Delta Registered Installers, Timberwise were called upon to provide a waterproofing solution to a large detached, luxurious new build property in Birmingham.  The impressive, basement extension, was designed to house a cinema room, gym, and wine cellar.

The scope of the project was to facilitate a waterproofing solution for a substantial brick built detached property with a large 3 elevation basement situated at the bottom of a steep sloping driveway.  The basement when constructed had 1 form of external waterproofing incorporated during the build stage, however the system required a second form of internal waterproofing due to the location of the structure and high-water table, capable of protecting the luxurious basement from unwanted water ingress.

The property’s driveway significantly slopes from street level to the front elevation of the property requiring a specialist waterproofing system to protect the structure.

Working in conjunction with the homeowner, Timberwise’s CSSW qualified waterproofing surveyors specified a Delta Type C (Drained) Protection waterproofing system to provide the necessary Grade 3 (habitable environment) to enable to homeowner to fully utilise their basement space.  For Grade 3 habitable environments, two types of waterproofing may be required.

A Waterproofing Designer’s philosophy defines what they wish to accomplish in the design of their waterproofing system and which principles they will use to do so.  Identifying a robust and suitable design philosophy is an important aspect when designing a continuous system, as this will not only directly impact in how users install the system but also in future maintenance which will directly impact on the property owner.


Before specifying a robust waterproofing solution, Timberwise attended site to undertake surveys on the property, these detailed studies were carried out to supplement and verify the site information provided by the client, focusing on specific site issues.

Ensuring that the project was fully compliant with BS 8102:2009 (Code of practice for protection of below ground structures against water from the ground) and Approved Documents, Timberwise recommended combining a secondary Type C internal cavity drain membrane system to the already constructed external waterproofing system.

The Delta Type C internal cavity drainage membrane system is a reliable and completely maintainable waterproofing solution.  Prior to the installation of the Delta Type C system, all weak points within the internal structure were identified and treated.  Coved fillets were incorporated to the all-important wall/floor junctions to ensure any moisture or running water which will travel behind the membranes in a controlled drainage system will not seep into the structure at these potential weak points.

Delta MS 500 was securely fixed to the internal walls of the basement using Delta’s specialist fixing plugs, with Delta MS20 installed to floors.

Timberwise opted to incorporate Delta’s Glass range of insulation to ensure the entire system was compatible.

Below the floor membrane perimeter drainage channels were sited within rebates allowing for suitable drainage of any future water ingress and being diverted to suitable discharge points.

After the Type C System was installed the all-important integrity testing was undertaken to exercise the waterproofing system in worst case scenario.

Case Study Results

As a particularly experienced Delta Registered Installer, Timberwise were able to confidently recommend, design and install a comprehensive waterproofing system that will protect the property from unwanted water ingress for the life cycle of the structure.

As quoted by Timberwise’s CSSW qualified surveyor “We know we get quality, and the products work seamlessly with each other, and we fully understand what is required of us as an installer to provide the client with a quality installation.”

The homeowner was delighted with Timberwise’s due diligence and their ability to share their expertise and explain the install process on a regular basis.

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