How to Install PVC Sheet Flooring: A Complete Step-by-Step Guide

Installing PVC sheet flooring is a precision process that determines not just how the floor looks, but how long it lasts. A poorly prepared subfloor or incorrect adhesive can cause failure within months. A correctly installed floor with heat-welded seams, by contrast, will serve for 25+ years in heavy commercial traffic. This guide covers the complete process.

1. Subfloor Preparation

The subfloor is the foundation of your entire installation. No amount of skill with the flooring itself can compensate for a poor substrate. The surface must be:

• Dry — Relative humidity below 75% for concrete. Use a moisture meter to verify before proceeding.
• Clean — Free of dust, oil, paint, wax, and any loose particles. Vacuum thoroughly, then wipe with a damp cloth.
• Smooth — Unevenness must not exceed 2mm over a 2m straight edge. Any cracks, holes, or undulations must be filled.
• Stable — No movement, crumbling, or delamination of the substrate.

Self-Levelling Compound

For concrete subfloors with significant irregularities, a self-levelling underlayment compound is essential. Apply a suitable primer first, then pour the self-levelling compound at the recommended thickness (typically 2-5mm). Allow 24 hours to fully cure before proceeding. Unitech supplies compatible self-levelling compounds formulated for use with PVC flooring systems.

2. Acclimatisation

PVC flooring rolls must be acclimatised to the installation environment for at least 24-48 hours before installation. Lay the rolls flat (do not stand them on end) in the room where they will be installed. The ambient temperature should be 18-28°C throughout acclimatisation and installation. Cutting the rolls to approximate room dimensions at this stage saves time later.

3. Adhesive Selection & Application

Choosing the correct adhesive is critical. Unitech offers three types depending on the application:

Application Process

1. Apply adhesive with the manufacturer-recommended notched trowel (typically A2 or B1).
2. Spread evenly in one direction — do not overwork the adhesive.
3. Allow the adhesive to become tacky (20-30 minutes for acrylic, depending on temperature and humidity). Test by touching lightly — it should feel sticky but not transfer to your finger.
4. Lay the vinyl sheet carefully, starting from one edge and rolling outward to eliminate air bubbles.
5. Roll the entire floor with a 50-75kg floor roller in both directions immediately after laying.
6. Roll again after 1 hour for maximum bond strength.

4. Heat Welding the Seams

Heat welding creates the seamless, waterproof joints that distinguish professional PVC sheet flooring from amateur installations. This step is mandatory for healthcare, cleanroom, and wet-area applications.

Equipment Needed

• Grooving tool (manual or electric)
• Hot-air welding gun (temperature range 20-620°C, minimum 1,600W)
• 5mm fast-welding nozzle
• Colour-matched PVC welding rod (triangular profile for 2.0mm flooring)
• Trimming knife with skiving blade (quarter-moon shape)
• Seam roller

Welding Procedure

1. Allow adhesive to cure for at least 2 hours before welding.
2. Cut a V-shaped groove along the seam to approximately 2/3 of the flooring thickness using a grooving tool.
3. Pre-heat the welding gun to 350-400°C. Test on a scrap piece first.
4. Insert the welding rod into the nozzle and feed it into the groove at a steady pace. The rod should emerge from the nozzle molten and fill the groove completely.
5. Trim excess rod in two passes: rough trim immediately (while still warm), then finish trim with the skiving blade after cooling. The finished weld should be flush with the floor surface.
6. Roll the welded seam with a seam roller for a smooth finish.

5. Skirting & Finishing

PVC skirting is installed after the flooring adhesive has fully cured (typically 24 hours). For healthcare applications, cove skirting is heat-welded to the flooring at the floor-wall junction, creating a completely sealed, bacteria-proof surface. Standard and self-adhesive skirting options are available for general commercial applications.

6. Curing & First Use

• Light foot traffic: After 24 hours
• Heavy traffic and furniture: After 48 hours
• Wet cleaning: After 5 days
• Initial maintenance: Remove all surface dust with a dry mop. Damp-clean with pH-neutral cleaner.

Common Installation Mistakes to Avoid

1. Skipping subfloor preparation — Uneven subfloors telegraph through the vinyl within weeks.
2. Wrong adhesive — Acrylic adhesive in wet areas will fail. Use PU where moisture is present.
3. Insufficient curing — Heavy traffic before adhesive cures causes sheet movement and seam separation.
4. Cold welding rods — Rods stored in cold conditions become brittle. Store at 15-25°C.
5. Welding too soon — Welding before adhesive cures traps solvent and causes blistering.
6. Inadequate rolling — Air bubbles under the sheet will become permanent defects.