The SCBA waste used in this study is a low-cost material, rich in silica (SiO2), which behaves as a filler material and reduces the clayey formulations plasticity. FTIR and XRD techniques enabled a detailed characterization of mineralogical and structural deformation. The trend observed in the crystalline nature of the main mineral quartz through XRD very well matches with the results of FTIR. The study indicated that the changes in the brick production process were not needed. The LDN193189 coefficient (k) values for the different wt.% addition (SCBA) into clay brick samples were studied. From the analysis, the following conclusions were drawn.(i)The unfired brick samples (S1) has contained kaolinite (47%), quartz (44%) as major minerals and hematite (9%) at minor level.(ii)The unfired samples (S2–S5) have shown the presence of lignin (32%), quartz (20%), kaolinite (16%) and calcite (16%) as major constituents and others were at moderate level.(iii)The fired clay brick samples (S2–S5) have revealed the presence of lignin (28–39%), quartz (17–20%) and hemicelluloses (12–18%) in major proportions. The other minerals like hematite and magnetite were found at minor level.