About Diamond Seal Waterproofing

Diamond Seal Waterproofing is a waterproofing business based in Sydney, NSW. The work covers the areas of a building that have to keep water out: bathrooms, showers, laundries and wet areas internally, balconies, terraces and rooftops externally, and basements, retaining structures and concrete elements below ground.

Waterproofing sits underneath everything else. It is applied, then covered by screed, tiles, pavers, landscaping or backfill, and it is expected to perform for years without being seen again. That reality shapes how each job is approached — substrate preparation, priming, detailing at junctions and penetrations, correct falls, and protection of the membrane before following trades arrive.

We work on new installations and on remedial waterproofing where an existing system has failed. Remedial work always starts with understanding why the original waterproofing stopped doing its job, because a repair that does not address the cause is a repair that gets done twice.

Whether you are a homeowner with a leaking shower, a builder scheduling waterproofing into a construction program, a strata manager coordinating balcony remediation or a commercial property owner dealing with roof or basement ingress, the first step is a conversation about the area and the conditions it faces.