Product / system manufacture
Product / system supply
Main contractor: D J Hutchings Ltd; Sub-contractor: Peter Cox Ltd.
Delta range: MS500 wall membrane, MS20 floor membrane, Dual V3 sump pump, Geo Drain Quattro; Köster range: NB1 waterproofing slurry, Repair Mortar Plus, Quellband hydrophilic waterbar, and Deuxan 2C.
A range of Delta waterproofing products was used at ground level on a semi-detached property in Hertfordshire that suffered from severe flooding. Although primarily designed to waterproof basements, this is not the first contract where the Delta system has been selected for 'flood recovery', with application benefits such as economy and speed of installation in such critical situations.
Restoration experts DJ Hutchings of Towcester and sub-contractor Peter Cox Ltd to carry out the survey, which showed that flood water had caused substantial damage internally. Delta technical experts were consulted for an installation solution.
Work includes the full strip-out of all wall finishes and the solid floor on the ground floor. Mass underpinning is to take place to all the external walls. Delta MS500, an 8mm studded membrane, will be applied to all ground floor walls to create a drainage path allowing up to 135 litres/min/metre of incoming water, well in excess of demand.
The new floor slab will incorporate Delta MS20, an HDPE membrane with 20mm studs, with a compressive strength rating of 150kN/m2 and high-capacity drainage.
In line with BS8102:2009, a network of serviceable 100mm underground pipes is laid throughout the oversite and turned up 90° through the new concrete slab. These are protected by a Delta puddle flange and cut off level with the slab positioned at 12m2 centres. This aids for fast collection of groundwater that was rising through the slab due to the high water table.
The pipe network is connected to two Delta Dual V3 sump pumps, which can evacuate any groundwater at 8 litres/s. Delta AlertMaxx high level alarms will also be installed.
Köster NB1, an ‘active’ crystalline slurry, will be applied between the underpinning stalls or interfaces to create a watertight seal. Köster Repair Mortar Plus will also be applied at the areas where the walls meet the floors to act as a first line of defence. Köster Quellband hydrophilic waterbar between the slab and the wall underpin junction forms a watertight seal.
A positive approach has also been adopted with the use of Koster Deuxan 2C on the structure exterior. This is a two-coat polymer modified fully bonded material applied to the underpins and backed up by Delta Geo drain Quattro drainage and protection layer.
The range of products from Delta Membrane Systems is well known to contractors involved with the renovation of damp, dingy basements, and to those creating basement areas in new-build products.
Using the products for the refurbishment of areas adversely affected by flooding is not new to Delta, and the company sees this as being a market sector that would really benefit in terms of time and cost.