Description
ARDEX A 45 is a rapid-setting, rapid-drying, slump-free mortar for internal repairs. It dries and hardens quickly to give a repair of exceptional strength and hardness: the mixed mortar sets after 15 minutes and can be trafficked after 1.5 hours at 23 degrees C. Manufactured by ARDEX Australia.
It is the internal counterpart to ARDEX A 46: same slump-free handling, faster to traffic, and able to build from a feather edge to 50 mm once bulked with aggregate. With a suitable epoxy or urethane pigmented finish over it, it can serve as a wear floor in its own right. Also written ARDEX A45.
Technical Specifications
| Product type | Rapid-setting, slump-free cement-based repair mortar |
|---|---|
| Location | Internal only |
| Application thickness | Feather edge to 50 mm (aggregate required above 5 mm) |
| Mixing ratio | Approx. 4.5 litres of water per 20 kg, or about 3 parts powder to 1 part water by volume |
| Working time | 10-15 minutes at 23 degrees C |
| Initial set | 15 minutes |
| Trafficable | 1.5 hours at 23 degrees C |
| Minimum application temperature | Above 10 degrees C |
| Coverage | Approx. 1.6 kg powder per square metre per mm |
| Packaging | 20 kg paper sack with polythene liner |
| Shelf life | 12 months in dry conditions, unopened, at 23 degrees C and 50% relative humidity |
Coverage Rates
ARDEX quotes approximately 1.6 kg per square metre per millimetre — around 12 square metres from a 20 kg bag at 1 mm. On that basis, neat:
| Thickness | Coverage per 20 kg bag |
|---|---|
| 1 mm | Approx. 12 m² |
| 2 mm | Approx. 6 m² |
| 3 mm | Approx. 4 m² |
| 5 mm | Approx. 2.4 m² |
| 10 mm | Approx. 1.2 m² |
| 20 mm | Approx. 0.6 m² |
Above 5 mm the mortar is normally bulked with sand or aggregate, which extends coverage well beyond these neat figures.
Where to Use
- Repairing and refacing concrete stair treads and risers
- Repairing and refacing internal concrete floors
- Filling and patching, forming ramps and coves
- Repairs to walls, ceilings and soffits
- Making good around windows and door frames
- Filling around penetrations
- Wear-type floors, under a suitable epoxy or urethane pigmented finish
How to Apply
- Prepare – surfaces must be dry, set, hardened, sound and free of dust, grease, oil and contamination. Abrade worn or trafficked surfaces with a diamond grinder or scarifier to expose a clean, porous surface. Power-trowelled (burnished) concrete and high-strength concrete above 35 MPa must be mechanically prepared to a CSP3 profile.
- Prime if needed – very dense, smooth, impervious surfaces should be primed with ARDEX P 82. Priming is not usually necessary on porous surfaces such as concrete, cement/sand or brickwork, unless extremely porous. Direct-to-earth sub-floors require an effective damp-proof membrane.
- Mix – add 20 kg of powder to approximately 4.5 litres of water in a clean container and mix thoroughly to a lump-free, slump-resistant mortar. Avoid using too much water. Working time is 10 to 15 minutes at 23 degrees C, longer when cooler and shorter when warmer.
- Bulk out for thickness – over 5 mm and up to 30 mm, add one third volume of sharp sand (0-5 mm) or up to an equal volume of 3 mm single-sized aggregate. For localised depths over 20 mm to 50 mm, incorporate up to an equal volume of 10 mm single-sized coarse aggregate (BS 882 table 4).
- Apply – trowel into holes, cracks and damaged areas so the mortar wets the surface, leaving the repair proud. After about 15 minutes trim off excess and finish with a wet trowel, sponge or sponge float. For smoothing and refacing, finish with a wet trowel after 15 to 20 minutes.
- Finish – once hardened, the surface can be levelled with an ARDEX sub-floor levelling cement if required. High aggregate content mixes may need a second application of neat A 45 to provide a finish suitable for direct application of floor coverings.
Important Notes
- Internal use only. Use ARDEX A 46 for external repairs.
- Apply at temperatures above 10 degrees C.
- Working time is 10 to 15 minutes at 23 degrees C – mix only what can be placed within it, and do not retemper with additional water.
- Direct-to-earth sub-floors require an effective damp-proof membrane before repair.
- Store in dry conditions in the original packaging; storage life is 12 months at 23 degrees C and 50% relative humidity.
Frequently Asked Questions
How much ARDEX A 45 do I need?
Allow approximately 1.6 kg of powder per square metre for each millimetre of thickness. A 20 kg bag covers roughly 12 square metres at 1 mm, 4 square metres at 3 mm, or 2.4 square metres at 5 mm. Above 5 mm the mortar is normally bulked out with sand or aggregate, which extends it considerably.
How thick can ARDEX A 45 be applied?
From a feather edge up to 50 mm. Neat mortar suits thin sections; from 5 mm to 30 mm it should be bulked with one third volume of sharp sand (0-5 mm) or up to an equal volume of 3 mm single-sized aggregate. For localised thicknesses over 20 mm and up to 50 mm, such as deep holes and cracks, incorporate up to an equal volume of 10 mm single-sized coarse aggregate.
Can ARDEX A 45 be used outdoors?
No — it is formulated for internal repairs. For external repairs to concrete floors, walls and stairs use ARDEX A 46, which is designed for exterior exposure. Apply A 45 at temperatures above 10 degrees C.
