LRWA Releases New Electronic Integrity Testing Guidance
The Liquid Roofing and Waterproofing Association (LRWA) has issued Guidance Note 18: Electronic Integrity Testing of Liquid-Applied Membranes, setting a new industry benchmark for verifying the watertightness of flat roofs. The document provides detailed procedures for using electronic integrity testing (EIT) across liquid-applied, hot-melt, reinforced bitumen, and single-ply membrane systems.
Understanding EIT
Electronic integrity testing is a non-destructive method used to detect breaches in waterproofing membranes. By applying an electrical current over the roof surface, it identifies any points where the membrane may be compromised, allowing contractors to address issues before finishes are applied or warranties are issued.
EIT has become the preferred testing approach for modern waterproofing systems because it delivers accurate, repeatable results without flooding the roof or risking moisture ingress.
Why It Matters for Roofing Contractors
For contractors, the new LRWA guidance provides clear, standardised best practice. It sets expectations for timing, preparation, deck suitability, and documentation — helping reduce disputes and ensure test results are reliable.
The guidance also encourages closer collaboration between roofing contractors, system manufacturers, and on-site test houses (OSTHs), ensuring compatibility between membranes and testing methods before work begins.
Key Guidance Points
- Scope: Applies to liquid-applied, hot-melt, reinforced bitumen and many single-ply systems.
- Methods covered: Low-voltage “wet” tests and high-voltage “dry” (holiday brush) tests.
- Best timing: Before covering or overlaying membranes to avoid access issues.
- Deck considerations: Timber and composite decks may reduce accuracy.
- Documentation: Clear reports with test boundaries, photos, calibration data, and signatures are required.
- Manufacturer consultation: Always confirm EIT compatibility before testing.
Contractor Checklist: Preparing for EIT
Before testing begins, ensure the following steps are completed:
- Confirm with the membrane manufacturer that the product is compatible with the intended EIT method.
- Agree on test boundaries and timing with the client and OSTH.
- Ensure the roof surface is clean, dry (for high-voltage testing), and accessible.
- Provide drawings or layout plans for accurate reporting.
- Record all findings and store test certificates with project documentation.
By embedding these steps into your project workflow, contractors can minimise the risk of missed defects and strengthen the technical credibility of their installations.
Relevance for Public-Sector, Education, and Heritage Projects
In sectors where long-term waterproofing integrity is critical, such as hospitals, schools, and heritage sites, EIT provides a measurable assurance that roofs meet the required performance standards before handover.
The LRWA’s guidance reinforces the need for traceable testing, especially on projects involving RAAC roof decks, asbestos overlays, or listed buildings where non-invasive methods are essential. Contractors working under frameworks or local authority specifications can use GN 18 to demonstrate compliance with recognised best practice and reduce the risk of post-completion water ingress claims.
Raising Standards Across the Industry
With GN 18, the LRWA has provided contractors with a structured framework for performing and reporting electronic integrity tests accurately and safely. Adopting these standards helps protect both the installer and the client, while improving quality assurance across the liquid-applied roofing sector.
Contractors using Allbase liquid-applied systems can access full technical support and manufacturer approval for electronic integrity testing, ensuring test compatibility, correct preparation, and accurate certification. Allbase’s technical team provides assistance with EIT procedures, specification advice, and warranty documentation on every project.
You can download a copy of the guidance notes here.
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