Described herein is a monolithic cementitious article with one or more pre-formed shaped regions. The shaped regions are generally channels that extend through a portion of the article or span the full article. The article includes one or more openings at least one of its ends. The article has a low apparent density with a high strength as well as high performance characteristics. The article when manufactured is suitable for use as a building product, such as siding, panel, trim, fascia, roofing, crown molding, decking, and fencing.