We carried out a range of works for our client, including constructing retaining walls using different methods. For the foundation, we used either cemented-in ground wooden 4x4 posts or concrete. Sleepers were securely attached to the posts, with the inside lined with waterproof polythene to aid future timber rooting. We filled the space with soil improver, and in both methods, back fills behind the retaining walls were done with gravel. In the case of an upright sleeper wall, we dug a trench, cemented the sleepers vertically, and screwed them together. For a brick retaining wall, we created a concrete footing, built a 9-inch solid concrete wall, and finished it with a brick face.