highly flexible polymer-modified tile adhesive — Class 2 deformable — microfibre reinforced — large format tiles on external balconies and terraces where faster trafficking is required
System Description
ARDEX X 78 Microtec is ARDEX Australia's rapid-setting version of the X 77 Microtec — a highly flexible, microfibre-reinforced Class 2 deformable polymer-modified tile adhesive with faster cure time, allowing earlier grouting and trafficking of the tiled surface. Specified where programme requirements on the balcony remediation project demand faster turnaround between tile fixing and grouting or balcony reinstatement. The product shares the same application method, classification, and membrane compatibility as X 77 Microtec — the key difference is setting speed. Confirm the open time with ARDEX technical for the tile format and ambient conditions before using X 78 on large balcony areas where the faster open time may limit the working area per mix. Back-buttering and 95% contact coverage requirements are identical to X 77.
Technical Properties
- AS/NZS 4992 Class 2 deformable — large format tiles on external substrates
- Rapid setting — earlier grouting and trafficking than X 77 Microtec
- Microfibre reinforced — improved flexibility under thermal movement
- Single-component — mix with water only
- Confirmed for external balcony and terrace applications over cured ARDEX membrane systems
Limitations
- Faster open time than X 77 — confirm working time against the tile format and balcony area before using — shorter open time may require smaller mix batches on large areas
- Confirm ARDEX membrane system compatibility with current ARDEX system specification before applying
- Movement joints must be installed per AS 3958.1 — setting speed does not substitute for movement joints
- Confirm current product name and classification with ARDEX Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Mapei Ultraflex 2
Polymer-modified tile adhesive — Class 2 deformable — EMICODE EC1
Highly flexible polymer-modified tile adhesive — Class 2 deformable — large format porcelain and natural stone on external balconies and terraces over Mapei membrane systems — EMICODE EC1 low VOC
System Description
Mapei Ultraflex 2 is Mapei Australia's highly flexible Class 2 deformable polymer-modified tile adhesive for large format porcelain, ceramic, and natural stone tile fixing on external balconies, terraces, facades, and wet areas. It is the standard Mapei specification for over-membrane tile fixing where Mapei liquid-applied membrane systems (Mapelastic, Mapelastic Foundation, Mapelastic AquaDefense, or similar) are being used. EMICODE EC1 certified — very low VOC emissions. In balcony waterproofing remediation, Ultraflex 2 is specified to ensure system compatibility at the adhesive-to-membrane interface within the Mapei system. Confirm current system approval with Mapei Australia or in the current Mapei system specification before applying over any Mapei membrane. Single-component — mix with water only. Applied by notched trowel — confirm notch size with Mapei technical for the tile format.
Technical Properties
- AS/NZS 4992 Class 2 deformable — large format tiles on external substrates
- Single-component — mix with water only
- Suitable for porcelain, ceramic, natural stone, and large format tile formats
- Confirmed for external balcony and terrace applications over cured Mapei membrane systems
- EMICODE EC1 — very low VOC
- Available in white and grey
Limitations
- Confirm Mapei membrane system compatibility with current Mapei system specification before applying
- Movement joints must be installed per AS 3958.1
- Back-buttering required for tiles with any dimension greater than 600mm — confirm trowel size with Mapei technical
- Confirm current product name and classification with Mapei Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Mapei Keraflex Maxi S1
Polymer-modified tile adhesive — S1 deformable — anti-slump
S1 classified anti-slump flexible polymer-modified tile adhesive — large format tile on external balconies, terraces, and vertical substrates — Mapei membrane compatible
System Description
Mapei Keraflex Maxi S1 is an S1-classified flexible polymer-modified tile adhesive with anti-slump properties, suitable for large format tile fixing on horizontal external balcony and terrace surfaces as well as vertical facade and wall substrate applications. The anti-slump formulation prevents tile slide on vertical surfaces during adhesive open time. S1 classification confirms deformability suitable for external substrates subject to thermal movement. In balcony waterproofing remediation, Keraflex Maxi S1 is specified where the project requires a single adhesive across both the horizontal balcony surface and vertical upstand or wall areas, simplifying product management on site. Confirm membrane compatibility with Mapei Australia before applying over any Mapei membrane system.
