Stopgap 300 HD

Stopgap 300 HD

Ball, F and Co Ltd Third party certifications:
  • QA Certificate

    QA Certificate

    Certificate type

Fast drying self-levelling smoothing underlayment suitable for use in light to heavy-duty areas.

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STOPGAP 300 is a fast drying self-levelling smoothing underlayment suitable for use in light to heavy-duty areas for preparing sound absorbent and non-absorbent subfloors prior to the installation of new floorcoverings.

STOPGAP 300 is dimensionally stable and is supplied as a pre-blended dry powder designed for application between 2 - 20mm. It is protein-free which allows it to be used in biologically sensitive areas such as hospitals.

STOPGAP 300 is suitable for use over a wide range of subfloor types including sand/ cement screed, concrete, calcium sulphate (e.g. anhydrite), minimal adhesive residues, sound asphalt,granolithic, terrazzo, epoxy and polyurethane resins, ceramic and quarry tiles and STOPGAP waterproof surface membranes.


Absorbent surfaces - Prime with dilute STOPGAP P131 to prevent rapid drying of the underlayment.

For dry (<75% RH) and suitably prepared calcium sulphate screeds, prime with two coats of STOPGAP P121. The first coat should be diluted 1 part primer to 1 part water. Once dry, prime with a second coat of neat STOPGAP P121.

Non-absorbent surfaces – such as sound asphalt, minimal adhesive residues, terrazzo,quarry tiles and STOPGAP waterproof surface membranes should be primed with neat STOPGAP P131 to ensure that good adhesion is obtained between the underlayment and substrate.

Primers should be used in accordance with instructions printed on the bottle and must be allowed to dry before applying the smoothing underlayment.

General information

Uniclass 2015

Pr_35_31_06_80 Smoothing and levelling underlay compoundsPrimary


M10/160 Proprietary self smoothing levelling screeds

M10/7 Proprietary quick drying levelling screeds

M40/460 Smoothing underlayment

M42/10 Wood flooring

M42/110 Wood block flooring

M42/120 Mosaic parquet panel flooring

M42/150 Composition block flooring

M42/20 Composition block flooring

M51/150 Carpeting for stairs

Specification data - Smoothing and levelling underlay compounds

Product Reference

Stopgap 300 HD

Product Options

Technical properties:

  • Class (to EN 13813:2002): CT-C35-F7.
  • Working time at 20°C: 20–30 minutes.
  • Setting time at 20°C: 90 minutes.
  • Consumption per mm thickness: 1.67 kg/m².

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

  • 1 Day: >20.0
  • 7 Days: >25.0
  • 28 Days: >35.0

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

  • 1 Day: >3.0
  • 7 Days: >5.0
  • 28 Days: >8.0

Digital objects

Platform Compatible Version Certified to

Revit 2017




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Third party certifications

  • Quality Assurance - certficate : STOPGAP 300 HD has been tested in accordance with IMO FTPC Part 6(IMO Res. A687(17)) and Annex 2, item 2.2 and approved for use in marine application.STOPGAP 300 HD can be applied to suitably prepared steel decks in light to heavy-dutytraffic areas. USCG approval No. 164.106/1121/WCL MED0528TE

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