Queensland Public Hospital
Two leaking concrete tanks are part of the main supply of water for the fire sprinkling system throughout the hospital, with a capacity to hold 354,000 litres.
- Property Type: QLD Public Hospital
- Contractor/Applicator: Waterstop Solutions
- Testing of existing and renewed membrane: International Leak Detection Australia (ILD)
Category: Membrane Renewal
Product Used: Specialised bitumen modified highly flexible waterproofing membrane. Installed in multiple layers to a moisture barrier primer system.
- Compatible with the existing membrane
- Highly flexible
- Effective barrier against waterborne salts
- Resistant to atmospheric gases
- Compliant to Australian Standards for potable water (AS4020)
- Supported by manufacturer’s warranty for 10 years, which is extendable to a further 10 years with a maintenance application
The existing membrane was a liquid membrane, on which several repair attempts by other service providers had proven to be futile with recurrent poor membrane adhesion to the substrate in a number of places, which in turn was causing multiple continuous leaks from these two concrete water tanks.
Challenge number 1
Identification and mapping of all possible leaks
The tanks were leaking from many places, and it was imperative that the remedial waterproofing was 100% watertight. The recurrent challenges were that the waterproofing membrane did not adhere to the substrate in a number of places, which was causing multiple leaks across the two tanks. To ensure that all possible breaches of the membrane were properly identified, Roberto Scalpelli and his team from International Leak Detection (ILD) Australia were brought in to identify where all the breaches in the membrane were. At the completion of the installation of the new waterproofing membrane, ILD Australia was brought in again to inspect and test the new membrane.
Challenge number 2
Downtime, Noise Restrictions and Costs
A full removal of the existing membrane and refurbishment of the water tanks was beyond the bounds of possibility. This approach would have attracted massive costs and a prolonged downtime of empty fire tanks. There were also noise restrictions to take into consideration around hospital patients and staff. The applicator partnered up with suppliers and their network to combine their technical skills. the market was scoured for a compatible product that could work with the existing membrane and that would be fully supported by the manufacturer’s full warranty. Product supply partners were involved with the testing and checking quality of the contractor’s developed application prior to the start of the works. They also supervised quality testing throughout the duration of the works carried out.
The Remedial Waterproofing Solution
Thorough surface preparation and vigilant detailing of all penetration and junctions is key to successful remedial waterproofing. A specialised bitumen modified highly flexible membrane that is compatible with the existing membrane was installed in multiple layers to a moisture barrier primer system. The primer system assists with preventing bubbling or blistering, which is highly likely in remedial waterproofing, if not performed.