Why a clinical floor is welded, not glued.
A seam is where a floor stops being a surface and starts being a joint. In a clinical area, that distinction is the whole specification.
A welded floor is one surface.
Everything else about clinical flooring follows from this single requirement.
Sheet vinyl arrives in rolls, so any area wider than the roll has joints. Left butted or simply glued, each joint is a line that liquid can enter and that cleaning cannot fully reach. In a ward, a theatre or a treatment room, that line is a contamination path and a cleaning validation problem.
Heat welding closes it. The joint is routed to a consistent profile, a matching welding rod is fed in with a hot-air gun, and the rod fuses with both sheets. Once trimmed flush the joint is continuous material rather than two edges in contact. The floor can then be cleaned as a surface, which is what a clinical cleaning regime assumes.
The same logic drives the perimeter. A square junction between floor and wall traps soil and cannot be cleaned reliably, so the vinyl is turned up the wall over a cove former to create a radius, and the top edge is closed with a capping strip. A floor with perfect welds and a square skirting detail has solved half the problem.
What a correct weld looks like.
Welding is a trade skill with a narrow window, and the failures are recognisable.
| Symptom | Cause |
|---|---|
| Rod lifting out of the groove | Groove too shallow or inconsistent; rod not keyed |
| Scorched or glazed rod | Gun too hot, or travel speed too slow |
| Weak joint that opens later | Gun too cool, or travel speed too fast for fusion |
| Hollow or dished weld | Over-trimmed, usually trimmed in one pass while hot |
| Seam opening weeks later | Welded before the adhesive had cured, so the sheet still moved |
The last of those is the one that catches programmes rather than tradesmen. Welding is normally held until the adhesive has cured, because a sheet that can still move will carry that movement into the joint. A floor welded the same day it was laid can look perfect at handover and open at the seams a month later.
Trimming is the other place skill shows. The rod is usually trimmed in two passes — a first cut while warm using a trim plate to protect the sheet, a second once cool — to leave the weld flush rather than dished. A dished weld is a shallow channel, which defeats the purpose.
Theatres, wet rooms and anywhere with a drain.
Not every clinical space has the same requirement, and specification should follow use.
- Operating theatres: welded seams, coved perimeter, and in many cases a conductive or static-dissipative system with an earthing network
- Wards and treatment rooms: welded seams and coving, with slip performance appropriate to the area
- Sluices, wet rooms and kitchens: welded seams, coving, and a slip-resistant grade that remains effective wet
- Corridors: welded seams, with attention to doorway thresholds where rolling loads concentrate
Conductive systems add a layer of discipline: copper tape grid, conductive adhesive, and a continuity test at completion with the result recorded. A conductive floor that has never been tested is a claim, not a specification.
Questions we are actually asked.
What is the difference between a welded and a glued seam?
A glued or butted seam is two sheet edges held in contact, which leaves a line that liquid can enter and cleaning cannot fully reach. A heat-welded seam is routed and filled with a matching rod that fuses to both sheets, so the joint becomes continuous material and the floor behaves as a single cleanable surface.
When should welding be carried out after laying?
After the adhesive has cured, not on the same day. A sheet that can still move will transfer that movement into the joint, which is a common cause of seams opening weeks after an installation that looked perfect at handover.
What is coving and why is it needed?
Coving turns the vinyl up the wall over a former so the floor-to-wall junction is a radius rather than a square corner, finished with a capping strip at the top edge. A square junction traps soil and cannot be cleaned reliably, so coving completes what welded seams start.
How do you tell a good weld from a bad one?
A correct weld sits flush with the sheet, with no scorching or glazing and no dishing. Hollow welds are usually over-trimmed, scorched rod means the gun was too hot or too slow, and a weak joint means it was too cool or too fast. All are visible on close inspection before handover.
Do operating theatres need conductive flooring?
Often, depending on the equipment and the specification. Where a conductive or static-dissipative system is specified it needs a copper earthing grid, conductive adhesive and a continuity test at completion with the results recorded, otherwise the performance cannot be demonstrated.
Send us the room schedule.
We will set out the system for each area, the welding and coving detail, and what testing is recorded at handover.