It should be noted that, both strength and lengthening of the material when it rupture is not at all the main indicators in the design of any kind of structures. Regarding the accounting of the reinforcing strata, in order to determine stability, consists precisely in checking not exceeding prolonged stability when performing certain calculations. Based on this, in order to correctly compare the materials should be arranged by the available calculation values on the basis of which the corresponding calculations can be carried out.