Incineration is widely used in France and through the world as a technique for eliminating waste using waste incinerators or biomass boilers. Products resulting from incineration are fly ash and bottom ash. Types of ash are depending on incinerated waste or raw materials i.e. coal, wastepaper, wooden waste, dewatered sludge … They can contain more or less pollutants depending on materials incinerated. This paper focuses on the reusing of a specific ash from incineration of de-inked wastepaper sludge added with wood waste in a biomass boiler. Based on wastepaper sludge ash—WSA-physical and chemical characterization, different compositions have been investigated to recycle WSA as materials. WSA can be used as binder or additive in different mixtures tested. A complete program was achieved to define procedures and methods, to carry out mechanical tests and to analyze WSA-based mixtures. The objectives are (i) to devise the most efficient methods to reduce WSA and to recycle the maximum of WSA ash in manufactured materials used in the field of building and (ii) to use the least possible amount of cement replacing it with waste paper sludge ash so as to obtain alternative materials limiting print carbon.