Waterproofing: Why it's so important

Did you know that 80% of post-construction building defects are water related?
Story by: Trends
A Horizon Habitats project architecture, building, elevation, facade, home, house, real estate, residential area, siding, window, gray
A Horizon Habitats project

Horizon Habitats is one of Sydney's most reputable builders. They're a small but extremely professional firm that specialises in high quality architecturally designed new homes and alterations and additions, in some of the most prestigious suburbs of Sydney. Here's what they have to say about waterproofing.From Horizon Habitats: Over the past 25 years, architecturally designed homes have evolved drastically. The desire to push boundaries and use minimal, clean lines and finishes has changed not only the way homes look, but also the way they're built. Delivering these new designs takes far more time – both in the planning and the execution.25 years ago, a concrete slab would be poured flat and having a step up in to the bathroom would be accepted as common place. Today, we take an extra day or two to set down the bathrooms in the slab so that once they’re built up in sand and cement, they sit flush with the floor. The set downs are done six months (at least) before any floors are laid, requiring careful foresight and planning.But it’s not just the finishes that are the challenge. The structure also needs careful planning and consideration. Finished floor levels must be understood at the outset, to get flashings and weep holes at the correct levels, as brickwork is usually one of the first trades in the project. Once complete, we must be wary of changes to floor finishes, skylights, and roofs, as they can impact the weatherproofing of a building later on.80% of post-construction building defects are water related – i.e. flashings and membranes. In almost every case (and with 20/20 hindsight) they were avoidable, had the right planning and procedures been followed. The resulting rectification is costly in terms of time and money, as well as stressful and inconvenient to all stakeholders.The design of a holistic waterproofing system of a building is as integral as the design of the slabs, columns, pits, pumps, etc. It is beyond the architect’s scope, but it's also beyond the skill set of even the most accomplished building contractor.Our advice is that we should be engaging an independent waterproofing consultant to be a part of the design process, just like we engage an engineer to ensure the building stands up. Waterproofing consultants should be engaged as early as possible, and retained throughout the build to ensure that their design is in fact implemented and carried out as intended.It is said that a pinch in time saves nine. When it comes to waterproofing, and the costs to fix a faulty detail, that pinch may save nine hundred.


Aug 15, 2017
We know the specialists