Marking out the Deck Site
The wife and I went outside for a a couple of hours tonight and build up the deck/garden bed/playhouse/sandpit site with stakes and string lines. A couple of things were apparent immediately. Firstly, the combined sandpit/playhouse was clearly too small, and was changed to 2.3 meters long from the original 1.8. Also, the lines of the garden bed between the deck and the existing lawn looked ugly. We used the garden hose to come up with a pleasing wavy edge for the garden bed that we were both quite happy with.
Getting a 90° Angle
Critical to the entire layout of the deck was getting an edge that was at 90 ° from the existing paving along the back of the house. To achieve this with the string line I used the 3/4/5 triangulation method. Put simply this was done by measuring 3 meters along the paving from where the deck would come out. I placed a peg at this location and attached 5 meters of brick laying string to the peg. Using a can of marking spray paing I marked an arc by stretching out the 5 meters of string and holding the can of paint at the same distance and then rotating the string on the peg. I attached another peg at the paving where the deck would come out and to this peg I attached 4 meters of string. I marked out an arc in the same way until the two arcs intersected at one point. The line between the second peg and the intersection point gives you a line that is exactly 90 ° from the line of the pavers.
The idea of building a deck was exciting to me, and would be far and away the most ambitious external construction project I had attempted. Deck building is several steps beyond constructing timber fences and privacy screens that I had done before. I decided that to help track my ideas and efforts that went into the deck building that I would keep a small diary of the whole project. And this is it.
Preparing for Excavation
The excavator cannot excavate right up to the edge of the pavers, garden shed, or the fence. I spent an hour using the pick and shovel on our hard clay soil along these edges and removed about 30 cm of material to a depth of 20cm. Thankfully the weather was quite cool so I managed this pretty quickly.