Balcony Drainage

Our Underdeck is manufactured in Australia, and solves the age old problem for those who have wanted to utilize under the deck space and keep it dry in the wet, and also expand their outdoor living space.

Underdeck is specially designed pre-engineered ceiling system that transforms the unsightliness of the underside of the deck into a desirable and usable outdoor living area all year round.

Up to now there has not been any standard way to cover under your deck, just many individual ideas, and most are very hard to dismantle for cleaning, or retrieving something that has been dropped through from above, till now.

Underdeck panels catches the water dripping through the deck gap and channels the water away to the gutter running along one edge. Underdeck is designed to catch the water even during heavy rain storms.

It's a simple system. The water carrying panels are hung from specially designed brackets that are fixed to the bottom of the joists, with a fall towards the gutter. All the panels are interlocked to prevent leaks.




“Hi Adrian,

I am writing to let you know Greg has just completed our underdeck. We are so impressed with his professionalism, eye for detail and the workmanship.
I would highly recommend him to others, he was an absolute delight to have around, and very flexible with ideas we had along the way.

Thank you for a great product and for recommending someone who genuinely cares about what they are doing.

Many thanks.”

Kind regards, Tanya and Dave from Terrigal NSW.


“When we recently purchased our house the top balconies had open timber slats with no protection below. Underdeck was the perfect solution. Not only does it have a practical use, it looks great too. We were very happy with the service and price.”

Thanks Adrian!, Sally from Ocean Grove VIC.


“Hi Adrian just a short note to thank you and your installers for the great job you did with our underdeck at Aireys Inlet.


Your prompt, efficient service and good advice made the whole process very enjoyable.”

Thanks again, Jon and Fleur van Noorden.


“A quick note following the completion of our Underdeck this morning.
I have sent the before and after pics, because we are so pleased with the different appearance of the space underneath the deck and of course that the area is now rainproof.

We are sure that the cost for this improvement to our home and lifestyle will equate dollar for dollar directly to the value of the house.
Thank you for the advice along the way and for always being available to answer the questions.
Please repeat our thanks to the two great guys, Hamish and Greg, who represent Underdeck very well.”

Thanks again, Phil and Jen from Tura Beach.


“Just thought we would send you a note to tell you how pleased we are with the job you did for our Underdeck in Inverloch.

We are really happy with the way it now looks - so much better than the ugly underside of a treated pine deck and the fact that it has made the space useable in all weathers provides us with an asset when it comes to adding value to our house.

We were also very pleased to meet Hamish, who carried out the job, and found him to be helpful and a tidy worker.

We would be more than happy for you to use our Underdeck as an example of your work and strongly recommend you and your company.”

Kind regards, Arlene and Mark from Inverloch.


“I have just had my underdeck fitted by Greg and I am absolutely delighted with the results. I always thought it would be a practical solution but didn’t realise how amazing it would look as well. I am sure it is because your product is well thought out and designed but I also have no doubt that it looks so professional due to the enormous amount of time and effort put in to fitting it by Greg. The structure of the deck it was fitted under was originally built 20 years ago and nothing was straight or in line and it was no mean feat to fit all the blocks needed to attach the under decking system to, plus we are situated on a steep block with difficult access. Thankfully at least the weather was kind to us!

I am very seldom (if ever!) impressed by anything in this day and age and Greg has far exceeded my expectations and went above and beyond the call of duty to make sure that everything was absolutely perfect. As a bonus he was also such a pleasure to have working here, kind, considerate, clean, and tidy with impeccable manners. His attention to detail is second to none. I am very fussy but everything he did and suggested I could not fault. I have never come across a trade’s person who was such a pleasure to have in my home and I have renovated a 3 storey house so I have had my share of experience!

I wouldn’t hesitate to give your wonderful product and Greg a strong recommendation to anyone considering having this system fitted to their homes. It has made a such a huge difference in being able to use both decks in all weather and looks amazing and not like an “after thought” at all. It has added beauty, functionality and value to our home.”

Kind regards, Marie Quigg from Avalon, NSW.


