Model # 90026431. • GoBoard™ 1/2-in is durable, lightweight, waterproof tile backer board. • GoBoard™ LT 1/2-in x 3-ft x 5-ft weighs 6-lbs, up to 80% lighter than cement boards, and is easy to handle. • Seal the board joints and fastener locations for a waterproof tile assembly per GoBoard™ installation instructions- save