This paper presents an experimental research on the durability performance of compression molded sisal fiber–cement mortar laminates (SFRML). To obtain a material with enhanced performance, the used methodology was to replace the Portland cement (PC) by calcined clay (metakaolin and calcined waste crushed clay brick) in order to produce a matrix totally free of calcium hydroxide (CH). The content of calcium hydroxide in the matrix was determined by thermal analysis. SFRML were then produced using both a PC and a CH-free PC-calcined clay matrix and the composites were submitted to accelerated aging through cycles of wetting and drying. The durability of the SFRML was investigated by determining the effects of accelerated aging on the microstructures and flexural behavior of the composites. The results indicate that the newly developed CH-free matrix avoided the fiber embrittlement process keeping the toughness in time even after 100 cycles of wetting and drying.