We use the gorgeous, solid Cypress Pine - Super strong! Single: 1.8m w x 2.8m h and Double: 2.7m w x 2.8m h. NOTE: Swing Frames must be installed on a solid, flat and level surface.
You must allow at least 2m space from any solid structures surrounding the swing frame including 3.5m in front and 3.5m behind the unit to allow adequate swinging space and ensure safe use.