Structural waterproofing - EPG

Structural waterproofing and design services

Protecting structures below ground level demands expert design – not just product selection.

At EPG, we provide fully independent, specialist advice for the design of structural waterproofing systems. Working with developers, contractors, architects and structural engineers, we ensure every solution is tailored, technically robust and fully aligned with current regulations and industry guidance.
Whether you’re constructing a basement, podium deck, blue-green roof or multi-level car park, we provide designs that mitigate risk, reduce long-term liability and integrate with wider structural and drainage strategies.

Why Choose EPG?

Independent & Impartial: We’re not tied to any manufacturer. We specify the right system for the project, not the one we’re incentivised to sell.
Technical Depth: Our team includes CSSW-qualified consultants and experienced designers with decades of combined experience on complex below-ground structures.
Code-Compliant Designs: All designs are fully aligned with BS 8102:2022, NHBC Chapter 5.4, and current best practice guidance.
Audit Trail & CDM: We provide the necessary documentation and justifications for your project file – from risk assessments to detailed drawings, supporting CDM 2015 compliance.
Integrated Approach: We collaborate closely with your structural, civil and architectural teams from RIBA Stage 2 onwards – ensuring waterproofing is considered early and in context.

Our services

Waterproofing risk assessments (in accordance with BS 8102:2022)
Full system specification and detailing for Types A, B and C systems – or hybrid solutions
Below-ground podium and deck waterproofing
Blue, green and blue-green roof design
Review of third-party proposals and value engineering
Site inspections and quality assurance during installation
Coordination with structural and geotechnical design teams

Specialist Design for All Construction Types

Our experience spans a wide range of projects, including:

– Residential basements and deep foundations

– Commercial and mixed-use developments

– Car parks and podiums

– Retaining walls and infrastructure

– Water-retaining and attenuation structures

– Sensitive brownfield redevelopment requiring integrated contamination and waterproofing strategies

Building Safety Act & Early Engagement

The Building Safety Act has placed renewed emphasis on demonstrating that safety-critical design decisions are considered early and appropriately recorded. Structural waterproofing is one such element – it must be integrated with the permanent works design, not applied retrospectively.

Early-stage engagement with a specialist like EPG ensures:

– Holistic risk assessments inform the structure and layout

– Appropriate systems are specified before detailing progresses

– A clear audit trail is established to demonstrate regulatory compliance

– Interfaces with drainage, structural and environmental disciplines are coordinated from the outset

This proactive approach not only reduces design risk but also supports compliance under the Building Safety Act’s duty holder regime and the ‘Golden Thread’ of information.

FAQ

All our designs are supported by up to £10m of professional indemnity insurance. We can also provide a collateral warranty subject to prior agreed.

Basements and other substructures can leak during and after construction and the consequences of this are far reaching and often result in costly remedial works, delays to programme timelines in construction and even expenditure and disruption after construction.

Working with a reliable, independent specialist at the start of your project helps to avoid delays and keeps a development running to schedule.

We will provide robust, cost-efficient and practical waterproofing designs based on rigorous risk assessments. Our design creation considers the associated inputs of the broader design team including, but not limited to, the structural engineer, architect, mechanical, and electrical services engineers along with the needs and requirements of the contractor, client and the building insurer.

We can give accurate assessments of ground conditions including gas contamination, soil permeability, groundwater regime and flood risks in conjunction with the sensitivity of the internal use of the basement structure to ensure the construction is completely sound.

This risk-based, collaborative approach follows the guidance provided in BS8102:2022, The Building Regulations and other advisory documents.

In cases where the podium decks are linked to basements, we consider the deck to be an extension of the basement waterproofing design and apply the same rigorous risk assessments.

Podium decks generally need to facilitate a range of overlying finishes associated with the use of the landscape, including maintenance or emergency vehicular access, soft planted landscaping, activity/play areas and water features. Additionally, podium decks are now routinely incorporated into sustainable drainage systems and utilised as water-attenuating ‘blue-roofs’.

Our designs address the impacts associated with the deck use, which include drainage, irrigation, structural fixings, traffic loading and thermal insulation. Our services extend to full hydrological modelling of drainage and attenuation elements and structural analysis of the load cases for the overlying layers.

To talk to us about your project please fill in the form below, email us on enquiries@epg-ltd.co.uk or talk to us on 01274 565131.

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