Timber Deck Building: 10 Tips to Do It Right the First Time
February 2023
Author: Thor Diesendorf
There’s no better way to enjoy your outdoor space than on a recycled timber deck. Not only will it make your outdoor space more liveable, it will also raise the value of your house significantly. But a timber deck can be a big investment, so it’s worth getting it right the first time. If it’s worth doing, it’s worth doing right!
Thor’s Hammer has been supplying timber decking for over 20 years, and over that time I’ve seen a lot of common mistakes made. So to make sure you don’t make the same ones, read on for some of our top tips to installing a deck that will last for many years.
1. Find an experienced decking installer for the job.
It’s important to find someone who has reasonable deck installation experience. Even better; someone who has extensively worked with hardwood timber.
If someone has a proven track record and a reputation to uphold, they will be more likely to put in the extra effort to do a great job. Unfortunately there are some dodgy deck builders out there, so it’s important to be wary of this.
Here are some tips for finding an experienced deck installer:
Ask for referrals from your friends, family and any trusted community of Facebook groups you’re a part of.
Search online (far and wide). Online directories can be good, but make sure to cross reference any listing with the person/business website and social media. Read reviews and take note of ratings, and call for a quote if you still need more certainty.
Check their qualifications. Deck installers should have an Australian Builders Licence, and some will have further training specific to deck construction.
Ask us! We have a few providers we can recommend in Canberra. Call us on 6282 9900 or email hammer@thors.com.au. If you’re outside of Canberra, try calling your local lumber business.
2. If you’re going down the DIY route, research extensively and don’t be shy about calling in favours.
Depending on your starting point, DIYing your own timber deck can be a huge task. It requires a skillset that for people who don’t work in construction, is rare.
It’s worth doing a pre-project calculation to decide whether DIYing is really the right pathway for you. Calculate the cost of materials, new equipment or machinery that you’ll need to purchase, and your own hours spent researching, sourcing, building and maintaining. Then compare that against a few quotes from local (highly recommended—see above) decking installers. It may be that outsourcing this job will save you a lot of heartache, result in a better end product and potentially not cost you a huge amount of extra money.
But if you do want to DIY, there are two key things to do; research extensively and call in favours from your friends and family. If you’re missing essential skills required to build a timber deck, perhaps there’s someone in your network who has done it before who can show you the ropes? Or if you’re getting on in years, perhaps a younger relative can help with some of the laying? When it comes to equipment, rather than going out and purchasing new everything, reach out to your network to see if they have things you could borrow. Or, you could contact your local Tool Library to borrow some of the things you need and return when your decking is complete.
Initial research should involve a Google session, getting a feel for the project. YouTube is chock-a-block with useful videos on the macro and micro aspects of timber decking projects.
You’ll need to research and consider things like:
Council regulations and approvals
Your local climate conditions (i.e. Are you in a bushfire-prone/ flood-prone area?)
Building requirements for damaging / deteriorating weather conditions (e.g. Underdeck waterproofing, drainage and run-off for heavy rain, shades or covered pergolas for direct sunlight/ UV and wind)
Aesthetics and style
Deck use (i.e. How will the deck be used? By whom/ how many people? What furniture will need to be accommodated?)
Privacy (if you have nearby neighbours)
Access (e.g. Will it need to be easily accessible and visible from the house?)
There’s a range of equipment you’ll need—here’s a basic list to start you off:
Tape measure
String line
Spirit level
Hammer
Led pencil
Electric saw
Nails/ screws
PPE (googles, mask, gloves, ear plugs, thick boots)
Hand drill
Sander
Concrete
Next, check the forums online to get an idea of other people’s experiences building decks. If you can sift through the BS, there is good info on forums like whirlpool, homeone or Renovate Forum.
The Wood Solutions site also has good info on decking, with a Domestic Timber Deck Design guide. It’s a bit dry and technical, but the information is all there.
3. Use well-seasoned (instead of ‘unseasoned’) timber for decking.
Finding the right timber at the outset will save you years of hassle. Timber that’s the wrong species, moisture content, age, or type can warp and decay long before it should, making it unstable and potentially dangerous.
As such, it’s important to use well-seasoned timber that has a low moisture content. ‘Seasoned’ timber is timber that’s been dried to particular moisture levels, either manually or naturally. Seasoned timber is more stable, meaning it doesn’t fluctuate in size as much as unseasoned timber, with changing humidity and weather conditions. All timber will expand and shrink to a certain extent, but seasoned timber less so.
Our recycled timber decking is well-seasoned, sourced from the roofs of old buildings. To make the decking, we saw our 100 x 50 mm stock (also known as 4x2 inches) in half—these were once the rafters, joists and bearers of the roof structure, and as such having been sitting in this super dry and warm environment for 50 to 100 years. The roof cavity essentially acts as a kiln, and so the end product of our recycled timber is a really good quality seasoned hardwood.
4. Choose your decking timber species carefully.
Decking that is going to be outside in the weather (most decking) needs to be built from the most dense and durable timber species available.
For this, I recommend the toughest recycled Australian hardwood species that we have in stock - Class 1 Durability species like Ironbark, Turpentine, Tallowwood and Blackbutt.
These species are not only durable, but are also nice to look at. When left uncoated, the timber will grey over time giving it a rustic, lived-in look, which some people love. If you prefer to avoid this happening, and to instead keep the original colour and appearance of the timber, then you can coat with an oil-based finish (more on that later on).