Technical Properties
- S1 classified — deformable — suitable for external substrates with thermal movement
- Anti-slump — suitable for vertical facade and wall tile fixing as well as horizontal balcony surfaces
- Single-component — mix with water only
- Large format tile capability — confirm trowel size with Mapei technical
- Suitable for porcelain, ceramic, and natural stone
Limitations
- Confirm Mapei membrane system compatibility with current Mapei system specification before applying
- Movement joints must be installed per AS 3958.1
- Confirm current product name and classification with Mapei Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Bostik UltraSet SuperFlex
Polymer-modified tile adhesive — Class 2 deformable — broad distribution
Highly flexible Class 2 polymer-modified tile adhesive — large format tile on external balconies and terraces — confirm membrane compatibility with both Bostik and membrane manufacturer before applying
System Description
Bostik UltraSet SuperFlex is Bostik Australia's highly flexible Class 2 deformable polymer-modified tile adhesive for large format porcelain, ceramic, and natural stone tile fixing on external balconies, terraces, and wet areas. Bostik is a widely distributed adhesive brand in Australian trade supply, making UltraSet SuperFlex accessible where ARDEX and Mapei system products are not available or where the project is not tied to a single-brand system specification. Where Bostik adhesive is being specified over an ARDEX or Mapei membrane, membrane compatibility must be confirmed with both the adhesive manufacturer (Bostik) and the membrane manufacturer before applying. Cross-brand adhesive-to-membrane combinations are not always covered by either manufacturer's system warranty — confirm in writing before applying.
Technical Properties
- AS/NZS 4992 Class 2 deformable — large format tiles on external substrates
- Single-component — mix with water only
- Suitable for porcelain, ceramic, and natural stone
- External balcony and terrace confirmed
- Available through broad trade distribution in Australia
Limitations
- Confirm membrane compatibility with both Bostik and the membrane manufacturer before applying over any waterproofing membrane system — cross-brand compatibility is not guaranteed
- Movement joints must be installed per AS 3958.1
- Confirm current product name and classification with Bostik Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Epoxy tile adhesive systems
3 products — 2 brands — two-part epoxy adhesives for external balcony and terrace applications requiring chemical resistance or full waterproof bond
Epoxy Adhesives Are Not Routinely Required on Residential Balconies
Epoxy tile adhesives are two-part systems requiring correct mixing ratios, careful temperature management, and skilled application. They are specified where chemical resistance, stain resistance, or a fully impermeable bond is required — typically in commercial food preparation, industrial, or high chemical exposure environments. On standard residential balconies and terraces, a correctly specified polymer-modified Class 2 flexible adhesive is the appropriate specification. Do not specify epoxy adhesive on a residential balcony without a specific technical or project reason — the complexity and cost of epoxy application is not justified by standard balcony conditions.
Mixing Ratio and Temperature Are Critical for Epoxy Adhesive Performance
Two-part epoxy adhesives cure by chemical reaction between resin and hardener — the ratio must be exact. Under-mixing or incorrect ratios produce an adhesive that will not fully cure and will fail in service. Working time is significantly shorter than polymer-modified adhesives and is temperature-dependent — at high ambient temperatures (above 30°C), working time is further reduced. On external balconies in Australian summer conditions, temperature management and smaller batch sizes are essential. Confirm working time, mixing ratio, and temperature limits with the manufacturer before applying.
Movement Joints Are Still Required with Epoxy Adhesive
Epoxy tile adhesives cure to a very hard, rigid bond. They do not provide the same deformability as flexible polymer-modified adhesives under thermal movement. Movement joints per AS 3958.1 are therefore essential with epoxy adhesive systems — the rigid adhesive layer will transmit thermal stress directly to the tile if movement joints are absent. Do not omit movement joints on the assumption that epoxy adhesive will accommodate thermal movement — it will not.
