Nudura Insulated Concrete Formwork (ICF) was chosen both above and below ground in the construction of this traditional two-storey farmhouse in Yorkshire.
The property sits on a natural gentle slope with a basement fully buried to the rear and a raised patio area to the front.
Using a number of Triton waterproofing products, the lower slab to the farmhouse was made waterproof by the installation of a membrane beneath it and inclusion of an additive in the mix.
This waterproofing agent contains active chemicals that react with fresh concrete to generate a non-soluble crystalline formation, sealing the concrete against the penetration of water.
A pre-formed water bar, which swells when in contact with water was placed into all joints. The shuttering around the slab had made provision for the concrete groove in the face of slab and the bar was fixed into the groove using a mastic expansion sealant.
The bar was also placed in the centre of the wall on top of the slab protecting the joint between the wall and the slab. The walls were filled in one day, with over 60m³ of concrete.
All joints between the polystyrene panels were protected with reinforcing fabric to give extra tensile strength. A fillet seal trowelled into a wedge shape to the external toe of the concrete slab ensures that any water flows away from the joint which was also protected with the fleeceband.
Externally, the basement walls were treated with two coats of vapour membrane providing a primary waterproof and gas proof barrier.
The membrane layer provided drainage and protection working as a traditional cavity drain membrane to allow air movement between its face and the formwork. The geotextile layer of the membrane was then extended over the land drain and the external walls were then back filled.