STOPGAP 400 is a fast setting, rapid drying compound for repairing internal floors prior to the application of STOPGAP smoothing under layments in light to heavy duty applications. It is also suitable for use on stairs, steps and general repairs to cracks and holes.

STOPGAP 400 is dimensionally stable and is supplied as a pre-blended dry powder designed for applications between 2-50mm. It is protein-free which allows it to be used in biologically sensitive areas.

STOPGAP 400 is suitable for use over a wide range of subfloor types including sand/cement screed, concrete, sound asphalt, granolithic, terrazzo, epoxy and polyurethane resins, ceramic and quarry tiles and STOPGAP waterproof surface membranes

Standard Mix A 10kg unit of STOPGAP 400 mixed with 2.3 litres of clean water will cover approximately 2m2 at a thickness of 3mm. 1 litre of mortar will cover approximately 1m2 per mm in thickness.

Filled Mix 10kg of STOPGAP 400 powder mixed with an equal volume of STOPGAP GRADED AGGREGATE, mixed with 1 litre of water will cover approximately 0.80m2 at a thickness of 10mm.

Absorbent surfaces - should be dampened with water. Very absorbent surfaces must be primed with dilute STOPGAP P131 primer.

Non absorbent - surfaces must be primed with neat STOPGAP P141 primer. Primer should be used in accordance with the instructions printed on the bottle and must be allowed to dry before applying the repair mortar.

General information

Uniclass 2015

Pr_20_31_53_15 Concrete repair mortarsPrimary


M51/110 Carpeting

Specification data - Concrete repair mortars

Product Reference

Stopgap 400

Product Options

Technical properties:

  • Class (to EN 13813:2002): CT-C30-F4.
  • Working time at 20°C: 10–15 minutes.
  • Setting time at 20°C: 20-30 minutes.
  • At 3 mm ready to receive floor smoothing compounds: 90 minutes
  • Consumption per mm thickness: 1.63 kg/m².

Compressive strength (N/mm², to EN13892-2):

  • 1 Day: >20.0
  • 7 Days: >25.0
  • 28 Days: >30.0

Flexural strength (N/mm², to EN13892-2):

  • 1 Day: >2.0
  • 7 Days: >3.0
  • 28 Days: >4.0