Blogs: Get Insights on Waterproofing Solutions & Industry Trends

Competence Counts: What a CSSW Specialist Brings to Your Project

Written by Michaela Rowland | Jul 18, 2025 10:34:21 AM

In today's regulatory landscape, one word rings louder than ever: competence

With The Building Safety Act driving a culture shift, and Gateway 2 submissions placing greater scrutiny on the competence of designers and duty holders, the days of cutting corners in waterproofing are over. The Building Safety Regulator now expects that all those contributing to safety-critical design elements—like waterproofing—can prove they’re up to the job.

That’s where the CSSW qualification comes in. But what is CSSW—and what does having one really say about a person’s capability?

The CSSW Qualification: A Marker of Proven Competence

CSSW stands for Certified Surveyor in Structural Waterproofing. It's a formal qualification governed by the Property Care Association (PCA)—the UK body that sets professional standards for waterproofing practitioners.

To earn it, candidates must undergo:

  • Intensive training
  • Written and oral examinations
  • Ongoing professional development

This isn’t just a tick-box certification. It’s a robust, demanding process that tests real-world understanding, design competence, and technical judgment under pressure.

And increasingly, it’s being seen by developers, architects, and principal designers as the minimum threshold of credibility when appointing a waterproofing specialist.

So, What Does a CSSW-Qualified Individual Actually Know? 

Let's break down the core areas of competence:

  1. Structural Waterproofing Principles

A CSSW-qualified person has a deep understanding of:

  • Type A (barrier), Type B (structurally integral) and Type C (drained) waterproofing systems
  • How to combine or separate these systems appropriately
  • Aligning design strategy with BS 8102:2022 based on risk and usage

They don’t just follow templates—they create bespoke waterproofing strategies that make sense for each unique project.

  1. Groundwater and Soil Behaviour

Competent waterproofing means knowing what’s under your feet. A CSSW specialist assesses:

  • Hydrostatic pressure and groundwater conditions
  • Soil classification and—crucially—whether the soil is free-draining or poorly drained
  • Site topography and how it impacts drainage strategy

Understanding soil behaviour isn't just academic—it determines what waterproofing approach will work and last.

  1. Design & Risk Assessment Capabilities

CSSW-qualified individuals are trained to:

  • Define environmental performance levels (Grades 1–3)
  • Identify potential failure modes, from ingress paths to poor detailing
  • Clarify who is taking responsibility for the waterproofing design

This is a major issue at Gateway 2. If no one’s owning the waterproofing strategy, it’s a red flag. At Premcrete, we back our designs with £10 million PI cover—but the principle applies to all duty holders: someone must take design responsibility.

  1. Waterproofing Systems and Materials Knowledge

A CSSW brings technical confidence around:

  • Cavity drain membranes, cementitious tanking, liquid-applied membranes, bituminous coatings, bentonite sheets, and crystalline admixtures
  • The use of combined systems—especially where waterproofing and gas protection must work together

They understand not just the products, but when to use them, how they perform, and how to sequence them correctly on-site.

  1. BS 8102:2022 and Legal Framework

The CSSW course equips candidates to:

  • Stay up to speed with BS 8102:2022 and its updates
  • Understand duty holder roles under the Building Safety Act
  • Navigate insurance and warranty requirements from bodies like NHBC, LABC, and Premier Guarantee

They help architects and principal designers prove they’ve brought competent specialists to the table—something increasingly required at design gateways.

  1. Surveying and Diagnostic Techniques

CSSW specialists are trained to:

  • Carry out site inspections and diagnose moisture ingress
  • Spot construction defects and poor workmanship
  • Recommend remediation strategies and compile evidenced technical reports

This is vital on refurbishments, failed basements, or any project with legacy risk.

  1. Installation and Detailing Best Practices

Understanding detail is one thing—seeing it done right on-site is another.

While some CSSW outfits operate purely from a desktop, the best specialists combine theory with field experience. At Premcrete, we’re supporting groundworkers and installers daily, across dozens of live projects. That experience sharpens our understanding of:

  • Junctions, upstands, penetrations, and kicker joints
  • Interfacing between systems
  • QA processes and training on-site

Competence comes alive when it’s grounded in the realities of construction.

  1. Drainage and Maintenance Awareness

Especially for Type C systems, drainage is fundamental.

A CSSW-qualified person understands:

  • The need for maintainable systems (accessible channels, serviceable sumps and pumps)
  • Basic design requirements for redundancy and alarms
  • That while we’re not drainage designers, a working knowledge of drainage principles is essential to avoid future failure.
  1. Remedial Waterproofing Techniques

When things go wrong, a CSSW can help with:

  • Injection systems using PU resins or hydrophilic gels
  • Overlays and re-tanking
  • Correcting poor workmanship or mis-specified systems

At Premcrete, we even have a dedicated remedials team that focuses on remediating in the unfortunate event of a defect in the structure or waterproofing installation, that make lead to a leak.

  1. Health, Safety & Environmental Awareness

Competent specialists are also trained in:

  • Safe working in confined spaces
  • COSHH for chemical-based products
  • Sustainability considerations and responsible disposal of waterproofing waste

Waterproofing can be hazardous. The CSSW curriculum ensures professionals understand their duty of care.

Building a Culture of Competence

While one certified person is valuable, a company with a culture of competence is gold.

At Premcrete, we’ve built that culture:

  • Eight team members have undertaken full CSSW training and exams
  • Regular CPD and internal workshops are delivered by trainers who teach the CSSW syllabus
  • Copies of BS 8102 and BS 8485 sit on desks across every department

That kind of embedded knowledge ensures we’re not reliant on one person—we’re all operating to a shared standard of technical competence.

Final Thought: Competence Is No Longer Optional

The Building Safety Act doesn’t just ask for design—it asks for proof of competence.

When it comes to waterproofing, CSSW certification is one of the clearest and most credible ways to demonstrate that. Whether you’re making a Gateway 2 submission, designing a complex basement, or simply trying to de-risk your build—a CSSW-qualified professional is not a luxury. It’s a necessity.

Need expert guidance on your waterproofing strategy?


Work with a CSSW-qualified specialist and futureproof your substructure from the start.
Contact our technical team to discuss your project.