ARDEX PCT-4 Polished Concrete Topping Grey 25kg

• Product ID: 30583
• Suitable For: locations where a fast-track, polished concrete surface is needed.
• Area of use: INT
• Application Method: trowel
• Volume: 25KG
• Container Type: bag
• Type: concrete
• Colour: grey
• Brand: Ardex
• Manufactuer: Ardex
• Box Size: 1

Substrate Preparation

The substrate must be clean, hard, sound, and free from dust and other barrier materials such as paint, curing agents, laitance, and adhesive residues that may inhibit adhesion. The concrete’s surface strength must be adequate to support ARDEX PC-T 4, with a minimum surface tensile strength of 0.8 N/mm² recommended by BS 8204-3 for concrete bases intended to receive wearing or leveling screeds. Prior to mechanical preparation, use ARDEX DGR degreaser to remove contaminants like polish, wax, grease, and oil. All surfaces must be mechanically prepared using methods such as scabbling, grinding, or contained shot-blasting, and thoroughly vacuumed before priming. Weak, frost-damaged, or overwatered concrete surfaces should be prepared down to sound, solid concrete through mechanical means. Acid etching, adhesive removers, and solvents are not acceptable for cleaning the substrate, and sanding equipment is ineffective for removing curing and sealing compounds. Direct-to-earth concrete subfloors must be dry and equipped with a reliable damp-proof membrane, such as ARDEX DPM 1 C. Moisture levels should be tested using the relative humidity method in accordance with BS 8203-1 and BS 8204-1. It is important to note that any joints or cracks in the concrete base where differential movement is expected, such as movement joints, should be brought through to the finished surface. Before installation, all non-structural dormant cracks should be filled with a fully rigid resin, such as ARDEX PSRS or ARDEX EP 2000. The repair material must be sand broadcast to refusal while still fresh and allowed to cure fully before removing any excess sand. Filling dormant cracks is recommended to help prevent them from reflecting through the topping; however, if movement occurs, cracks may reappear. ARDEX cannot be held responsible for issues arising from joints, existing cracks, or new cracks that may develop after installation.

Priming

All surfaces must be primed using a sand-blinded application of ARDEX R 3 E, or for fast-track installations, ARDEX R 5 E, Solvent-Free Epoxy Primer. The primer should be applied as a complete film coating to the entire area and then broadcast with ARDEX Fine Aggregate to refusal, requiring approximately 1.5 kg/m² of sand. If ARDEX PC-T 4 is to be installed as a thicker aggregated layer, prime as previously described. Once dry and cured, re-prime the top of the aggregated layer before applying a neat layer of ARDEX PC-T 4. For additional information and application guidelines, consult the relevant product datasheet.

Mixing

Mix two bags of ARDEX PC-T 4 at a time, using a maximum of 3.75 liters of clean water per 25 kg bag. Begin by pouring the water into the mixing bucket, then add each bag of ARDEX PC-T 4 while mixing with an ARDEX Cage Whisk and a heavy-duty drill (minimum 650 rpm). Thoroughly mix for about 2 to 3 minutes until a lump-free consistency is achieved, being careful not to overwater. Yellowish foam during mixing or settling of the sand aggregate during installation may indicate overwatering.

Pumping

For large subfloors requiring leveling or thick applications, pumping is recommended. Use a pump to fill and level the area with ARDEX PC-T 4 and aggregate, bringing it within 15-20mm of the finished floor level. The topping can then be poured or pumped as a neat ARDEX PC-T 4 mix. For further assistance, please contact the ARDEX Technical Service Department.

Application

The minimum recommended application temperature is 10°C. Pour the mixed ARDEX PC-T 4 compound onto the prepared subfloor. The mixed mortar will flow during the first 10 minutes of its 30-minute working time at 20°C. Use a pin rake or gauging tool for leveling, and a spiked roller or blade for finishing. For thicker applications, mix ARDEX PC-T 4 with washed and well-graded gravel (3mm to 10mm), ensuring the aggregate size does not exceed one-third the depth of the pour. Mix ARDEX PC-T 4 with water first, then add one part aggregate by volume, mixing until the aggregate is fully coated. Avoid using screeding sand or soft building sand. If the aggregate is wet, reduce the amount of mixing water to prevent overwatering. Adding aggregate may reduce workability, so it may be necessary to apply a neat coat for a smooth surface. Allow the initial application to dry for 12-16 hours before priming and sand broadcasting. The primer should be allowed to dry before removing any excess sand and applying a neat coat of ARDEX PC-T 4. Due to the use of various natural materials in ARDEX PC-T 4, expect some shade or color variations across large pours. Use consecutive batches or blend non-consecutive batches to minimize shading and color differences.

Applications Over Underfloor Heating

ARDEX PC-T 4 can be installed over concrete that contains fully commissioned underfloor heating but should not encapsulate any heating system directly. If underfloor heating is present, it must be turned off, and the concrete or screed should be allowed to cool before installing ARDEX PC-T 4. The underfloor heating system must be commissioned in accordance with the manufacturer’s instructions and according to BS 8204 Part 1 before applying ARDEX PC-T 4.

Polishing and Finishing

ARDEX PC-T 4 wear surfaces are designed to replicate traditional polished concrete and may not appear perfectly homogeneous. The process of spreading, smoothing, and polishing can result in optical variations in the floor’s appearance, even if it is very flat. These variations are an intended effect and should be expected. For detailed instructions regarding the polishing, treatment, sealing, and maintenance of your polished concrete floor, please refer to the Installation and Maintenance Guidance document.

Drying and Hardening

The drying time for ARDEX PC-T 4 depends on site temperature, humidity conditions, and the thickness of the installation. Low substrate temperatures and high ambient humidity may extend the drying time required before processing the surface. Ensure adequate ventilation and heat to facilitate drying, but do not force dry the surface or use surface heaters.