ARDEX WA Epoxy Tile Adhesive and Grout
Two-part epoxy tile adhesive and grout — chemical resistant — combined system
Two-part epoxy tile adhesive and grout — combined adhesive and grout in one product — chemical and stain resistant — external balcony and terrace over ARDEX membrane systems — commercial and high-specification residential
System Description
ARDEX WA is a two-part epoxy tile adhesive and grout in a single product — it functions as both the tile adhesive (fixing the tile to the membrane) and the grout (filling the joint between tiles). This dual function simplifies the material specification where epoxy is required, as a separate grout product is not needed over ARDEX WA. Chemical resistant, stain resistant, and waterproof — appropriate for commercial kitchens, food preparation areas, and high-specification external applications where a fully impermeable tile system is required. In balcony waterproofing remediation, ARDEX WA is specified in high-specification or commercial projects where the client requires a chemical-resistant, stain-resistant tiled surface — not as a routine residential specification. Apply over fully cured ARDEX membrane systems only — confirm membrane compatibility with ARDEX technical before applying. Two-part epoxy — mix resin and hardener in the correct ratio before applying. Working time is temperature-dependent — confirm working time with ARDEX technical for the ambient conditions on the project. Apply in small batches on hot days.
Technical Properties
- Two-part epoxy — tile adhesive and grout combined
- Chemical and stain resistant — fully waterproof cured bond
- External balcony, terrace, and wet area applications
- Confirmed for use over cured ARDEX membrane systems — confirm specific membrane with ARDEX technical
- Available in a range of colours for the grout joint
- Suitable for porcelain, ceramic, and natural stone
Limitations
- Not a routine residential balcony specification — confirm specific technical or project requirement before specifying
- Two-part mixing required — incorrect ratio results in incomplete cure and adhesive failure
- Working time is temperature-dependent — use smaller batches in hot conditions
- Movement joints must be installed per AS 3958.1 — epoxy does not accommodate thermal movement
- Confirm current product name, colour range, and ARDEX membrane compatibility with ARDEX Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Mapei Kerapoxy CQ
Two-part epoxy grout and adhesive — chemical resistant — stain proof
Two-part chemical-resistant epoxy grout and adhesive — stain proof — external balcony and terrace over Mapei membrane systems — commercial kitchens, high-specification residential, and chemical exposure environments
System Description
Mapei Kerapoxy CQ is a two-part epoxy grout and adhesive with self-cleaning properties and chemical resistance, used in commercial food preparation, industrial, and high-specification residential applications where a fully chemical-resistant, stain-proof tiled surface is required. Like ARDEX WA, Kerapoxy CQ functions as both tile adhesive and grout in a single product. Available in a wide range of colours. In balcony waterproofing remediation, Kerapoxy CQ is specified in commercial and high-specification residential projects — not as a routine residential specification. Apply over fully cured Mapei membrane systems — confirm membrane compatibility with Mapei Australia before applying.
Technical Properties
- Two-part epoxy — tile adhesive and grout combined
- Chemical resistant, stain proof — self-cleaning surface properties
- External balcony and terrace confirmed
- Confirmed for use over cured Mapei membrane systems — confirm specific membrane with Mapei technical
- Wide colour range
- Suitable for porcelain, ceramic, and natural stone
Limitations
- Not a routine residential balcony specification
- Two-part mixing required — confirm mixing ratio and working time with Mapei technical
- Movement joints must be installed per AS 3958.1
- Temperature-dependent working time — smaller batches required in hot conditions
- Confirm current product name, colour range, and Mapei membrane compatibility with Mapei Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Mapei Kerapoxy Design
Two-part decorative epoxy grout and adhesive — wide colour range — high-spec residential
Two-part decorative epoxy grout and adhesive — wide colour range — stain resistant — for high-specification residential balcony and terrace applications over Mapei membrane systems where colour and stain resistance are required
System Description
Mapei Kerapoxy Design is Mapei's decorative-grade two-part epoxy grout and adhesive — specified where stain resistance and a high-quality grout joint appearance are required rather than chemical resistance in an industrial sense. Available in an extended colour range, Kerapoxy Design is used in high-specification residential balcony and terrace projects where the client requires a premium grout finish that resists staining from outdoor use, organic matter, and cleaning chemicals. In balcony waterproofing remediation, Kerapoxy Design may be specified in premium residential projects where the tile and grout finish quality is a key project requirement. It is not a routine specification. Confirm membrane compatibility with Mapei Australia before applying.
