Waterproofing a Newbuild Housing Development, Cheshire
Reinforced concrete basement structure for development of a series of townhouses
Tanked externally with liquid applied bitumen rubber waterproofing (Type A Tanking)
Waterbars instaled in construction joints within the reinforced concrete structure (Type B Integral waterproofing)
Press fit gaskets effectively seal vulnerable service penetrations
Internal cavity drainage waterproofing installed to create and maintain a warm dry habitable space (Type C waterproofing)
External podium deck across front of property treated with traffickable polyurea deck waterproofing
There was no problem! This was a steady project for Trace with proven solutions implemented to address the various requirements for different types of structural waterproofing systems which this scheme implied.
As per the above, we included a number of systems to protect the basement and deck structures. The concrete retaining walls received an external liquid applied system, this being an elastic bitumen rubber, radon and BDA certified tanking membrane, applied in two coats to provide a barrier to exclude water.
Construction joints in the reinforced concrete, formed where new concrete is poured against cured concrete, recieved a hydrophilic polymer based waterbar. These expand upon coming into contact with water, forming a compression seal within the confines of the construction joint.
To provide redundancy against any ingress through the retaining structure, and to allow formation of a guaranteed warm dry space internally, we then installed internal cavity drainage. This system comprises studded vapour barrier membranes installed to the retaining walls and across the floor, with a series of drainage channels installed beneath the membrane. Any minimal ingress is collected and discharged, in this case by gravity to low ground externally.
The proeprties also include a skylight lantern detail to the front, which brings natural light into the living space below. This resulted in an area of deck / buried roof, which received paved finishes. The structure here was concrete laid to falls, this received an epoxy primer, followed by an application of polyurea, which is a hot spray applied plastic, which cures almost instantly upon application. This was over-laid with a drainage layer membrane, before receiving finishes over.
The external wall (above ground) adjoining the deck was specified by Trace to receive a lead cavity tray detail, i.e. it was a robust tray detail - water bypassing the tray would otherwise drip onto the basement ceiling beneath.