EVERYTHING YOU NEED TO KNOW ABOUT THRESHOLD DRAINAGE

Developed in the 1990s as a requirement for special needs access, threshold drains have evolved as mainstay of sleek, contemporary and organic home design. Owing to their level-plane design, threshold drains provide a seamless connection between indoor and outdoor living areas, thereby eliminating the 'trip and wheelchair' hazard of stepdown partitions. Threshold’s smooth integration into the door track not only delivers unimpeded access for mobility-impaired occupants (including those with wheelchairs or walkers), but creates exquisite continuity between indoor and outdoor environments – an emerging trend in today’s ‘bring the outdoors in’ design movement.

How Does Level Threshold Drainage Work?

The threshold drain consists of an external linear grate which sits beside the doortrack. An integrated, concealed, sub-sill collects water and condensation around the doorway and conveys it to the external drainage system.

The streamlined design creates a disguised water barrier between indoor/outdoor living areas. This removes ‘trip- and-slip’ hazards – such as stepdowns and high gradient falls – that historically existed across doorways with rolling, sliding and bi-fold doors.

Is Threshold Right for Your Drainage Needs?

Poor surface drainage is a persistent problem for architects and builders. Property owners know that prolonged water exposure (or 'ponding') can result in property damage. While traditional stepdown doorways merely repel water from indoor surfaces, a quality threshold drain acts as both barrier and active water conduit, providing superior drainage around the doorsill area. So could threshold offer the best solution for your unique drainage fit-out?

These Three Key Benefits and Considerations will help guide you in making the right decision:

1. Equitable Access Design.

The threshold’s ingenious level-plane design overcomes a major obstacle for universal doorway access: step-barrier water containment. By integrating drains into the door-track, threshold provides an unbroken path between internal and external surfaces, allowing uninhibited movement between the doorway.

2. Is Your Threshold Waterproof Compliant?

Due to its proximity to indoor areas, any breach of the sub-sill could see water penetrate wall and floor finishes, causing extensive damage to moisture-sensitive materials and structural foundations.

It is therefore imperative that your threshold solution can guarantee adequate waterproofing as well as structural integrity. To ensure you meet the highest standards of Australia’s Waterproofing code, make certain your threshold drain:

• is manufactured with 316 marine grade (corrosion-resistant) stainless steel that withstands high water flows, harsh chemicals and suspended solids.
• can resist shrinkage and expansion of substrate materials, framing and finishes, and temperature variations from -5°C to +50°C.
• your substrate area is supported by waterproof membranes that meet strict requirements of AS/NZS 4858 (Wet Area Membranes).

3. ‘Bring the Outdoors in’: Threshold as a Style Choice

The increasing popularity of open-plan living is dissolving the traditional barriers between indoor and outdoor spaces. In the push to harmonise these once discrete environments, designers must find creative ways to integrate practical building elements seamlessly into the design fabric.

Threshold’s narrow-profile stainless steel design marries the traditional with the contemporary, and is versatile enough to meet any doorway shape.

Key Considerations for Your Threshold Drainage Project

Specifically designed to straddle the water-sensitive divide between the indoor and outdoor spaces, threshold drains deliver superior level-plane drainage beside the doorframe; a concealed, low-profile construction is not only a stunning visual statement, but a highly practical design feature, delivering universal access provisions for mobility impaired occupants.

The Threshold solution is an impeccable option for any open air design. It is crucial for designers to recognise the unique architectural and building requirements of threshold designs to achieve the maximum results with their installation. Here are the Key Considerations for Your Threshold Drainage Project:

1. Flow Rates

Most linear drains are designed to convey up to 40 litres of water per minute. Designers should thus be mindful of the incidence and frequency of heavy local downpours (or shower flow rates in bathroom applications), localised flooding events, and the risk of potential overflow.

2. Timber or Metal Threshold

Doorway thresholds are installed beneath the door to help reinforce the doorframe. Door thresholds come in either wood or metal variants, each with distinct advantages: while wood offers a more versatile and cost-effective base for threshold drainage, it is susceptible to rot; metal (typically aluminium) thresholds present a more costly and less versatile option than timber frames, but are far less vulnerable to wear-and-tear stresses.

Due to the unique properties of each door threshold material, separate waterproofing provisions exist for each system.

Superior Quality Meets Sophisticated Design: The Stormtech Solution

Stormtech remains at the forefront of threshold drainage innovations and sleek contemporary designs. Stormtech was directly involved in the development of Australia’s Waterproofing standards (AS-3740 & AS-4654) and continues to work closely with certifiers, architects and inspectors to ensure their threshold solutions are of the highest quality and fitted for purpose. With an unrivalled range of grates, doortracks and subsill configurations, Stormtech can help tailor a customised threshold solution for your unique drainage project.