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Bostik provides caring touch on St Ann’s Hospital project

Bostik provides caring touch on St Ann’s Hospital project
Subfloor preparation
St Ann’s Hospital, Tottenham

The redevelopment of St Ann’s Hospital, a multipurpose healthcare campus in Tottenham, included a new, purpose-built mental health inpatient building. Designed to transform the care of patients and the working conditions of staff, the 74-bed mental health facility involved an extensive redevelopment of the previous wards on the site and is rated BREEAM Excellent.

Bedford-based flooring contractor, Blade Flooring, was appointed to install the floor coverings throughout the redevelopment, and turned to trusted supplier Bostik for its technical specifications and subfloor preparation products.


The project was large and varied, with the subfloors in the unit’s three blocks having different requirements that needed to be treated in unique ways.

For example, some parts of the subfloor were made of concrete and others were made of plywood. For the concrete areas, the Bostik team advised that Blade Flooring apply its HYTEC E570 ONE COAT damp-proof membrane (DPM) to suppress the residual moisture in the subfloor, followed by GRIP A526 UNIVERSAL PRIMER and SCREEDMASTER SL C540 FLOW smoothing compound, which provides improved workability and excellent flow characteristics.

For the plywood areas, once they had been primed, Bostik specified SCREEDMASTER SL C530 FLEX, a fibre-reinforced, heavy-duty smoothing compound that is particularly suited for application onto wooden floors.

This varied approach continued into Blocks G and H where, again, some parts of the subfloor were concrete and others were plywood. In this case, however, there were a number of hydration cracks in the surface of the concrete. These were overcome quickly with Bostik RENO P520 EASY, a crack repair system including a solvent-free, 2K repair resin and stitching pins. RENO P520 EASY can be mixed easily within its containers and dries in just 30 minutes.

“There were a number of hydration cracks in the surface of the concrete”

Once the cracks had been filled in, the team primed the surface with GRIP A936 XPRESS, Bostik’s water-based primer with high grip and a fast drying time, before smoothing it with SCREEDMASTER SL C530 FLEX.

Block B required yet another approach, as there was Lytag screed present in parts of the subfloor. In some areas, this could be worked around, while in others it was so damaged that it needed to be removed. In the areas where a new screed was required, Bostik advised Blade Flooring to apply a slurry mix of TECHNIS C720 FLOW – a pre-blended, rapid fluid screed, mixed with Bostik SBR – a co-polymer latex that toughens, waterproofs, and improves the chemical and abrasion resistance of screeds. Once the slurry mix was applied to the prepared substrate, TECHNIS C720 FLOW was again used to reinstate the levels where the Lytag screed had been removed. Once applied, TECHNIS C720 FLOW can receive moisture sensitive floor coverings in as little as 7 days. This product, with its rapid drying performance, helped to keep the programme on-track.

The team then primed the surface with GRIP A936 XPRESS, before a layer of SCREEDMASTER SL C540 FLOW was applied to smooth the subfloor ready for the adhesive and floor coverings.


Bostik’s technical advice and subfloor preparation products enabled Blade Flooring to navigate a complex and demanding installation, ensuring they could install the floor coverings to the highest standard, on time for the hospital to open its doors to patients.

James Hall, Business Development Director at Blade Flooring, adds: “This was a demanding project with many challenges due to the sheer size of the building as well as its age.

“On a project like this, the technical and specification expertise of a company like Bostik is invaluable. You are inevitably going to face challenges on such an old site, but with Bostik’s experience and products, we were able to meet these challenges and install the flooring on time and to the right quality.

“On a project like this, the technical and specification expertise of a company like Bostik is invaluable” – James Hall, Blade Flooring

“The Bostik team made multiple visits to the site during the process, depending on which part of the building we were working on at that time. They always came whenever they were needed, and we relied on their advice at every step.

“Not only was their advice spot on, but the products they specified for us all performed excellently, each one doing exactly the job required of it. I would highly recommend Bostik for all flooring projects.”

The new mental health facility is part of a project to create a modern health campus with direct benefits to the local community. With a sustainable mix of mental health and other services, the St Ann’s Hospital site includes services provided by Moorfields Eye Hospital, Whittington Health community health services, and North Middlesex University Hospital breast screening services. In the next phase of the development, homes for the local community and an open space for the public will also be created.