Published: 28 January 2026
Protecting an NHS Storage Facility from Groundwater Risk
Codestone House in Poole, Dorset, is undergoing renovation work to serve as a new storage facility for Dorset HealthCare University NHS Foundation Trust. As part of this NHS project, Prokil were appointed to design and install a basement waterproofing solution for important record storage. This required reliable groundwater protection and stable environmental conditions consistent with NHS estate requirements.
Records storage within NHS buildings places specific demands on:
- Moisture control
- Environmental stability
- Long-term resilience
Where areas are exposed to groundwater risk, waterproofing must address both structural protection and the controlled management of water ingress. Prokil delivered a survey-led, compliant solution aligned to the end client’s requirements.
This case study forms part of Prokil’s wider work supporting NHS estates through compliant commercial damp proofing and waterproofing services for NHS trusts.
Designing a Waterproofing Strategy for NHS Records Storage
The area treated at Codestone House supports the Trust’s administrative infrastructure and was designated for use as a records storage facility. This required consistent internal conditions to protect stored documentation and ensure continued accessibility over time. Waterproofing design, therefore, needed to address groundwater protection and long-term environmental performance.
Following a survey, our team developed a waterproofing strategy suitable for below-ground conditions and healthcare use. The presence of groundwater risk informed the decision to specify a combined system approach, rather than reliance on a single method of water resistance.
The adopted strategy focused on:
- Managing groundwater pressure at the structure.
- Providing controlled pathways for water movement.
- Supporting maintainable, long-term performance.
This approach reflects our established methodology for basement and below-ground waterproofing within commercial and public sector buildings, as outlined within our basement and cellar waterproofing services.
Combining Type A & Type C Waterproofing Systems
To deliver the required level of groundwater protection at Codestone House, our team installed both a Type A waterproofing system and a Type C waterproofing system, with each performing a defined role within the overall design.
The Type A waterproofing system involved full preparation of wall and floor surfaces, with existing finishes removed to expose structural substrates. Cementitious tanking was then applied to create a continuous waterproof barrier that resists groundwater pressure and prevents moisture ingress at the source.
Alongside this, a Type C waterproofing system was installed to manage any water entering the structure, and this incorporated:
- A cavity drain membrane applied to walls and floors.
- Perimeter drainage channels at wall and floor junctions.
- Direction of collected water to a sump pump chamber.
The cavity drain membrane allows groundwater to be safely managed without affecting the internal environment, reducing pressure on the building fabric while supporting maintainable long-term performance.
Managing Water Ingress, Power Resilience & Internal Conditions
Water collected within the cavity drain system is directed to a sump pump chamber, allowing groundwater to be mechanically removed and pumped to an external discharge point in a controlled manner. This ensures that water entering the structure is managed without compromising internal conditions within the records storage facility.
To support continued system operation, the pumping arrangement was specified to include a battery backup and an inverter. This provides resilience in the event of power disruption and reduces the risk of water accumulation within the treated area.
To maintain stable internal conditions, a dedicated ventilation system was installed to regulate airflow and humidity. This supports condensation control and contributes to an environment suitable for long-term records storage.
Delivering a Compliant, Operationally Ready Solution for NHS Buildings
At completion, the waterproofing systems installed at Codestone House supported the designated use of the area as a records storage facility. The combined Type A and Type C systems provide structured groundwater protection through resistance and controlled water management. Final works included commissioning the sump pump system, installing power resilience measures, and completing ventilation works to support environmental control, creating stable conditions suitable for long-term operational use.
NHS buildings require waterproofing solutions that are correctly specified, survey-led, and aligned with healthcare estate requirements. Prokil were appointed at Codestone House due to our experience delivering compliant waterproofing solutions within commercial and public sector environments. Our surveyors provide independent assessments and clearly defined recommendations based on building conditions and functional requirements.
Call 0800 048 9488 or arrange an inspection to discuss waterproofing requirements for your residential or commercial property.