Technical Properties
- Two-part epoxy — adhesive and grout combined
- Stain resistant — wide decorative colour range
- External balcony and terrace confirmed
- Confirmed for use over cured Mapei membrane systems — confirm specific membrane with Mapei technical
- High-specification residential applications
Limitations
- Not a routine residential balcony specification — specified for decorative and stain resistance requirements
- Two-part mixing required — confirm mixing ratio and working time with Mapei technical
- Movement joints must be installed per AS 3958.1
- Confirm current product name, colour range, and Mapei membrane compatibility with Mapei Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Grout systems — sanded and epoxy
4 products — 2 brands — sanded cement-based and epoxy grouts for external balcony and terrace tile joints
Movement Joints Must Never Be Filled with Grout
Movement joints are installed at all perimeters, changes of plane, columns, penetrations, and at maximum 4.5m field intervals per AS 3958.1. These joints must be filled with a flexible sealant — silicone or polyurethane — after the grout has fully cured. Filling movement joint positions with grout is the most common installation error in external balcony tiling and the primary cause of tile cracking and debonding under thermal movement. Leave movement joint positions clear of grout during grouting, and fill with flexible sealant only after the grout has cured.
Grout Is Not Waterproofing — The Membrane Below Is the Waterproofing Layer
Cement-based grout is permeable. Water will pass through cement grout joints and reach the waterproofing membrane below. This is expected and correct — the membrane below the tile is the waterproofing layer, not the grout. Do not specify grout on the assumption that it will provide waterproofing. The grout joint must be kept to the minimum width required by AS 3958.1 for the tile format, but the grout is a finish material — not a waterproofing product. For a fully impermeable joint, specify epoxy grout.
Grout Colour Selection — External Balcony Considerations
Light-coloured grout on external balconies is susceptible to staining from organic matter, algae, and outdoor use. On external balconies, mid-tone or darker grout colours are generally more practical than white or near-white grouts. Where stain resistance is a priority, specify an epoxy grout or a cement grout with a stain-resistant additive. Confirm colour fastness with the grout manufacturer for the specific exposure conditions of the project before selecting — some cement grout colours fade under UV exposure.
ARDEX Flex Joint (FJ)
Flexible sanded cement-based grout — 2–15mm — UV stable — external
Flexible sanded cement-based grout — 2–15mm joint width — external balcony and terrace — UV stable pigments — ARDEX system compatible
System Description
ARDEX Flex Joint (FJ) is a flexible, polymer-modified sanded cement-based grout for external balcony and terrace tile joints from 2mm to 15mm width. The polymer modification improves flexibility compared to standard cement grouts, reducing the risk of grout cracking under the thermal movement of external exposed tiled surfaces. UV-stable pigments resist colour fade under outdoor sun exposure. Available in a range of colours. In balcony waterproofing remediation, ARDEX FJ is specified as the standard grout for external balcony tile joints where a cement-based grout is appropriate and the joint width is within the 2–15mm range. Applied after tile adhesive has fully cured. Do not grout movement joint positions — leave these clear for flexible sealant.
