For interior and exterior tiling jobs where clean, flush joints are required, ARDEX FG8 is a smooth, flexible cement-based grout for joints 1mm to 8mm wide. It contains ARDEX Grout Shield to combat mould growth and is polymer-fortified to reduce the likelihood of cracking, making it suitable for high-visual-impact surfaces such as rectified edged tiles.
ARDEX FG8 fills joints between ceramic, porcelain, glass, terrazzo, quarry tiles, slate, and moisture-insensitive natural stones. The polymer-fortified formulation improves workability to help ensure flush, smooth joints that reduce trapped dirt. Improved colour integrity and low-water application steps reduce the likelihood of efflorescence and shade variations, keeping joints uniform across floors and walls.
Suitable for internal and external walls and floors, including installations over underfloor heating. Compatible substrates include porcelain, ceramic tiles, terrazzo, slate, quarry tiles, glass, and moisture-insensitive natural stones. For timber floors and swimming pools, the grout must be mixed with diluted ARDEX Grout Booster to handle the increased physical movement and moisture exposure.
Ensure joints are clean, free of dust, spacers, excess adhesive, and bedding mortar. Do not begin grouting until the tile adhesive has set firmly. For tiles set on a thick bed of adhesive, ensure the adhesive is fully cured to prevent migrating moisture from affecting the grout colour.
Mix 20kg of ARDEX FG8 powder into approximately 4.2 litres of clean water to achieve a lump-free, creamy mortar. For timber floors and swimming pools, mix with 4.4L of diluted ARDEX Grout Booster (diluted at 80% Booster to 20% water).
Work the grout into the joints using a rubber trowel, compacting it firmly to fill the joints completely. Allow the grout to firm up in the joint, then wipe diagonally across the tile face with a damp, dense sponge. Use minimal water during clean-up to prevent water float, shade variation, efflorescence, and shrinkage. Once the grout has hardened in the joints, polish off any dry film from the tile face with a dry cloth.
Ardex FG8 is polymer-fortified for flexibility, which reduces the likelihood of cracking, especially with movement. It includes Ardex Grout Shield for mould resistance and is designed for strong, uniform colour that reduces efflorescence, preventing common issues with standard grouts.
Yes, for residential swimming pools, Ardex FG8 White (200) mixed with diluted Ardex Grout Booster can be used. Be aware that other colours may bleach over time in chlorinated environments. For public or heavily used pools, Ardex epoxy grouts are recommended due to higher chemical resistance.
The CG2W classification (ISO 13007) indicates a cementitious grout with improved properties (CG2) and reduced water absorption (W). This means Ardex FG8 offers enhanced performance and better resistance to moisture compared to basic cement grouts.
Ardex FG8 is suitable for moisture-insensitive natural stones. For porous natural stones, like some terracotta or absorbent varieties, it is crucial to seal the tiles before grouting to prevent surface discolouration or staining from the grout.
Apply Ardex FG8 when the ambient and substrate temperatures are between 10°C and 35°C. Working outside this range can affect pot life, drying time, and final performance, increasing the risk of issues like inconsistent colour or premature cracking.
| Application | Key benefit | Primary trades |
|---|---|---|
| Grouting general wall and floor tiles | Handles joint widths from 1mm to 8mm, offering broad compatibility for ceramic, porcelain, and natural stone. | Tilers, builders, renovators |
| Finishing rectified edge tiles | Improved workability allows for flush joints and a smooth finish, reducing trapped dirt and enhancing aesthetics. | Tilers, high-end builders |
| Areas prone to mould and dampness | Incorporates Ardex Grout Shield for mould resistance and is water repellent, improving hygiene and appearance in bathrooms and laundries. | Tilers, plumbers, renovators |
| Projects with Green Building Council requirements | Extremely low VOC content meets Green Star IEQ-13 requirements, contributing to healthier indoor air quality. | Builders, architects, certifiers |
| Tiled surfaces with underfloor heating | Suitable for use over underfloor heating systems, preventing cracking due to thermal expansion and contraction. | Tilers, heating installers |
Before mixing, ensure all tile joints are clean, dry, and free from dust, adhesive residue, and any other contaminants. Crucially, all tile spacers must be removed. Check that the tile adhesive has set firmly.
Add the Ardex FG 8 powder to clean water in a clean container. For a 20kg bag, use approximately 4.2 litres of water. Using a mechanical stirrer, mix thoroughly until a lump-free, creamy paste is formed.
Using a high-quality rubber float, work the grout into the joints, applying pressure to ensure they are completely filled and compacted. Move the float diagonally across the tiles to minimise the amount of residue left on the tile face.
Allow the grout to firm up in the joints. Then, use a damp, dense sponge to clean the tile surface, again moving diagonally. Use minimal water to avoid discolouration. Once the grout has hardened, any remaining haze can be polished off with a clean, dry cloth. The area can be opened to light traffic after approximately 24 hours.
Signal Word: Danger
Wear protective gloves, protective clothing, safety glasses with side shields or chemical goggles, and face protection. Use appropriate respiratory protection (e.g., P1 or N95 dust mask for nuisance dust, P3 respirator for significant airborne dust) when mixing or applying to avoid inhaling dust.
Use only outdoors or in a well-ventilated area to minimise inhalation of dust and fumes. Prevent dust concentration in confined spaces.
Store locked up, in original, unopened packaging, in a cool, dry place at 23ºC and 50% relative humidity. Keep containers securely sealed and out of reach of children. Dispose of contents and container to an authorised hazardous waste collection point in accordance with local regulations. Do not allow wash water from cleaning equipment to enter drains.
Proper joint preparation and consideration of tile porosity are critical for achieving a durable, uniform grout finish and preventing common failures.
Surface prep: Joints must be clean, dry, and free from dust, excess adhesive, and bedding mortar. Ensure all spacers are removed. Grout only after the tile adhesive has fully set and cured.
Primer: Not required. For textured or matt tile surfaces, test a small, inconspicuous area first to check for ease of cleaning grout haze.
Surface prep: Joints must be clean, dry, and free from contaminants. All adhesive residues and spacers should be cleared. Allow adhesive to set completely before grouting.
Primer: Not required. Always confirm the stone is classified as moisture-insensitive to avoid issues. Porous stones require pre-sealing.
Surface prep: Ensure joints are clean and dry, as above. The tile adhesive must be fully cured. Pay close attention to cleaning textured surfaces.
Primer: Required. These tiles must be sealed prior to grouting to prevent surface discolouration or staining from the grout. Follow the tile manufacturer's recommendations for suitable sealers.
| Property | Value |
|---|---|
| Mixing Ratio | Approx. 4.2 litres water per 20kg powder |
| Pot Life | 1 hour |
| Drying Time (initial) | 24 hours |
| Drying Time (before sealing) | 7 days |
| Application Temperature Range | 10°C to 35°C |
| Underfloor Heating Compatible | Yes |
| Compression Strength (28 days) | >20 MPa |
| Flexural Strength (28 days) | ≥4 MPa |
| Classification | CG2W (ISO 13007) |
| Swimming Pool Full Cure (before chemicals) | 21 days |
| Shelf Life 20kg Bags | 12 months |
| Shelf Life 1.5kg & 5kg Bags | 24 months |
Here are some common examples on where Ardex FG8 Tile Grout used by our customers.
