Building a terrace in the back

When building our garden, the most anticipated project was to build a sizeable terrace in the back, effectively extending our living room into the garden.

I modelled the terrace using Google SketchUp which allowed me to visualise the result and to plan and buy the needed of material. It also served me as a blueprint during the work.

Model of the terrace

I also modelled a view of the entire terrace area, using Google SketchUp, which later served me to decide the size and position of the sun-sail shade. For the terrace, this mainly aided me in visualising the final result.

Model of the terrace area

I dug up all the earth and moved it aside to use later for levelling the new lawn and landscaping the area of the path. There was a lot of earth, 20-50 cm deep over an area of about 25 sqm, which I happily moved with shovel and wheelbarrow. I also removed a number of square concrete slabs of the original paved “terrace”. Under the layer of earth I found gravel that I dug up to the depth of the foundation for the framework on which the decking would rest. As in the fence-post holes, I found plenty of lovely granite rocks of various size that I put aside for later use in the garden. Once deep enough, I placed for each of the supporting lower layer framework beams a foundation of four concrete slabs, each on a sand bedding (recaptured from the originally paved area). Those slabs I carefully levelled out so that the framework would be exactly even. Then I screwed the supporting beams onto the slabs. Once the bottom layer of the framework was in place I covered the slabs and the bottom half of the beams with gravel ensuring a sound foundation. Reusing the concrete slabs this way saved me the trouble of messing around with concrete for the foundation. The beams are of best quality impregnated timber that will last for decades even when touching moisture-transporting earth and gravel. Then I moved and levelled the gravel in the area of the decking such that it was sloping 10% away from the house, ensuring that water would drain away from the house and would not damage the foundations in the long run. Then I added the top layer of the framework, which were beams with 30 cm gaps, as I did not want the rather thin decking boards (19 mm) to swing. This was also the time when I dug out the hole were I would plant the tree on the terrace, digging 80 cm deep from the level to which I would fill up with earth and 70 cm diameter. This hole I filled with earth. I added additional cross-beams to the top-layer of the framework around the hole, creating a hexagonal frame to support the decking edges around. I also added a cross-beam along the house wall and cross-beams along the rock wall towards the forest, as close to the rock as I could manage. I added water-permeable covering sheet over the gravel to prevent weeds to grow out of the gravel through the gaps of the terrace and stapled them to the framework. Then I started to measure, cut and screw tight the decking, starting from the side of the house. To create the hole for the tree I selected suitable bits of board to fit the area around the whole and placed them on an even plane (previously completed decking), laying them relative to each other just as they would be fitted. I took an excess piece of wood, fixed a screw and placed this with the screw exactly in the middle of the to-be hole. then I took a string, made a hoop at one end and slung it over the screw. I knotted a pencil to the string at exactly 30 cm from the screw and keeping the string tight drew an exact circle with 60 cm diameter on the decking boards. With my electric jigsaw it was easy to get the exact round cuts and I could fix the tailor-made pieced leaving a perfect hole. As my gap between framework beams was 30 cm and the beams themselves 45 mm thick, the decking was standing out about 2 cm from the supporting framework, being well supported but covering it from sight. The decking along the rock I measured and cut with the jigsaw leaving just a 1 cm gap between rock and decking. Around the post supporting the balcony and the rainwater drainage sewer and pipe I build neat square housing hiding a concrete foundation in case of the post and creating a cover that can be removed to clean the sewer from leaves in autumn hiding all but the pipe. I treated the decking with uncoloured linseed oil (this is actually yellow and has a darkening, browning effect on wood, but there are also linseed oils on offer that have extra added colour). The so-treated thermo-ash decking turned into lovely chocolate-coloured darkish brown with a tiger-like pattern of the wood.

Chocolate-coloured thermo-ash decking