Many materials may be used. The sides should be loose enough to provide some air movement through them. One side should open for easy turning and removing of the compost. The pile may be round, square, or other convenient shapes. Special composting bins are commercially available.
Many people construct their own.
See your county agent if you need blueprints for compost bins. Fencing materials need corner supports, although a small round pile made of slatted fencing needs little or no support. Bricks, or concrete blocks, may be stacked without mortar. Space should be left between blocks to allow adequate air movement through the sides. Scrap boards are suitable for sides if there is enough space left between them for air movement.