Tile adhesive | Chalkline

A tile adhesive is the cementitious or polymer-modified adhesive bonding tiles to a substrate. Classification sits under AS ISO 13007, with a primary class letter and one or more suffix codes describing performance characteristics. Picking the right code for the application is the difference between a 30-year tile and a 3-year debond.

The AS ISO 13007 class codes

Code	Meaning
C1	Cementitious, normal adhesion
C2	Cementitious, improved adhesion
T	Slip resistance (won’t sag on a wall)
E	Extended open time
F	Fast-setting
S1	Deformable (can flex with substrate movement)
S2	Highly deformable

So a code like C2TES1 is improved-adhesion cementitious + slip-resistant + extended open time + deformable. Read left to right; tick each suffix against the job’s requirements.

Picking the class

Application	Minimum
Internal dry walls and floors, small ceramic	C1T
Wet areas (showers, bathroom floors)	C2S1
Large-format tile (≥ 600 mm one side)	C2 with maker’s notch
External walls / paving	C2S1 or C2S2
Natural stone	C2 stain-free formulation
Heated floors	C2S1 minimum
Tile-on-tile	C2 with primer per maker

C2S1 is the residential safe default for any tiled wet area. C1 in a wet area is the callback line.

NOT controlled by AS ISO 13007

Notched-trowel size: set by tile and maker.
Coverage: AS 3958.1 sets the bonded-coverage rule (90% wet / 65% dry).
Curing conditions: temperature and humidity affect set time.

For a builder

Spec by class. “C2S1 from the maker’s range” reads correctly on the tiler’s quote.
Wet areas: never below C2S1. Even a guest powder room qualifies.
Match the notch to the tile. Wrong notch fails AS 3958.1 coverage even if the adhesive is right.

Category: Materials / tiling.

The AS ISO 13007 class codes

Picking the class

NOT controlled by AS ISO 13007

For a builder

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See also

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