Heat-welded seams in sheet vinyl: when and why

Sheet vinyl comes in rolls, typically around two metres wide, so any room bigger than one roll width has seams. In a home laundry, a neat butt join may be all you need. In a clinic, a childcare bathroom or a commercial kitchen, an open seam can collect dirt and moisture. Heat welding closes it. This guide covers what heat welding is, where it is used and what to look for.

What heat welding is

Heat welding fuses a thermoplastic weld rod into a groove cut along the seam between two sheets. The installer routs a channel down the join, uses a hot-air welding gun to melt the rod into the groove, and trims the rod flush once it cools. Done properly, the two sheets and the rod form one continuous surface with no gap for water, bacteria or cleaning chemicals to get into.

Weld rods come in matching or contrasting colours. Most commercial projects use a matched rod so the seam is barely visible. Some healthcare and education projects choose a contrasting rod on purpose, either for wayfinding or to make inspection easier.

Where welded seams are expected

• Healthcare treatment rooms, consulting rooms and wet areas
• Aged care bathrooms, ensuites and corridors
• Childcare bathrooms, nappy change and kitchen areas
• Commercial kitchens and food handling zones
• Laboratories and other spaces with frequent wet cleaning
• Amenities and change rooms in workplaces

If you are working to an architect’s or builder’s specification, it will usually say whether welded seams are required. If you are not sure, tell us how the room will be cleaned and what spills it might see.

Heat welding and coving together

Welded seams are often paired with cove skirting, where the vinyl is turned up the wall on a cove former instead of finishing with a separate skirting board. Internal and external corners are formed and welded too. The result is a tray-like surface with no open joint at the floor and wall junction. This detail takes time and skill, which is why we quote it as a separate line instead of hiding it inside the square-metre rate.

What a good weld looks like

• The rod sits flush with the floor, with no ridge to catch dirt or trip on
• The weld is continuous, with no gaps, burns or scorch marks
• Seams are placed sensibly, out of main traffic paths where the layout allows
• Pattern or texture is aligned across the seam on patterned products
• Corners on coved edges are fully welded and neat

A bad weld is easy to spot after a few months: dark lines where dirt has collected in an unsealed groove, or edges lifting where the rod did not fuse.

Preparation still comes first

Welding cannot fix a poor substrate. If the slab is uneven, seams can peak or gap over time. Moisture in the slab can affect adhesives and cause bubbles near the seams. We check the substrate and quote floor preparation, including levelling, grinding or moisture treatment, before any welding is scheduled.

Homogeneous, heterogeneous and welding

Both homogeneous and heterogeneous commercial sheet vinyls are commonly welded, though the rod and technique can differ by product. Always follow the manufacturer’s instructions for the specific range. We install to those instructions so warranties are protected.

Timing and access

Welding usually happens after the sheet has been laid and the adhesive has had time to set, according to the product system. That can add time to the program, especially in occupied facilities where rooms are done one at a time. We plan the sequence with you before work starts.

Where welded seams are usually expected

• Confirm whether the specification calls for welded seams
• Choose weld rod colour: matching or contrasting
• Confirm cove height and any capping strip
• Allow program time for welding and trimming

Getting a quote

Send us the room list, any specification and photos or drawings, and say whether coving is required. Request a commercial quote and 8K Flooring Group will measure and price welded sheet vinyl for your project. We are based at 14 West Court, Coolaroo VIC 3048 and work across Melbourne.