Delta supply flood recovery system to Grade II listed building

Delta Membranes has supplied a flood recovery system to a Grade II listed property in Long Marston following a bout of flooding. Specified by surveyor Peter Cox, the solution allows for fast reoccupation in the event of a repeat incident.

The installation of the Delta system involved the full strip-out of the building’s wall finishes and the solid floor on the ground level, with mass underpinning taking place to all the external walls.

Internal system

The solution comprises Delta Membrane Systems’ MS500 range: an 8mm studded polyethylene membrane which will be applied to all ground level walls, creating a drainage path that will allow 135 litres/minute/metre of incoming water to be drained. 

The replacement floor slab on the ground level will incorporate an hdpe membrane called Delta MS20. The membrane features 20mm studs that provide a compressive strength rating of 150kN/m2 in addition to high capacity drainage.

A network of serviceable 100mm underground pipes, protected by a Delta puddle flange, have been laid throughout the oversite and turned up 90 degrees through the concrete slab, cut off level with the slab positioned at 12m² centres. This aids the fast collection of groundwater that was rising up through the slab due to the high water table.

The pipes are connected to two Delta Dual V3 Sump Pumps, which evacuate the groundwater at a rate of 8 litres per second. Two battery back-up systems will be installed with the new Delta AlertMaxx alarms.

Delta also supplied the Köster NB1 ‘active’ crystalline slurry, which will be used and applied between the underpinning stalls and interfaces to create a watertight seal between the joints. 

It will be applied along with Köster Repair Mortar Plus to areas where the walls meet the floors to act as a first line of defence. Köster Quellband hydrophilic waterbar has also been fitted between the slab and the wall underpin junction.

External system

To complete the system, Delta used the Köster Deuxan 2C externally, a two-coat polymer modified fully bonded material applied to the underpins backed up by Delta Geo drain Quattro drainage and protection layer.

Delta Membrane Systems,
Delta House,
Merlin Way,
North Weald,
Epping,
Essex,
CM16 6HR
United Kingdom

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