Technical Properties
- Flexible polymer-modified cement-based sanded grout
- Joint width: 2–15mm
- UV-stable pigments — colour fast under external sun exposure
- Suitable for external balcony and terrace tile joints
- ARDEX system compatible — used in ARDEX tile adhesive system specifications
- Multiple colour options — confirm colour range with ARDEX Australia
Limitations
- Not for movement joints — movement joints must be filled with flexible sealant after grouting
- Cement-based — permeable — not a waterproofing product — the membrane below is the waterproofing layer
- Lighter colours may be susceptible to staining on external balconies — consider mid-tone colours for external use
- Confirm current product name, joint width range, and colour range with ARDEX Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Mapei Ultracolor Plus FA
Fast-setting sanded cement grout — 2–20mm — DropEffect — BioBlock
Fast-setting stain-resistant sanded cement grout — 2–20mm joint width — DropEffect stain resistance technology — external balcony and terrace — Mapei system compatible
System Description
Mapei Ultracolor Plus FA is Mapei's fast-setting, wide-joint sanded cement grout with DropEffect technology — a surface treatment that provides improved stain resistance compared to standard cement grouts. Joint width 2–20mm. Fast setting allows earlier trafficking of the tiled surface after grouting. UV-stable pigments and BioBlock technology resist mould and mildew growth in the grout joint — relevant for external balcony conditions where organic matter and moisture are persistent. In balcony waterproofing remediation, Ultracolor Plus FA is specified as the standard Mapei grout for external balcony tile joints. The stain resistance of DropEffect technology makes it a more practical specification than standard cement grout on external balconies subject to outdoor use and organic staining. Available in a wide colour range.
Technical Properties
- Fast-setting polymer-modified sanded cement grout
- Joint width: 2–20mm — suitable for standard and wider tile joints on external balconies
- DropEffect stain resistance technology
- BioBlock mould and mildew resistance
- UV-stable pigments — colour fast under external exposure
- Mapei system compatible — used in Mapei tile adhesive system specifications
- Wide colour range
Limitations
- Not for movement joints — movement joints must be filled with flexible sealant after grouting
- Cement-based — permeable — not a waterproofing product
- DropEffect provides improved stain resistance but is not equivalent to epoxy grout — specify Kerapoxy CQ or Kerapoxy Design where full chemical resistance or stain proofing is required
- Confirm current product name, joint width range, and colour range with Mapei Australia before specifying
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS and membrane manufacturer before specifying or applying.
Cross-reference — dual-use epoxy system
ARDEX WA
ARDEX WA functions as both tile adhesive and grout. Where ARDEX WA has been specified as the tile adhesive, a separate grout product is not required. See ARDEX WA in the Epoxy Tile Adhesive section above.
Cross-reference — dual-use epoxy system
Mapei Kerapoxy CQ
Mapei Kerapoxy CQ functions as both tile adhesive and grout. Where Kerapoxy CQ has been specified as the tile adhesive, a separate grout product is not required. See Mapei Kerapoxy CQ in the Epoxy Tile Adhesive section above.
Tile adhesive and grout system comparison
Side-by-side comparison of all 12 products across polymer-modified adhesives, epoxy adhesives, and grout systems. Confirm all product selections against the current manufacturer TDS and membrane manufacturer before specifying.
