Abstract: A building material includes a layer of a first cured material and a layer of a second cured material interlocked with the first material. Each cured material includes a mixture of (a) fibers made from a light-weight material (e.g. cellulose), (b) a material (e.g. cement) curable to produce interlinked molecules bound to the fibers and (c) particles of a material (e.g. sand) for tempering the cured material. The weight per unit volume of cellulose in the first material is greater, and the weight per unit volume of cement (or sand) is less, than the respective weights per unit volume of cellulose and cement (or sand) in the first material. The second material may constitute a compressive member when cured. A porous (non-woven) tensile member is adhered to the first layer at the face opposite the second layer to maintain the layers under tension in a particular configuration. A thin layer of a material (e.g.