Cavity Drain Waterproofing / Polyurea Bank Side
Introduction
Basement Cavity Drain Waterproofing and Polyprufe.Project: MacLennan were asked to consult on the design of the waterproofing of this very large commercial building. MacLennan were engaged to draw up all of the waterproofing details. There were a great many issues with water penetration into the excavation which MacLennan had to overcome.
The Basement Construction was Secant piling with an inner Reinforced Concrete Lining Wall. The basement extended two levels below ground. The basement will house the Ball Room, gym, swimming pool , Back of House Areas , Plant rooms etc.
The waterproofing was the most critical item in the design and installation. MacLennan supplied design expertise and detailed all aspects of the waterproofing with the Architect , engineer and contractor. MacLennan worked with the design team on all aspects of the waterproofing design.
Methodology
The basement was built of Secant Piling and poured concrete Lining wall. MacLennan installed a full Type C cavity drain system internally.
“Type C – It is accepted that water could enter the building and an internal cavity is provided to depressurise and manage the water.”
Water penetration through the piles and joins was controlled with Resin injection installed by Maclennan specialist resin injection department using a variety of methiods as necessary to prevent ingress of water and silt.
A Cavity Drain Waterproofing Membrane was installed along with base drain and sumps and pumps to complete the waterproofing. In the event of a power failure the system automatically switches to battery power with no loss of
backup pump performance. On resumption of normal power supply the converter switches back to mains
supply and trickle-charges the battery. It all adds up to complete peace of mind.
Polyurea waterproof coating was spray applied to complete the installation.
Result
The basement waterproofing was designed, supplied and installed by MacLennan Waterproofing.
- The system is guaranteed for a period of 20 years.
- The guarantee is covered by MacLennan warranties and 5 million PI.


