
Case Study / Waterproofing
New Build Basement, Winchester
Design, Supply & Install. MacLennan take the risk out of Waterproofing

Winchester based quantity surveyors Quadridgy, approached MacLennan to assist with designing, supplying, and installing suitable waterproofing to a new build property with a basement in the stunning, remote Winchester countryside.
The contractors constructed the basement using Secant Piling method. Basement walls must be able to support the load placed upon them, and one way to ensure this is with the use of reinforced concrete walls.




Method
MacLennan were involved with this project from the design stage so that the basement could be designed to incorporate the suitable waterproofing. As this property will be a habitable environment, which is defined as a Grade 3 environment in BS8102/2022, any water ingress would be unacceptable and therefore two forms of waterproofing should be considered. MacLennan specified that Type A and Type C waterproofing should be used as the best solution for this project based on all the information provided.
Type A waterproofing consists of spraying a crystalline coating as the first form of protection. This would be spray applied to the retaining and ground bearing concrete wall and slab areas.
The second and most important form of protection is in the form of a Type C Cavity Drain system which comprises of Cavity Drain Membranes, Drainage, Pumps and Control Systems. It is also a very economical solution which MacLennan can fully guarantee. The System-08 ventilated cavity membrane was fixed from floor to ceiling, the Hydrodrain channel was installed around the wall floor join, with Wall Mounted inspection ports making it easy to service the system.
A small deck area in the porch above the basement also needed to have waterproof protection applied. MacLennan’s specialist technicians prepared the surface of the deck area to remove any surface laitance, a primer was then applied and allowed to dry before using the Polyprufe spray. This protection provides a continuous membrane which resists weathering, has excellent adhesion and is completely designed and guaranteed by MacLennan.
Result
MacLennan completed all works within the time frame and the budget. The Polyprufe system is guaranteed for 10 years.
All of this work was backed by MacLennan’s full installation guarantee and PI cover on the design.
