The trade name "Five X", (5X and XXXXX) refers to all red cedar shingles that are 16" (406mm) in length, including all grades. Five X shingles are 0.40" (10mm) thick (nominal - all grades). The recommended exposure for a 16" shingle roof is 5" (125mm) for a 3-ply, water tight construction. 

In the USA, Five X shingles are traditionally used in California, the southwest and western states, in all grades, for roofs and walls. In England and South Africa, almost 100% of the cedar shingles imported are #1 16" 5X. Approximately 90% of the shingles used in England are CCA preservative treated, and in South Africa many of the roofs receive a heavy coat of linseed oil to help them withstand the hot dry climate. These versatile wood tiles are also commonly used in pockets of Europe where they are similar in size to the domestic production of 40cm shingles or shakes.