Dry steam or water extractor: what each method does to a mat

How a mat tile is built

A puzzle tile or a gym tatami is a foam core (EVA, cross-linked polyethylene or high-density foam) under a textured vinyl surface. The vinyl is waterproof. The foam is not designed to get wet: it holds water in its cells and its cut edges, and it dries slowly. The interlocking seams and the underside are protected by nothing.

What a water extractor does

An extractor injects hot water and a solution under pressure, then vacuums. On a living-room carpet the principle works: the fibres release the dirt and the vacuum recovers most of the water. On foam tiles the water does not stay on the surface: it passes through the seams, soaks the cut edges of the foam and runs under the tile, where the vacuum no longer reaches it. Some of it stays between the mat and the concrete, away from light and air.

This is not a cleaner’s opinion. The maintenance guide from Jukado Mats, the largest tatami distributor in Canada, warns that tatami are not perfectly waterproof: excess water gets into the foam, swells it and delaminates the vinyl; water seeping between tatami breeds fungi and odours, and water reaching the subfloor makes it mould because the surface stops it from evaporating. The same guide rules out mechanical and ride-on scrubbers on tatami vinyl.

• Residual water under the tiles and in the seams
• Long drying: a mat reassembled damp moulds from underneath
• Residual detergent in the foam, sticky on the surface
• No heat action on the underside

What dry steam does

A dry steam generator heats water well past boiling and releases it as low-moisture steam. The heat lifts the greasy film, residues and organic matter off the grain of the vinyl and the seams, and most of it evaporates at once; what remains is wiped or vacuumed. The tile is not soaked. Treated on both faces, it is dry to the touch within minutes, which allows reassembly the same evening.

What neither does alone

Steam sanitises mechanically and through heat, but it is not a registered disinfectant. In Canada, disinfection in the regulatory sense goes through a product carrying a Drug Identification Number (DIN), applied for the dwell time on its label. The full protocol therefore chains disassembly, vacuuming, steam on both faces, registered disinfectant, forced drying and reassembly. Steam prepares the surface; the disinfectant does the regulatory work; drying stops it all from starting again from underneath.

The questions to ask a supplier

A general cleaner will answer “extractor” or “auto-scrubber”, because that is their equipment. The right answer for foam tiles is the third one.

• Do you take the tiles apart or treat the surface in place?
• Which method: water, extractor, dry steam?
• Which disinfectant, which DIN, which dwell time?
• Is the mat dry at reassembly, and how do you check?
• Is there a written report after the visit?