The Royal Derby Hospital

External car park refurbishment
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Refurbishment of the Hospitals car park to restore long-term waterproofing and surfacing.
Uttoxeter Road, Derby
December 2018
Authorised Contractor
Concrete Repairs Ltd.

Key points

  • The solution was fast and simple to apply, allowing authorised installers from CRL to finish the refurbishment in a short time frame and minimise disruption to staff and visitors.
  • CRL were not too concerned about rain disrupting progress, because all elements of Triflex ProPark can be installed and fully cured in a working day.
  • Triflex surveyed the site and tested the substrate in advance to provide complete peace of mind.
  • The car park is now open with a long-term waterproofing solution that will see out its remaining PFI (Private finance initiative) maintenance period.

The challenge

The Royal Derby Hospital

Ten years after its construction, the car park’s waterproofing system at The Royal Derby Hospital had come to the end of its warranted life and was no longer protecting the structure. If left as it was, there would be a risk of longterm structural damage through chloride ingress, in addition to contaminated and potentially caustic water dripping onto cars and people below.

The car park is the first impression that many patients and visitors have of the hospital, so it was important to upgrade the facility for both future safety and for the trust’s image and reputation.

Skanska maintains and manages the car park as part of a PFI contract with the trust and were keen to find a system that would not only minimise disruption during installation, but would also extend the waterproofing warranty beyond the lifetime of their agreement. The Triflex system being cold liquid applied, solvent-free and rapid curing, made the installation safe, easy and fast to apply.

It was agreed that the refurbishment would take place over the summer holidays, because past records show that the hospital is less busy over this period, so there would be less disruption to staff and visitors.

The solution


The Triflex Technical Team visited the site to complete a survey of the car park, which assessed the structure’s existing waterproofing. Other areas such as joints, drainage channels and details around ticket machines and safety barriers required special attention.

They found evidence that the previous solution was substantially worn, delaminating, and splitting, all of which affected its waterproofing.

The technical team also tested its suggested waterproofing system, Triflex ProPark, by conducting adhesion tests to the underlying concrete which allowed them to determine requirements for the substrate preparation.

Contractors can often apply Triflex solutions directly on top of existing coatings, but in this case the substrate had deteriorated too badly so the team recommended removing the original coating before applying Triflex ProPark. This left the car park exposed to the weather, but as the primer element of the proposed system takes just 25 minutes to become rainproof and the next coat can be applied after just 45 minutes, this was not a problem.

Triflex ProPark incorporates a fully reinforced, elastomeric membrane, certified under EN1504-2 for crack bridging ability to B4.2 (-20°C). This means the contractor, Concrete Repairs Limited (CRL) could apply the waterproofing system confident that it would deal with continued structural movement and associated cracking. Finally, Triflex supplied all the materials for bay delineation and heavy-duty deck signage.

Says CRL, project manager, Gary Dobinson: “Using the Triflex system we could complete an entire area in just a day and manage it to complete smaller areas in phases so that we had no fear of rain affecting our progress. In fact, the time-consuming element of the refurbishment was removing the existing coating before applying Triflex ProPark.

"The system was simple to apply and made it easy to ensure that all the details around ticket machines and bolts holding safety barriers in place are completely waterproofed to avoid any future moisture ingress.”

“We needed a system that would cause minimum disruption to the hospital staff and visitors. The Triflex system allowed us to complete the project within a short time frame.

“Triflex were also very thorough in helping us come up with the right solution, doing a comprehensive site audit with testing to ensure that we had every confidence in the proposed system. This was important because we needed a long-term waterproofing solution that would last for the remaining life of the car park.”

Richard Smith | Project Manager, Skanska.

“Triflex ProPark is easy and fast to apply. It is also fast curing meaning that we are less weather dependent than we would have been with an alternative solution

“It allowed us to apply a complete waterproofing system across the whole car park within the short time frame that we had to complete the project."

Gary Dobinson | Project Manager, Concrete Repairs Ltd.


Case study