Like other architectural concrete masonry, glazed block provides an attractive finish without the need for further surface treatment. Glazed units impart a smooth, even reflective surface, in colors ranging from subtle earth tones to pastels to vibrant primaries. HOW THEY'RE MADE Glazed block are regular concrete block with a tile-like surface permanently fixed onto one or more faces. A composite of glass, pigments, and binder is injected or molded onto the surface of a cured concrete block. The units then pass through a kiln to fuse and permanently bond the glaze to the unit. PROPERTIES Glazed block are covered under ASTM C 744, which provides standards and testing requirements for dimensional tolerances, crack resistance, chemical resistance, adhesion, abrasion resistance, surface burning characteristics, colorfastness, soiling, and cleansability of the facing. CUSTOM PRODUCT Glazed block must be ordered and custom-made for each job, because the variety of available colors and shapes make it impractical to maintain a standard inventory. EXTERIOR USE Manufacturers say glazed block can perform well as an exterior material in virtually any climate, as long as walls are designed and constructed properly. Controlling moisture penetration is the key to successful exterior performance. Proper copings, flashing, and weep vents must be provided.