Newbuild Basement, Richmond – Combined Basement Waterproofing Protection Using Vandex and Oldroyd

Background

The Greyfriars Extra Care Housing Scheme is a partnership between Housing 21, North Yorkshire Council, Richmondshire District Council, and main contractors Frank Haslam Milan (FHM). The development overlooks the medieval town of Richmond, North Yorkshire and consists of 39 two-bedroom apartments for older people with a range of care and support needs.

The Basement

The development is built into a hillside and has a 1500 m² basement area formed using contiguous piling. A decision was made to appoint a specialist contractor, Brick-Tie Preservation, to provide an effective and guaranteed basement waterproofing solution.

Basement Waterproofing

In conjunction with Safeguard, Bryan Hindle of Brick-Tie Preservation designed a combination waterproofing system to BS 8102 for the basement area. The waterproofing system incorporated Type A (barrier protection) and Type C (drained protection) elements.

Waterproofing the Basement Floor Slab

Vandex Super crystalline active waterproofing slurry (Type A BS 8102) was chosen as the waterproofing solution for the 1500 m² basement floor slab due to it’s proven waterproofing capabilities and cost effectiveness.

The slab was prepared using enclosed shot blasting to remove any laitance before application of the Vandex Super waterproofing slurry. The treated slab was protected from rain and traffic during the curing period using polythene sheeting.

Cavity Drainage (Walls)

An Oldroyd Xv Clear cavity drainage system (Type C BS 8102) was chosen as the waterproofing solution for the basement retaining walls. A land drain was laid around the perimeter of the basement in front of the retaining walls. A blockwork wall was then built in front of the contiguous-piled retaining walls.

Oldroyd Aquadrain drainage channel was laid around the perimeter of the basement at the junction between the slab and the blockwork wall – incorporating flushing and inspection eyes. Oldroyd Xv cavity drain membrane was then fixed to the blockwork wall using sealed fixing plugs.

Any water seeping through the blockwork wall will therefore be directed into the Aquadrain channel. Because the basement was built on a sloping site it was open on one side allowing the Aquadrain channel to discharge by gravity rather than requiring a powered sump and pump.

Joints and Overlaps

Vandex Construction Joint tape, Vandex BB75 E, And Vandex Uniflex were used in areas where the two waterproofing systems joined or overlapped – ensuring that the system could work as a whole.

Basement Waterproofing Guarantee

The contract has now been signed off by Brick Tie and a 20-year GPI guarantee issued for the work.