“We had a significant area of balcony that needed to be protected as well as waterproofed for protection of our deck below. After lots of research we went with Underdeck. What a great decision it turned out to be. Not only was it started and finished on time but the end product was amazing. The attention to detail and the clean joins, coupled with the awesome finish has given us exactly what we wanted and more. It wasn’t expensive but you wouldn’t know by looking at it. To the boys at underdeck, thanks again and we will be recommending you to all we speak to.”

Regards, David Schwarz.


Sydney Install

“We have recently had Underdeck installed by Greg - we cannot describe how thrilled we are with the product and the job.

We have a large deck area which was half covered and half exposed - for several years we were considering how to waterproof it and researched alternative options. We had seen the Underdeck product online a year or so ago however were concerned its to how it would look. After having the opportunity to view it at a nearby home we proceeded with the job. We are amazed at how brilliant it is and how it has totally transformed the area to make it a year round useable space. We have since had several weeks of rain and it has been given a good workout - not a drop of rain made it onto the lower deck!

To top that off the installation was completed by Greg. Greg’s attention to detail is second to none. The timber deck under which the product was being installed was about 15 years old and had obviously moved over time. Greg was meticulous in the installation, no doubt struggling with varying levels and slopes, tidy, friendly and a pleasure to have around the house. On the last day he was installing the guttering and when opening the gutter supplied by the manufacturer noticed a small scratch. He immediately brought it to my attention and informed me that he had touched the scratch up but was happy to obtain another gutter from the manufacturer. To this day I still cannot find the “scratch” - which shows note only Greg's attention to detail but his honesty and integrity.

We are beyond thrilled with the Underdeck and the way it has transformed the appearance and use of our home. We highly recommend the product and in particular Greg. We would also be pleased to show the product to any prospective buyers if that will assist.”

Kind regards, Julie Somerville from Seaforth, NSW.


“My name is Ian Brown and Greg has just completed our Underdeck at Thirroul. I would like to let you know that I have never had a builder so meticulous and taken so much care and pride in his work as Greg.

The Underdeck looks contemporary, fresh and turned a very large ugly useless area into a great entertaining area. Don't ever lose Greg, he does your product proud. I will forward a couple of pics. Don't hesitate to contact us if needed.”

Regards, Ian and Rita from Thirroul, NSW.


“We have been very pleased with the UnderDeck facility that you installed at our Anglesea residence. Not only has it provided shelter to the area under our deck but it has greatly improved the appearance.

Since installation we have had several storms and the water has drained away extremely well. Also important was the fact that the installer/tradesman was good to work with and knew his job.”

Thank you, Barbara and Robert from Anglesea.


Is it just for homes?

No, Underdeck is the perfect solution for both home and commercial solutions when waterproofing under a deck or balcony is required.

It can be used as a ceiling on all types of applications inside and outside.


Which will save money when requiring waterproofing under decks and balconies, with no maintenance or painting.
It looks smart and can be used for many applications inside or outside.

It's a Green Product

Made from recycled and recyclable metal that provides strength and resistance to the harshest of elements.


The colours available are all the Colorbond colours, with the most popular being "Surfmist" an off white.
Also available - Copper, aluminium, Stainless Steel Corten and Zinc.

Underdeck is

  • Made In Australia.
  • Easy to install, DIY or have it installed.
  • Blue Scope Steel Colorbond Warranty.
  • All components are maintenance free - will not Rust, Rot or Corrode.
  • Made from recycled metal.
  • Versatile product which works with either existing or new decks.
  • Increases usable area for entertainment or storage, without weather worries.
  • Adds value, beauty and is functional.


Underdeck Brochure 1
Underdeck Brochure 2
Install Instructions

Sales Enquiries Contact

Grovetern Timberlast Pty Ltd
Adrian Hunter
0417 591 113
* Please include your postcode for all enquiries so we can estimate delivery costs.


Manufactured in Australia by Grovetern Timberlast Pty Ltd.
Suite 3C, 574 - 576 Whitehorse Rd Mitcham Vic 3132
Ph 0417 591 113.  ABN 73 104 202 057