How Does Outdoor Pedestal Flooring Drainage Work?


Outdoor structures are exposed to the natural elements, so water damage can occur if drainage is inadequate or the wrong waterproofing methods are used.

Traditional drainage involves sloping the floor so that water flows into a central drain and applying a waterproof layer beneath to prevent water seeping into the substrate.

The problem is that sloping floors can present structural challenges when building which in turn can compromise the integrity of your waterproofing, requiring a costly reapplication of the membrane.

While a pedestal flooring system will not prevent membrane failure, it can significantly extend its life-span. That’s because air circulates in the void between the floor and the laying surface, helping to prevent dampness and protecting the membrane from UV deterioration.

It also does away with the need for a sloping floor, because the pedestals can be adjusted to compensate for a drainage slope in the substrate. The result is a perfectly level floor with small gaps between each slab or tile that allow water to discharge onto the laying surface and drain away.

There are several scenarios where outdoor drainage is assisted by pedestal flooring

Balcony drainage

Poorly conceived balconies are constructed with minimal drainage slopes, making them susceptible to moisture build up between the floor and the membrane. Failure of the membrane in such circumstances can have devastating structural consequences, so the inclusion of a pedestal flooring solution to a balcony in the design phase ensures the stability and integrity of the structure for a long-term investment.    

Timber deck drainage

Drainage is also important for timber decks, as standing water beneath can lead to a reduced lifespan of the decking and substrate. Preparing the ground with suitable drainage materials such as gravel and ag pipe and installing a pedestal flooring solution will create a perfectly level deck with excellent drainage.  

Draining sloping surfaces

Gradient determines drainage on sloping surfaces (paving needs 1%, turf needs 2%). Good drainage can be achieved by correctly grading the slope and installing pipes at the base to carry water away. Installing a pedestal flooring system can then ensure a perfectly level floor, as each pedestal can be adjusted to compensate for the increasing height from 0 to 5%.

What types of pedestal pavers should I use for efficient drainage?

At KEKSIÄ, we offer pedestal flooring solutions for a range of applications and for good drainage properties, we recommend;

  • The Wood Deck System is an adaptive system featuring an end predisposed to accommodate any kind of joist or central block. This allows for fast and easy adjustments to be made to any type of substructure. The Wood Deck System can be used with any of our SE, NM and Star T series pedestal bases, allowing you to compensate for sloped or uneven substrate across a wide range of height variables to create a stable and perfectly level floor with excellent drainage properties.

  • The SE Series is a self-levelling adjustable pedestal ideal for sloping installation surfaces. Has a swivelling head that allows it to automatically compensate for gradients of up to 5%. It can be adjusted post-installation to ensure precise surface alignment and a perfectly level, self-draining floor.

  • The Star T Series is the world’s thinnest exterior elevated floor pedestal that’s compact in size and constantly adjustable. It can be used on any kind of floor, making it perfect for renovations and it offers precise millimetre-perfect adjustment between 10 and 30 mm for 100% level, well-drained floors.

  • The NM Series utilises a fixed bi-component head that is adjustable to the millimetre and a TW110 Twist Slope Compensator disc to allow for drainage slopes in substrate, this pedestal is popular with builders worldwide. Heavy duty and super tough, it also features an anti-noise, anti-slip head and pre-cut base for wall corner cuts.

KEKSIÄ will provide you with the pedestal flooring you need for efficient drainage

At KEKSIÄ, we service projects across NSW, Victoria, SA, Queensland and ACT. So if you’re in building or construction and want to find out more about pedestal flooring solutions, visit our Contact page or call us on 1300 633 099 to discuss your particular needs.

Article by: Nenad Pesik

Nenad Pesik is the General Manager at KEKSIÄ. He has been working in the building industry for 4 years, specialising in pedestals and raised floors. He has a Bachelor of Business Administration and on a daily basis consults with businesses to find the best solution to their construction needs.