Local clayey raw materials and feldspathic rocks of Eskisehir sources were characterized, and its influence in facade cladding tile compositions was evaluated. Dilatometric studies for disclosing peak firing temperatures and regimes showed significant and substantial linear shrinkages as densification proceeded. The results also indicated that the standard composition did not resist over 920 degrees C. Body compositions containing feldspathic rocks yielded the lowest water absorption and highest strength values at 1160 degrees C due to improved densification. SEM of a selected sample at 1160 degrees C showed the presence of uniformly distributed, spherical and isolated pores in the matrix. In addition, water absorption values were advanced in group AII(a) European standards (EN 14411), breaking strength increased and acceptable colours were obtained.