🖼️
The project:
I had a concrete slab, spoon drain and grassed area that were all at different heights and created many trip hazards for young kids. I wanted a functional outdoor entertaining area that doubled as a safe place for kids to play and seamlessly connected the house with the garden.
- Materials:
Ekodeck fairhaven boards
Ekodeck fairhaven edgeboards
90x35 h3 structural pine
High strength concrete
90x90 h4 treated pine posts
Pryda M10 post anchor stirrups
10x75mm packers
75mm mixed packers
G-tape bearer protector tape
Bugles class 4 75mm/100mm/125mm
Ramplug 80mm plugs
Ekodeck concealed quick fix 3mm
Builders edge Pedestal foot XL
165mm 44T composite decking blade
165mm 40T fine finish blade
Bremick T2 SS316 65mm trim screw
Geotextile fabric
Stringline
- Tools:
AEG drill driver
AEG impact driver
AEG circular saw
2100mm straight edge
Laser
Tape measure
Rafter square
Mallet
- Step 1:
Step 1: prepare the ground
I marked out roughly where I wanted the deck to finish then hammered in some pegs and ran a string. I used this as a guide to dig out the grass and remove soil so that the deck would be about 200mm above the soil.
- Step 2:
Step 2: put in bearers
The section of the deck built over the grass was about 1.2m wide. This needed two rows of bearers spaced 600mm to support the overhanging joists. I dug the two rows of holes 1m apart, 500mm deep and concreted galvanised 90x90 200mm stirrups into the ground. The concrete slab had fall away from the house so I borrowed a laser to set the stirrups so the bearer height wound match the height needed for the joists. I left the concrete to harden for a couple of days then lay the two rows of 90x90 h4 posts to act at bearers. The posts had some twists and bowing so I clamped them to the stirrups and put bugles in each side to straighten them out as much as possible. I covered the soil under the bearers with geofabric to stop weeds while ensuring water can drain into the ground.
- Step 3:
Step 3: secure the joists
I laid out the joists to gauge spacing and avoid obstacles along the way. Each of the ecodeck edge boards and breaker boards needed two joists closer together to screw into. Once the joists were in place, spaced about 400mm apart, I propped each one up with off cuts of timber and pre drilled holes spaced 300mm apart where the timber was over the concrete slab. This is a low profile deck so I used 90x35 h3 timbers laid flat. For the portion of the joists sitting on the bearers, no predrill was needed yet. Once the predrilling was done, I put the joists back onto the concrete and used the pre drilled holes as a guide to start shallow holes with a hammer drill. I moved the joists to the side and finished drilling the holes in the concrete to ~100mm deep. I put an 80mm Ramset plug in each hole, then put the joists back in place and gently put a 125mm class 4 bugle in each hole. I used a laser to set the reference height, then put packers at each bugle until the top of the joist reached the reference height and tightened the bugles with an impact driver. The packers ended up being anywhere from 10m to 35mm high, giving sufficient space between the concrete and timber for airflow and to allow water to run off along the slope of the slab. I then predrilled and secured each joist into the bearers with two off centre bugles to reduce twists in the timber and adjusted the height slightly with packers. This process took some time and iteration to get the packer heights right, but was well worth the effort as it made installing the deck easier at the end. Each joist was slightly longer than needed so that I could trim them back at the end before laying the last edge board.
Part of the deck was also covering a concrete spoon drain and drainage pit, so the uneven ground made it quite difficult to plan out and lay the joists. I ended up using adjustable XL pedestal feet to let the spoon drain continue functioning properly. I secured the pedestal feet with plugs and bugles then attached the joist with some smaller galvanised screws.
Once all the joists were in, I covered them all with 100mm joist tape to protect the timber from moisture.
- Step 4:
Step 4: lay the boards
Now the satisfying part - laying the boards! I started with the edge board closest to the house and the perpendicular frame board along one side. I don’t have a drop saw so I did a mitre cut with a circular saw and rafter square which worked just as well. I then started laying the rest of the boards against the frame board, getting a 3mm gap on the edge using packers before securing the length of the board with 3mm concealed quick fix clips on each joist. I used a mallet to gently hit the boards snug against the concealed clips to ensure a consistent 3mm gap along the length of the boards. The other end of these boards needed a breaker board as my deck is wider than 5.4m, so I didn’t need to cut these boards until they were all laid. When the boards were all down, I cut the breaker board to length and placed it on top to mark out where it would go with a pencil. Using a straight edge an a guide, I cut along the line with a circular saw set to a depth of 23mm to avoid cutting the joists and removed the excess material. I then secured the breaker board and continued to lay the rest of the boards on the other side, repeating the process to install the other edge board.
Once all the boards were laid apart from the final edge board at the end parallel to the house, I marked where the final board would sit and cut each joist 23mm shorter as this is the width of the decking and would let the face boards sit flush with the edge of the deck. I then secured the edge board, pre drilling and top fixing with stainless steel trim head screws as recommended by ekodeck. As a side note, the ekodeck deck planner and installation guide were both extremely useful through the project.
The finishing touch was putting the face boards on the exposed edges. I clamped these onto the deck in position and secured with screws in the same way as the edge boards.
