New build project in Haverhill, Suffolk.
A concrete podium deck over a basement was leaking and allowing rainwater to penetrate into the structure.
A thin “black jack” type waterproofing system had been used that had a poor crack bridging ability. Hairline cracks in the concrete deck caused the waterproofing layer to split and fail.
In addition the waterproofing had not been dressed up the deck floor junction leaving an easy route for surface water to enter.
The failed existing waterproofing system was removed to allow for a full inspection of the concrete deck.
Smooth rounded fillets were formed at the junctions between the deck and the walls using Koster Repair Mortar Plus.
Koster Deuxan 2c was selected to be the waterproofing system due to its excellent crack bridging qualities up to 2mm when reinforced using Koster Glass Fibre Mesh. This applied across the deck, over the fillets and up the walls to continuous barrier. Koster Deuxan 2c is a cold applied, trowel on system this means that there are no joints or seams which are common areas of waterproofing failure.
The contractor wanted to protect the waterproofing and improve the external drainage. Delta Geodrain Quattro was used to provide protection against impact damage and to speed surface water away into the drainage inlets.