There are many by products created in industry that can be recovered or valued for the creation of new products allowing, in this way, the decrease of environmental damages caused by its disposal in landfills. This research work aims at the valuing of several industrial by-products, such as: flue gas desulfurization (FGD) gypsum from exhaust gases of thermoelectric power plants; granulate cork from insulation black cork boards; and textile fibres from the recycling of used tyres. The composite materials that come from the mixture of these products may be produced according to two different procedures, moulding or pressing, and the result will be products with different features. Through moulding one gets a lighter composite and through pressing one gets a thicker composite with higher mechanical strengths and better surface’s finishing. These composites may be used to fabricate masonry blocks for non-structural inner walls of buildings. Therefore, one has done several lab tests in order to obtain the mechanical behaviour of the referred composites so as to confirm the possibility of using it in construction.