Floor Coatings and PTV

Coating categories

• Penetrating sealers — soak into porous surfaces (concrete, natural stone) without forming a separate surface layer; minimal PTV impact when correctly applied
• Topical sealers — form a thin film on the surface; can reduce PTV depending on the chemistry and finish
• Resin overlay coatings — applied thicknesses producing a new surface layer; PTV depends on coating texture, often with embedded grit aggregate
• Polishes and waxes — sacrificial layers refreshed regularly; typically reduce wet PTV through gloss enhancement
• Anti-slip treatments — designed specifically to increase friction, by chemical etching or applied texture
• Decorative coatings — paint, epoxy floor finishes; PTV depends entirely on the finish-coat texture

How coating affects PTV — the directionality

Coatings tend to either preserve or reduce the underlying slip resistance, with anti-slip treatments being the deliberate exception that increases it. Specifically:

• Topical sealers on textured tile typically reduce PTV by 5–15 points
• Polishing waxes on engineered slip surfaces can reduce PTV by 15–25 points over a cleaning cycle
• Resin overlay coatings preserve PTV if the topcoat texture is engineered into the system; reduce PTV substantially if the topcoat is smoothed during application
• Anti-slip etch treatments on polished stone typically increase wet PTV by 10–25 points
• Anti-slip applied coatings (with grit aggregate) increase PTV by 15–35 points but at the cost of visual finish

Sealing porous floors — done right

Concrete and natural stone floors benefit from sealing for protection (against staining, freeze-thaw, oil ingress). Done correctly, sealing has little PTV impact:

• Penetrating sealers (silane-siloxane, silicate, sodium silicate) soak in without forming a film
• Topical sealers can be specified with anti-slip aggregate broadcast into the surface layer
• The sealing operation should preserve the underlying texture, not fill it

Done incorrectly — using gloss sealers without aggregate, applying excess thickness, repeated re-sealing without surface preparation — sealing converts a textured slip-resistant floor into a polished slip-prone one.

Resin overlay floors

Resin overlay flooring (epoxy, polyurethane, methyl methacrylate) is widely used in industrial and commercial environments. The surface friction depends on the topcoat:

• Smooth resin topcoats produce low wet PTV — unsuitable for any wet environment
• Aggregate-broadcast topcoats produce variable PTV depending on aggregate size and density
• Trowel-finish heavy-aggregate systems achieve R12/R13 ratings with high wet PTV
• Decorative quartz-broadcast systems balance aesthetics with moderate slip resistance

Specification should call out both the resin system and the surface texture spec; checking 'epoxy floor' on a procurement document does not specify the slip outcome.

Repair coatings — the silent risk

One of the most common pendulum findings on industrial floors is a localised area of low PTV where a damaged section has been repaired. The repair contractor often applies a smooth fill that masks the originally textured surface. The repair is visually acceptable but creates a localised slip risk that may not be identified until a slip occurs in that exact area.

Best practice for repair specifications: match the original surface texture, not just the visual finish. Periodic post-repair pendulum testing should specifically include the repaired zones.

Anti-slip treatments — when they make sense

Anti-slip treatments are most appropriate where:

• The substrate is intact and visually acceptable
• The slip-resistance shortfall is moderate (PTV gap of 5–25 points)
• The operating environment is not so aggressive that the treatment will be quickly lost
• Surface replacement is not feasible (heritage flooring, listed buildings, operational disruption)

For severely worn, mechanically damaged or fundamentally mis-specified floors, replacement is often a better path than treatment. Treatment verification testing independently confirms the achieved uplift.