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Prefabricated pergola erected on a new low-level composite deck installed over a treated Pine frame.
The project
The homeowner had a large raised area in her backyard that was sloped but only accessible by steep stairs made of retaining-wall blocks. She wanted a small viewing deck up there, with a gazebo, that would be easy to access and be low maintenance. So we decided to make a deck using Ekodeck Designer Series boards. These cost about $18 a metre, but are maintenance-free and faster to install than traditional decking.
This deck was built on sloped ground with low gradual steps to provide easy access for the elderly homeowner. I originally posted with some questions about a frame for a low-level deck. The job is now finished, so I thought you might like to see the results. Both the homeowner and I are very happy with it. All the materials used (with the exception of the Tasmanian Oak for the handrails) were purchased from Bunnings.
Tools and materials
Tools and materials used for the project:
- Saxony BBQ gazebo
- Ekodeck Alpine Ash/Ironwood designer series decking
- H3 Treated Pine 140 x 45mm
- 150 and 175mm batten screws
- 100mm batten screws
- Mitre saw
- Pryda timber connector screws
- Galvanised brackets
- Ekodeck Quickfix timber joists
- Ekodeck Quickfix C clips
- Balustrading kits
- Marine timber varnish
- M12 bolts
- Bitumen
- Weed mat
- Galvanised strapping.
Steps
Step 1
I wanted to make the steps as low as possible, so I used a single layer of 140 x 45mm H3 for the structure, with posts set back from the edge to give it a floating appearance. There was a rise of about 850mm from the retaining wall stairs to the deck, which allowed for four steps rising 170mm each time.
The homeowner wanted the structure to be about 3 x 3m. Since I wanted to minimise wastage of the expensive Ekodeck, I came up with this framing design (below). The double blocked out edges allowed me to picture frame all around the deck. The double and centre beams had the posts under them as the supporting beams.
For this job I also had to remember that I was adding a gazebo, so additional noggins were required to make sure I could attach the gazebo through the deck to the framing for sufficient strength.
Also remember you'll need to have the decking overhang the frame by 25mm all around if you intend to add fascia boards to hide the frame.
Step 2
For single-layer framing, I find it easier to build the frame first, prop it up to get it perfectly level, then hang the posts in the holes and concrete it in. Here I've built the frame using nails as well as 150 and 175mm batten screws (hangers and angles will be used later to reinforce all joints).
Note the weed mat and the posts hanging in holes. I painted the posts with bitumen to give them additional protection. The ratchet strap is to hold it perfectly square while concreting. Galvanised strapping was later added during the reinforcing stage.
Step 3
Once the concrete was poured, I added galvanised brackets to reinforce the frame, diagonal strapping to keep it all square, and joist hangers where appropriate. I also painted the rest of the frame black, as it looks much better with the Ekodeck than naked timber underneath.
The orange screws are Pryda joist hanger screws which are much faster and easier than nailing in the hangers.
Step 4
I then built the rising stairs. Really, these are like four mini-decks and constructed with the same principles as the main deck. Since I had a rise of 170mm each step, the 140mm framing needed 30mm spaces in between each step.
The steps had to change direction 45 degrees to meet with the pre-existing retaining wall steps. Thankfully, my mitre saw made the fiddly angle cuts a breeze.
As you can see, each step is supported at the front with a concreted in 90 x 90mm post. I usually put posts under the framing for better support, but it wasn't practical for these stairs. So, I later reinforced with plenty of M12 bolts.
Before adding decking, I covered the weed mat with gravel to prevent it flapping in the wind, as well as reducing splashes when it's raining.
Step 5
Then it was time to lay down the decking. Since Ekodeck expands with heat laterally, you need to have 6mm expansion gaps at all ends, which can get a bit fiddly with the mitres on the dark picture framing.
One thing to note if you want to do this - the Ekodeck Edge Boards are held down with hidden C Clips (you'll know what I mean if you use them). The Quickfix Kits that Bunning sell contain nowhere near enough C Clips - 14 are provided, but I needed something like 70 for the picture framing. Thankfully, you can buy them separately.
Step 6
The Saxony Gazebo was easy to build, taking me a day solo, including giving it a coat of Marine timber varnish. It includes 50mm concrete screws if you are fixing it to a slab, but I used 100mm batten screws to fix the steel feet through the deck into the framing, making sure it won't be going anywhere.
Step 7
Then it was time for the last step, adding in the handrails. These are not required by code as the deck is less than 1m high, however the elderly homeowner requested them for ease of access.
Because the stonework had been done earlier, I had to use post brackets on the first rail to support them. The brackets have a little flex in them when not supported otherwise, so I connected them directly to framing where possible. Note the lateral bolt going into the wall halfway up the first post for extra strength. The stainless-steel balustrading wire was not required by code but is a nice addition.
The last handrail was connected directly to the deck frame with M12 bolts.
Step 8
And she's done, ready for the landscapers to come in and plant around it. Thanks for the guidance and help I've received from these forums in the past and I hope this post helps someone else down the way.
How to build a low-level deck
Experienced Community member Adam has provided the helpful guide How to build a low-level deck, which includes all the issues you should consider for a successful project.
More inspiration for your decking project
Workshop member Aliti1 revamped his backyard area by building a low-level Merbau deck over concrete and gravel.
This backyard makeover with multi-level decking by community member Rufaro turned a neglected area into a functional outdoor living space.
Check out our Top 10 most popular outdoor projects, Top 10 most popular deck projects and Inspiring low-level deck builds for many more creative ideas.
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