How to design a foundation for light garden walls
To enhance the longevity of any wall, the foundation should be very strong. Therefore, foundation plays an important role for any wall.
The proper dimension of foundations should be minimum 3 times the width of a half brick wall (i.e. 34 cm/13.5 inch) or minimum twice the width of a one brick wall (i.e. 45 cm/18 inch).
In case of piers, there should be a margin minimum half a brick (i.e. 11 cm/4.5 inch) on all sides of the foundation.
Applying a sand line is treated as one of the convenient methods to label the foundations prior to excavate the trench. After selecting the location of the foundations, put a hook into the ground at each end, extend a line among the two and shake sand along the line. Eliminating the line prior to excavation, will resist the line getting in the way or to be defective. It is suggested to cut foundations horizontal all the time, on sloping ground this may imply stepping them to adapt the slope.
Begin excavating at the lowest part and go dipper unless there is firm ground. Toward a light garden wall, a trench with the depth of 30 cm (12 inch) should be appropriate if the soil is strong and well drained. But on unsettled or feeble ground, the depth should be 46 cm (18 inch).
As soon as the trench is excavated, add a peg into the bottom at one end in order that the proper level is maintained at the top of the peg with the necessary depth of concrete (minimum 15 cm (6 inch)). Then add pegs again along the trench with the application of a spirit level to maintain the top of the pegs level; reverse the spirit level among alternate pairs of pegs so as to any defect in the level can provide slight effect.
As soon as the complete length of the trench is pegged, fill the bottom of the trench with concrete (6 to 1, all-in ballest to cement) to the top of the pegs. It is recommended to place the full length of foundations in one session all the time, and ensure that the concrete is amalgamated properly.