ARDEX A 29 is a special cement for producing a rapid hardening floor screed for internal and external use which allows ceramic tiles to be fixed in as little as 24 hours, and natural stone and resilient floorcoverings in as little as 7 days.

USE
ARDEX A 29 is used to produce bonded, unbonded and floating screeds in internal or external locations. A 1:7 mix is suitable for most normal screeding situations. An ARDEX A 29 Screed passes the BRE Screed (ISCR) after 24 hours (tested on 50mm unbonded at 20°C)

Unit Size Available: 20kg

Coverage: 0.27kg ARDEX A 29 cement per m² for each millimetre of screed thickness using a 1:7 mix.

THICKNESS
ARDEX A 29 should be applied at the conventional thicknesses for normal cement/sand screeds i.e. Minimum 20mm at 1:5 ratio and minimum 25mm at 1:7 ratio, (design thickness up to 40mm) for bonded screeds. Minimum 50mm for unbonded screeds. Minimum 75mm for floating screeds. 65mm in lightly loaded (domestic) locations.

MIX PROPORTIONS
Mix a maximum of 1 part by weight of ARDEX A 29 Cement to 7 parts by weight screeding sand.

WATER
Add sufficient water to obtain a workable mix. With an evenly graded, fairly dry sand, the water requirement will normally be up to a maximum of 11 litres per 20kg bag of ARDEX A 29 (including the water contained in the sand/ aggregate).

MIXING
When a sample of mixed mortar is squeezed in the hand the sample should retain its shape and not crumble, the hand being left slightly moist. When a sample is compacted on the base, no film of water should form on the surface. Mix to a normal screed mortar consistency. If a mixer is used it should be a pan, trough or other forced action type. Normal ‘free-fall’ mixers are not suitable for mixing semi-dry screed mortars.

Application on a floor heating system:
When an ARDEX A 29 screed has been laid on a hot water floor system, 7 days should be allowed to elapse before heating the water up to a temperature of 25°C and maintained for a further 3 days. The maximum floor temperature should then be used and maintained for a further 4 days. In doing so draughts must be avoided. The floor should then be allowed to cool down to room temperature (above 15°C) before laying floorcoverings.

Working time at 20°C
approx. up to 90 minutes

Note: Apply an ARDEX A 29 Screed at temperatures of 5°C and rising.

PUMPING
It is possible to pump ARDEX A 29 screed mixes using a proprietary screed pump. Contact our Technical Services Department for further details.

Walkability at 20°C
approx. 8 hours

COMPRESSIVE STRENGTH
After 28 days (1:7 mix) 30 N/mm²
After 28 days (1:5 mix) 40 N/mm²

BRE SCREED TEST
Normally after 24 hours

MOISTURE TESTING
Should the moisture content need to be determined the Speedy Moisture Tester (Carbide method) must be used. Please consult ARDEX Technical Services for further advice.