Twinson decking is virtually maintenance free and is manufactured from a combination of wood and upvc. Twinson® Terrace boards have a wood brushed finish on both visible faces, with anti-slip grooves for safety and comfort. The boards are double-walled, with a thickness of 28 mm and a useful width of 140 mm. They are joined invisibly with system-specific assembly clips. The clips produce a fixed gap of approx 4 mm between the boards. Edging trims are available for finishing off the deck perimeters.