How to make a classic timber raised garden kit. Our classic allotment style raised bed kits have three quarter inch thick timber boards and square internal corner posts. Our raised beds are available in many sizes and heights, the bed being assembled in this video is an allotment 7in high raised bed measuring 4ft x 4ft, the perfect beginners garden bed. Once assembled they are more than strong enough to contain their full weight of soil and plants. All our raised beds are treated to last longer in the elements, the treatment used is safe to use with food crops.