SR25 Surface Retarder


Perma-Colour Surface Retarders are solutions of chemicals which react with cement in the concrete surface and retards the set of the surface layer to a depth of between 3mm and 12mm while the underlying concrete sets. This enables the concrete surface to be removed easily, often by brushing or water blasting and exposes the aggregate to give the depth of the etch to the concrete.


5, 10, 20 & 200ltr drums


These retarders come in two forms:

1 Perma-Colour Surface Retarder - Maximum strength of concrete - 20MPA

2 Perma-Colour Surface Retarder Extra - For concrete strengths over 20MPA


Perma-Colour Surface Retarders are used on horizontal concrete surfaces to produce decorative and non-slip finishes

It can also be used to form a mechanical keyed surface to improve the key of new concrete to old concrete

**As a general rule, the depth of etching should not be greater than one-third of the mean diameter of the aggregate.


The Concrete to be treated should be screeded and lightly trowelled to the desired finish.

Apply the Perma-Colour Surface Retarder after the initial bleed water has disappeared from the surface and before the concrete has started to set. Spraying is by far the most economical form of dispersion of Perma-Colour Surface Retarders. Spray or brush on evenly over the entire surface that has to be treated, taking care that uniform rate of coverage is achieved.


After the concrete has initially cured (up to 24 hours in hot conditions, and 30 hours in cooler conditions), remove the retarded surface laitance by a combination of brushing and/or water jet to reveal a clean exposed aggregate finish.


As the Perma-Colour Surface Retarders are supplied ready-to-use, there is no need for any mixing and MUST NOT BE DILUTED.

If laitance removal is a high powered water blaster, take particular care as not to leave the nozzle aimed in one particular spot for a long time.

Do not leave the treated surface longer than the specified time because a concrete surface will harden and render the retarder useless.

Always Wash out spraying equipment with warm water.



Appearance/Colour: Perma-Colour Surface Retarder - Blue

Perma-Colour Surface Retarder Extra - Green

Specific Gravity: 1.05 - 1.08 - kg/litre

Flash Point: N/A

Viscosity: Low - Medium

Packaging: 5, 10, 20 & 200ltr drums

Shelf Life: 12 months if stored in original, unopened container

Coverage: 4 - 6 m²/ Litre



Some of the Tools Required.