Combined Waterproofing System – Type A (Barrier) Protection and Type C: Drained Protection

HomeCombined Waterproofing System – Type A (Barrier) Protection and Type C: Drained ProtectionCombined Waterproofing System – Type A (Barrier) Protection and Type C: Drained Protection

We attended a private house in Leicestershire to waterproof a new extension.  This project falls in line with the regulations for waterproofing dwellings with earth-retaining walls as set out in NHBC Chapter 5.4.

Before our arrival on site, the main contractor built a R/C subfloor and a bund along the full length of the retaining walls.

Combined waterproofing:

Internal: Type A (Barrier) Protection

We applied a Type A waterproofing ‘barrier’ system to the internal block work structure.

  1. We treated the blockwork with a lime inhibitor to limit the leaching of free-lime from the structure.
  2. We installed fillet seals at the base of the bund using repair mortar. The use of fillet seals helps to ensure a smooth transition between horizontal and vertical surfaces.  As a result this will reduce the risk of leaving gaps or holes unsealed during the waterproofing works.
  3. We then applied two coats of Newton Hydrocoat 105 1K tanking slurry waterproof membrane to the internal surfaces.

Internal: Type C (Drained) Protection


The effectiveness of this system is dependent upon discharging free water before pressure can build up.  In this case gravity drainage was installed.

Access/Flushing points:

We installed these at key periodic locations around the perimeter channel system to enable the system to be maintainable in accordance with requirements stipulated in BS 8102 2022

Wall Cavity Drain Membranes:

Walls:   We fixed 8mm cavity drain membrane to the earth retaining walls, floor to DPC.

Our client sent us this feedback:

Yes extremely happy with the job and I would also just like to mention that how professional and prompt yourself and Carl have been and I would definitely use and recommend Damptec for any future projects if needed.” att


By selecting Damptec for your extension waterproofing requirements in Leicestershire, you guarantee a professionally managed project with dependable and durable waterproofing solutions.

Contact us today for more information and to discuss your project requirements.

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