Dressed and rounded - Ironbark / Dense Reds hardwood decking (mainly Ironbark, Forest Red Gum, Turpentine and Red Mahogany).
Dressed and rounded - Blackbutt / Dense Browns decking (mainly Blackbutt, with small amounts of Stringybark, Silvertop Ash and Tallowwood).
5. Only use ethically sourced or recycled timber.
This point is more about ‘doing the right thing’ rather than the quality or structure of your decking. And perhaps I’m a little biased when it comes to advocating for the use of ethically-sourced or recycled timber. But it’s important to remember that there are a number of environmental reasons why it’s better to choose recycled timber over new timber.
Using recycled timber allows the carbon already stored to remain 'locked up', and there are less ‘carbon miles’ in using recycled timber as well. You also need to be wary of illegal logging. It’s occurring less often these days due to better regulation, but it still exists.
Watch out for rainforest timbers like Merbau and Kwila because a lot of that timber has been illegally logged out of a rainforest somewhere in Java. Rainforest logging in South-East Asia is a massive environmental issue both for deforestation and for habitat destruction of rainforest animals.
At Thor’s Hammer, we’re passionate about creating demand for recycled timbers because we believe that if the demand for these illegally logged rainforest timbers diminishes, the harmful practice will hopefully cease.
6. Lay the boards according to your timber choice, with a larger gap for well-seasoned timber.
When laying the boards, you or your builder will need to make sure you’re leaving the correctly sized gap. If your builder is used to working with unseasoned timber, they might leave a smaller gap than is necessary, expecting the timber to shrink in time.
This can be an issue because with the boards too close together, any water that falls on the deck can’t drain away, which can potentially cause pooling, mould, rot and decay.
If you or your builder doesn’t leave the right sized gap between the decking boards, your deck will look fantastic when it is installed but within a few years will be warped, cracked and a real liability (see the photo below).
Too large a gap isn’t great either as cutlery and other items may fall through the cracks. It’s one of those things you just need to get right!
This shows the results of laying boards too close together without enough gap. Rain has not been able to drain off and the moisture has caused the boards to expand and close up even more, only increasing the problem. Because the boards are staying damp this has caused the timber to deteriorate. Expansion of the boards can also be caused if the deck is built too close to the ground or the drainage is bad under the deck.
The cladding of the front of the deck is in contact with the ground. This is causing the boards to absorb a lot of moisture from the ground and expand. They have expanded and popped right off.
8. Think about building a covered timber deck to protect it from the elements.
Much of Australia has very high UV, hot and dry summers and wet and cold winters, and these conditions can have a significant impact on outdoor structures with exposed timbers, such as decks.
Temperature, humidity, direct sunlight and wind levels can also have an impact on the longevity of your timber decking. By building your deck under a closed or semi-closed pergola-type structure, you can protect the timber—to a certain extent—from those conditions, saving time and money on regular maintenance as well. A covered deck will also open up more options on timber species, which could save on costs.
Plus, covering your deck creates an outdoor area that is usable for more months of the year, especially when it's super hot or very wet (read: ‘Triple El Niño followed by triple La Niña!’— terms we’re unfortunately now all too well acquainted with).
9. Stay away from water based finishes to avoid decay.
Water-based finishes used on your timber decking can trap moisture in the decking boards and cause accelerated decay, so it’s best to avoid them. If left too long, this can lead to a loss of structural strength in the timber. At best this is ugly. At worst, a hazard.
Instead, I recommend an oil-based finish, which will help the timber repel moisture but still allow the timber to breathe. I recommend (and supply) Osmo finishes from Germany for pretty much all of our products. For decking, you can use Osmo Decking Oil, which will last around 12 months in full sun.
Maintenance on your pergola and decking is an ongoing process—it’s not something you can do once and leave it there. But applying Osmo’s Decking Oil correctly once a year will dramatically prolong the life of your recycled timber deck, so it’s definitely worth it.
10. Enjoy the process!
Whether you decide to work with a deck installer or DIY your timber deck, I hope you enjoy the process and come out the other end with a stunning, practical and long-lasting recycled timber deck where you and perhaps your family can make some memories for years to come. We’re extremely passionate about making products that are high quality. The longer these timber products last—whether it’s decking or cladding, furniture or joinery—the better it’ll be for both the environment, and your bank balance!
TIMBER DECKING FROM THOR’S HAMMER
Recycled timbers make a great decking board. They are well seasoned and will not shrink, and our Australian hardwoods are dense and durable.
Thor’s Hammer makes two main kinds of timber decking boards from salvaged hardwood roof timbers. One of the most common stock sizes we receive from demolitions is our 100 x 50 mm stock (also known as 4 x 2 inches). We then saw these in half to make our 100 x 22mm timber decking boards.
Our customers then have two options; we can either wire brush the rough sawn face for a rustic decking board, or we can dress the timber and pencil round the edges to make a clean dressed 83 x 18mm decking board, for a smoother, cleaner appearance. Learn more about our timber decking.
If you’re interested in building a deck for your home and you’re after some high quality, sustainable, salvaged and recycled Australian hardwood timber, fill out an enquiry form via the button below. We’ll contact you to offer a quote and to answer any questions you have. Good luck!