The Northernmost of the inhabited Channel Islands, is Alderney.  A spectacular remote island steeped in natural beauty and never-ending stretches of white-gold beaches.

Encircled by the quiet cobblestoned streets of Saint Anne that lead to Alderney’s dramatic coastlines, is The Blonde Hedgehog.

The Blonde Hedgehog, originally a public house, has dramatically been developed into a luxurious gastropub and hotel.  The Blonde Hedgehog is linked to Clarence House and The Corner House, warm and welcoming hotels which offer a deluxe haven to all who stay there.

Delta Registered Installers, Oaks Damp Proofing having previously undertaken work for the client were commissioned to design and install a Cavity Drain Waterproofing system that would meet BS8102:2009 the British Standard for the protection of structures against water from the ground, Grade 3 (no dampness or water penetration acceptable) to the cellar area of The Blonde Hedgehog.

The Cellar having been used historically to store beer was not waterproofed historically.  Beer cellars are notable for being very cold and wet.  For hundreds of years beer cellars were always underground – because underground rooms are generally quite cool.


After undertaking site inspections to the structure, Oaks recommended installation of a Delta Type C Cavity Drainage System.

The cellar area was fully earth retaining and boarders the main road which meant there was a lot of hydrostatic water pressure bearing against the structure.

To reduce risk and slow down the volume of water entering the structure, Oaks treated the walls of the cellar with the Koster KD System.

The main contractor incorporated a new basement slab to the cellar which allowed for incorporation of the Dual V3 Sump Pump and channel recess.  Prior to the installation of the Delta Type C System all new concrete was treated with Koster Polysil TG 500, an anti-lime inhibitor.

Preceding the installation of the Type C Cavity Drainage System, Oaks ensured the waterproofing design would easily be maintainable and repairable.

The benefits of using a Type C Cavity Drainage System enables the management of any water ingress in a controlled process.  Any moisture or running water ingress travels behind the membrane to be diverted to a Delta Submersible Pump allowing for the required Grade 3 environment.

All installed with great dealing and expertise.

Case Study Results

The Blonde Hedgehog’s cellar has been converted from an unused room into a desirable relaxation area for diners and hotel guests.  By incorporating a Delta System, the cellar is completely protected against water ingress along with assurances for the owner, with Delta’s tested product life cycle and installation by Delta Registered Installers that the project easily complies to British Standards.

The customer was absolutely delighted.

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