Dry Waterproofing Ltd were contacted by Mr Martyn Grant of PBA Structural Consulting Ltd to provide a solution for dealing with the flooding problem that was affecting the bathroom and utility room within the basement of this typical Victorian house. The house had been converted into flats by the property owner, and as part of this conversion work the basement floor was lowered to obtain more headroom.
The walls were also underpinned and waterproofed (tanked) with a cementitious render during the process. They informed us that the flooding problem came about following repairs to a bust/leaking soil pipe that was concealed in the base of an earth retaining (tanked) wall. This was caused by a blockage in the street sewer/pipe network. Gaining access to the concealed pipe compromised the existing waterproofing system and thereby allowed ground water to enter the structure.
Once all the fixtures and fitting had been removed to facilitate the waterproofing works, a sump hole was dug in the floor for the Newton pumping system. Channels were also cut into the floor around the base of all walls ready for installation of the Newton pre-formed perimeter drainage channel (BaseDrain). The floor surface and base of walls were treated with Newton lime scale inhibitor to prevent/reduce lime scale forming.
Newton 508 (8mm studded) cavity drain membrane was then mechanically fixed to the walls with the Newton multi-plugs using the ‘curtain wall’ hanging method. This method of installation requires less fixings when the walls are being independently dry lined with a ‘fast track’ metal stud or timber batted dry lining system in front.
The Newton pumping system was then installed. This consisted of a pre-formed sump liner, two submersible pumps, a battery back-up facility and a pumps control panel with a high water level alarm, together with the Newton perimeter drainage channel (BaseDrain) incorporating jetting ports which were linked to the sump and pump chamber. Finally, because of the limited headroom, Newton 603 mesh membrane was bonded to the concrete floor slab using an elastomeric cementitious bonding compound and the membrane was sealed to walls and around the sump chamber with Newton preparatory sealing ropes/tapes/overtape and left ready for the client’s builder to lay floor tiles directly on top of the floor membrane.
A fast track sympathetic approach of dealing with an age old problem of waterproofing structures below ground was achieved quickly. This enabled the client’s builder to install fixtures and fitting to the independent dry lining system without fear of compromising the waterproofing and was much faster than traditional cementitious waterproof (tanking) systems.
The owner of the property needed to have the basement back in habitable use quickly so they could to let the flat to tenants as soon as possible. The installation of the Newton membrane system achieved this with benefit of a long term meaningful guarantees, which is insurance backed.