Waterproofing specialists seal leaky basement


Waterproofing and damp proofing specialists, Severn Damp & Timber Preservation, installed a range of Triton Systems’ waterproofing materials to deal with water ingress around two skylights, formed within the concrete roof deck over a basement that extended into the garden of a domestic property.

The RC walls and floor slab of the basement were originally waterproofed using a bentonite membrane, whilst the concrete roof deck was protected with a self-adhesive sheet membrane.

Following the report of visible signs of water ingress into the basement, including staining to plasterwork from the two skylights, Severn Damp’s MD, Billy Roberts, with the support of the Triton technical team, designed a waterproofing solution to seal around them and to encourage surface water to drain away. He then recommended future works to lay gravel back over the deck or to make a green roof.

The gravel was removed around the skylights and the exposed brittle and cracking plastic damp proof membrane was cut back. The area was then jet washed. Mortar incorporating Triton Trimix Resin, a water and salt resistant additive, was then injected around the skylights to fill any gaps. A bottle cove fillet of Triton Fillet Seal was then applied around the skylights and coated with two coats of Triton TT55 extending over the deck to one metre around each.

Triton Fillet Seal is a pre-packed cement based and polymer modified product, designed for use as a floor to wall junction seal during waterproofing works. It helps ensure a smooth transition between horizontal and vertical surfaces and minimises the risk of leaving gaps or holes unsealed. Triton TT55 is a highly effective damp proof ‘tanking’ membrane, applied as a slurry to brickwork, concrete or any cementitious substrate.

A screed, incorporating Triton SBR latex admix (to improve the durability and water impermeability of the mix) was then applied around the skylights and across the whole deck area, with falls laid to prevent standing water.

Finally, two coats of Triton TWS Fastcoat were applied (over a primer coat) followed by Platon Double Drain protection and drainage membrane installed over the coated areas.

TWS Fastcoat is a single pack, moisture curing polyurethane elastomeric resin. It cures as a fully bonded and seamless layer, offering continuous and flexible protection, capable of withstanding minor building movements without cracking.

Platon Double Drain drainage and protection cavity membrane is used externally against retaining walls and across podium decks. In this application it protected the TWS Fastcoat layer from potential damage and maintained a clear space through which the water could drain freely.