| Product | Brand | Type | AS/NZS classification | Large format tile | Over-membrane confirmed | Key restriction |
|---|---|---|---|---|---|---|
| ARDEX X 77 Microtec | ARDEX | Polymer-modified adhesive | Class 2 deformable | Yes | Yes — ARDEX membrane systems | Confirm ARDEX membrane system compatibility — movement joints mandatory |
| ARDEX X 78 Microtec | ARDEX | Polymer-modified adhesive — rapid set | Class 2 deformable | Yes | Yes — ARDEX membrane systems | Shorter open time — confirm batch size for large areas |
| Mapei Ultraflex 2 | Mapei | Polymer-modified adhesive | Class 2 deformable | Yes | Yes — Mapei membrane systems | Confirm Mapei membrane system compatibility — movement joints mandatory |
| Mapei Keraflex Maxi S1 | Mapei | Polymer-modified adhesive — anti-slump | S1 deformable | Yes | Yes — Mapei membrane systems | Anti-slump — horizontal and vertical applications |
| Bostik UltraSet SuperFlex | Bostik | Polymer-modified adhesive | Class 2 deformable | Yes | Confirm with membrane manufacturer | Cross-brand membrane compatibility must be confirmed in writing |
| ARDEX WA | ARDEX | Two-part epoxy adhesive and grout | Epoxy — confirm AS/NZS class | Yes | Yes — ARDEX membrane systems | Not routine residential — two-part mixing — movement joints mandatory |
| Mapei Kerapoxy CQ | Mapei | Two-part epoxy adhesive and grout | Epoxy — confirm AS/NZS class | Yes | Yes — Mapei membrane systems | Not routine residential — chemical resistance focus — movement joints mandatory |
| Mapei Kerapoxy Design | Mapei | Two-part epoxy adhesive and grout — decorative | Epoxy — confirm AS/NZS class | Yes | Yes — Mapei membrane systems | Decorative and stain resistance focus — not for industrial chemical exposure |
| ARDEX FJ Flex Joint | ARDEX | Flexible sanded cement grout | Confirm with ARDEX TDS | N/A | N/A — grout only | 2–15mm joint — not for movement joints — permeable |
| Mapei Ultracolor Plus FA | Mapei | Fast-setting sanded cement grout | Confirm with Mapei TDS | N/A | N/A — grout only | 2–20mm joint — DropEffect stain resistance — not for movement joints — permeable |
| ARDEX WA (dual use) | ARDEX | Epoxy adhesive and grout combined | Epoxy | N/A | Yes — ARDEX membrane systems | See epoxy section — no separate grout required when used as adhesive |
| Mapei Kerapoxy CQ (dual use) | Mapei | Epoxy adhesive and grout combined | Epoxy | N/A | Yes — Mapei membrane systems | See epoxy section — no separate grout required when used as adhesive |
Do not confuse tile adhesive and grout systems with:
- Waterproofing membranes — tile adhesive is applied over the cured waterproofing membrane, not instead of it — a classified waterproofing membrane must always be present between the concrete substrate and the tile adhesive bed in a compliant external balcony system
- Bedding mortar or sand-cement screed — tile adhesive is a factory-manufactured compound applied by notched trowel in a thin bed — a sand-cement mortar bed is a different system with different thickness, mixing, and substrate requirements — confirm the correct system with the project specification
- Movement joint sealants — movement joints must be filled with a flexible sealant (silicone or polyurethane), not with grout — grout is not a movement joint filler — confusing grout with movement joint sealant is a common installation error that leads to tile cracking and debonding
- Primer or bonding agent — primer or bonding agent is applied to the membrane or screed surface before the tile adhesive — it is a separate product — do not apply tile adhesive directly to an unprimed membrane surface without first confirming with the membrane manufacturer whether a primer is required
- Tile grout and tile adhesive — these are two different products — the adhesive bonds the tile to the membrane — the grout fills the joint between tiles — they are applied in separate operations and must both be specified and confirmed against the membrane system and exposure conditions
Movement Joint Sealant Is a Separate Product — Not Covered on This Page
Movement joints must be installed at all perimeters, changes of plane, columns, penetrations, and at regular field intervals per AS 3958.1, and filled with a flexible sealant — silicone or polyurethane — after grout has cured. Movement joint sealants are not listed on this page. Confirm the correct movement joint sealant with the tile adhesive manufacturer or waterproofing consultant. Do not use grout to fill movement joints under any circumstances.
Disclaimer
This page provides general technical information only. Final product selection must be confirmed against the current manufacturer technical data sheet, project specification, membrane system compatibility, tile format and size, substrate condition, AS/NZS 4992 classification requirements, AS 3958.1 installation requirements, NCC requirements, and movement joint design. Epoxy adhesive systems require specialist application — confirm applicator experience and mixing requirements with the manufacturer before specifying. Do not rely on this reference as a substitute for professional waterproofing consultant or tiling contractor advice.