Heat-welded vinyl: a floor with no joints in it.
The detail that separates a clinical, laboratory or kitchen floor from a commercial one. Here is exactly how it is formed, what it demands of the substrate, and where it goes wrong.
Six steps, in this order.
None of them can be swapped or skipped. Most welded-floor failures trace back to a step compressed to save a day.
| Step | What happens | Why it matters |
|---|---|---|
| 1 · Prepare | Old covering lifted, adhesive residue removed, substrate ground or shot-blasted back to sound material | Anything left behind becomes a bond breaker or telegraphs through the sheet |
| 2 · Test | Substrate moisture measured and recorded; damp-proof membrane applied if required | Laying over a wet slab is the single most expensive mistake in flooring |
| 3 · Level | Smoothing compound applied to the flatness the system needs | Vinyl is thin — every ridge and hollow shows, and shows more under raking light |
| 4 · Lay | Sheet set out to minimise seams, scribed to walls, bonded in the specified adhesive | Seam positions are planned, not left to where the roll ran out |
| 5 · Weld | Joints grooved to depth, rod melted in with a hot-air gun once the adhesive has grasped | Groove too shallow and the rod sits proud of the bond; too deep and it bottoms out |
| 6 · Skive | Rod trimmed in two passes — warm with a trim plate, then flush when cool | One hot cut drags the rod and leaves a hollow seam that collects dirt |
Where the floor turns up the wall.
A coved skirting is formed from the same sheet, carried up the wall over a fillet and finished with a capping strip. It is what makes a floor washable rather than merely moppable.
- Coving fillet fixed to the wall-floor junction to form the radius
- Sheet scribed, heated and dressed up the wall, usually 100–150 mm
- Internal and external corners cut, folded and welded closed
- Top edge finished with a capping strip or sealed into a recess
- The junction traps soil that no mop reaches
- Water standing at the angle works under the sheet edge
- A separate skirting leaves a line that has to be sealed and resealed
- Infection-control and food-hygiene audits mark it down
Clinical flooring, where welding is mandatory
The floor is only as good as what is under it.
We will not lay a welded floor over a substrate we have not tested. Where a client asks us to, we put the refusal and the reason in writing, because the failure is not a matter of if.
- Moisture content, measured and recorded
- Surface regularity against the system's tolerance
- Soundness — no laitance, no friable screed, no loose patches
- Residual adhesive and contaminants from the previous floor
- Movement joints identified and carried through the new floor
- Moisture test records
- Material data sheets, batch numbers and fire classification
- Earthing continuity records where a conductive system was installed
- Offcuts retained for future repair matching
Common questions.
What is heat-welded vinyl flooring?
Sheet vinyl laid with the joints grooved out and filled with a matching welding rod melted in by a hot-air gun, then trimmed flush. The rod fuses to both sheets, so the joint becomes part of the floor rather than a gap between two pieces. The result is a continuous, impervious surface.
Why weld at all — is a glued joint not enough?
A glued butt joint is still a joint. Water, cleaning fluid and soil work into it, the adhesive beneath it softens, and the edges begin to lift and curl. In a hospital, laboratory, kitchen or wet area that is also a hygiene failure. Welding removes the gap entirely.
When is welding required rather than optional?
Anywhere the floor is washed down or must be sealed: operating theatres, ICUs, treatment rooms, laboratories, pharmacies, commercial kitchens, toilets, changing rooms and wet play. It is also worth doing in any heavy-traffic corridor, because a welded seam will not open under trolley traffic.
How long after laying can the seams be welded?
The adhesive has to grasp first — typically overnight, and longer in cool or humid conditions. Welding too early is one of the most common causes of failure: the sheet is still able to move, and the weld is put under stress as the adhesive cures. We programme the weld as a separate day's work, not as the tail end of laying.
What is skiving, and why in two passes?
Skiving is trimming the proud welding rod back flush with the floor. It is done in two passes — first with a spatula knife and trim plate while the rod is still warm, taking most of the excess off, then a final pass once it has cooled. Trying to do it in one cut while hot drags the rod and leaves a concave, dirt-catching line down the seam.
Can you weld onto an existing floor?
Only if the existing sheet is sound, well bonded and the same material family, and the manufacturer still supplies a matching rod. More often an older floor has shrunk, so the new sheet and the old will not meet cleanly. We assess it on survey and say plainly whether a patch-in will last or whether the area should be relaid.
Send us the drawings and the specification.
We will confirm the system, the substrate work it needs and a programme with the cure and weld days in it — measured and itemised. New enquiries are normally answered within 48 hours.