Refurbishment is quite often carried out as reactive maintenance, especially on a roof; and, therefore, speed and cost are usually the biggest influences on product specification.

When replacing traditional bitumen-based surfaces on a roof, for example, a similar product is commonly specified to save on budget, especially for public sector projects such as schools, housing and healthcare.

However, when you consider service life, maintenance costs and the health and safety risks associated with installing a solution that requires hot works – it can often create more issues than it solves.

Sector Under Scrutiny
In a time when any construction or refurbishment project is under close scurrility when it comes to fire health and safety following the Grenfell Tragedy in 2017, special consideration must be paid to the roofing and waterproofing product specification and how it is installed.

It is therefore arguably more important than ever to prioritise safety by considering the alternatives to hot works, not only to protect those in an occupied building, but also to safeguard against costly damage to the building and any subsequent managerial issues.

An Alternative to Hot Works
A cold-applied liquid system can be used as an overlay to existing waterproofing, with no strip-out required which offers a fast alternative to bitumen-based systems, whilst minimising disruption and avoiding the risk of fire.

When an upgrade to the building’s thermal performance is required, a fully cold-applied insulated roofing solution can be also specified as an alternative to a hot works-based system.
Cold-applied liquid applied membranes are seamless and fully bond to the substrate making them ideal for use over waterproofing systems that are coming to the end of their design lives.

Quick and easy to apply, and with solvent-free options available, liquid roofing and waterproofing solutions can minimise disruption to any project, especially those within occupied buildings.

Trusted liquid manufacturers, with the appropriate product certification, can offer a service life of up to 25-years for some liquid solutions. With quick an easy installation, excellent performance and extended service life, alongside with zero fire risk, it’s easy to see why specifying this alternative to a hot works-based system not only improves the health and safety on site, but also makes sound business sense.

Whichever liquid waterproofing solution is specified, it is always advisable to opt for an experienced, well established liquid manufacturer with full system training, specialised on and off-site support, and system warranties to ensure a sound waterproofing solution for many years.

Public Sector example: St John’s and St Elizabeth (HJE) Hospital
Kemper System’s cold-applied liquid waterproofing solution has been specified for a multi-million-pound extension at St John’s and St Elizabeth (HJE) Hospital in the St John’s Wood area of London.

The £35m new build development has created six, hi-tech theatres and a day case suite which is one of the most modern in the UK. The extension also includes a new admissions lounge, imaging department, consultant rooms and an expanded Urgent Care Clinic.

A total of 9,060sqm of Kemper System’s Kemperol 2K-PUR solvent-free and odourless waterproofing membrane has been applied beneath the building’s green roof, onto a pedestrian trafficked walkway, the lower roof area and a plant roof area. The cold-applied solution was installed by London-based Ridgewell Flat Roofing Ltd.

Contractors had a strict timescale to adhere to, meaning a quick and easy application solution was required to complete the job.

Because of the location of the new build extension, adjacent to an occupied hospital building at HJE, the solvent-free and odourless qualities of the Kemperol system meant minimum disruption at the hospital throughout the application process. No hot works were required as part of the project, further reducing potential health and safety risks, and meaning no wait times were needed between applications of resin.

Once cured, the system forms a seamless, elastomeric waterproof membrane that cannot delaminate, is UV stable, and creates a sturdy bond directly to the substrate.

Additionally, the plant roof area had a number of complexities with many ventilation outlets and air conditioning units, and because Kemper’s waterproofing system is roller-applied, operatives could easily install the resin underneath the units and around the complex roof structure.

Our Kemperol 2K-PUR solution is manufactured using an 80 per cent castor-oil formula derived from sustainable sources. The system has a proven 20-year track record and continues to be one of the most popular and sought-after systems for many public sector projects.

Ben Ridgewell, managing director of Ridgewell Flat Roofing, said: “We have used Kemper System for many years, and the cold-applied solution was perfect for this prestigious project because it is so versatile. We could apply the system to each of the different roof and walkway areas with ease without having to switch roofing materials.

“Kemper System once again delivered on such a complex project, which presented winter working challenges, specifically with high winds at times. Large expanses of sheeting material would have not have been practical or safe on site, so a roller-applied liquid waterproofing solution was the best for this project. We were extremely happy with the results, and so is the end client.”

St John & St Elizabeth Hospital, which is in its 165th year of operation, is an independent charitable hospital. All treatments that take place in the hospital help fund the on-site St John’s Hospice, which provides free palliative care to more than 4,500 people and their families each year, across seven boroughs. The hospital provides surgery, medical care, outpatient, and diagnostic services for children, young people, and adults.