The Waterproofing Accreditation Scheme (WAS) was launched in September 2004.

The aim of this scheme is to ensure minimum competency and raise the capability of waterproofing specialist contractors serving the construction industry in the longer term. It also provides recognition to contractors who are committed to deliver quality waterproofing works.

The scheme was developed jointly by SCI and the Building and Construction Authority (BCA). This scheme is administered by SCI with inputs from Waterproofing Trade Association.  The Real Estate Developers’ Association of Singapore (REDAS) had given their support on the scheme and encourage its members to specify the use of accredited contractors for their projects.

There are three categories of grading under the accreditation; W1, W2 and W3. W1 grade being the highest grade. Waterproofing specialist contractors will be assessed using the accreditation criteria during the accreditation audit. Subsequently, the accredited contractors will be assessed annually for compliance in order to retain its grading.

The accreditation criteria is based on three main criteria.

  • Financial & Track Records
  • Human Resources
  • Quality Management System


Benefits include:

  • Recognise waterproofing specialist who are committed to deliver quality waterproofing works.
  • Awarded full points for the in-process check of internal wet area waterproofing for projects assessed under CONQUAS, if the waterproofing work is carried out by a SCI waterproofing accredited firm. On-site verification is not required.
  • Improved marketability and competitiveness

The inaugural Waterproofing Excellence Award was launched on 15 November 2013 at the SCI 35th Anniversary Gala Dinner at the Swissotel Merchant Court, Singapore

This distinction award recognises SCI accredited waterproofing specialists for their commitment and achievement in delivering high quality waterproofing workmanship. It promotes leading SCI accredited waterproofing firms who have consistently excel in their waterproofing workmanship, setting high quality standards for their workmanship and improve the waterproofing process. The award winners are selected base on the criteria below and the acceptance of the award is voluntarily. There is no need for nomination and application. SCI have implemented this special award for their accredited waterproofing firms to enhance the industry professionalism and increase their quality workmanship of waterproofing performance.

In appreciation of the SCI accredited waterproofing specialists, SCI would like to raise the waterproofing performance even higher through the continuous audit of these firms by their participation in the Waterproofing Accreditation Scheme.


  • The waterproofing firm must be accredited under the SCI Waterproofing Accreditation Scheme.
  • The SCI accredited waterproofing firm have completed at least 5 CONQUAS/QM projects within a period of 3 years.
  • All completed CONQUAS/QM projects within the last 3 years must achieved 100% pass in the internal wet area water-tightness tests.


  • The Waterproofing Excellence Award is given to the firm as a distinction of excellence in quality waterproofing workmanship and for their support of the SCI Waterproofing Accreditation Scheme.
  • For CONQUAS project engaging SCI accredited waterproofing firm with Waterproofing Excellence Award, an extra provisional architectural CONQUAS Bonus Point will be considered.
  • The award-winning firm is given an award certificate and issued with the Waterproofing Excellence Mark.

To know more about the Waterproofing Accreditation Scheme application procedures, Waterproofing Excellence Award and the updated list of Accredited Waterproofing Specialist Contractors, please contact Ms Edina Koh (Tel: 6325 5085, Email: scinst@scinst.org.sg, Contact Us Here ).

You may also wish to download the application form directly from SCI Water Proofing Application_Rev_30-Apr-2024.

Please check our terms and condition Waterproofing Accreditation Scheme T&C.

List of SCI waterproofing accreditation – Refer table below