Specification for Face Brick

- ASTM C216 Facing Brick

- ASTM C652 Hollow Brick

- CSA A82 Fired Masonry Brick made from Clay or Shale

Note: The Canadian (CSA) equivalent references are included in brackets behind the US (ASTM) references.

This specification covers brick intended for use in masonry, either as face brick or in structural applications. According to ASTM C216 (CSA A82), a solid brick can have core holes whose area is no more than 25% of the total bed surface of the brick. While 100% solid brick are normally available, most brick are manufactured with 25% core holes. ASTM C652 covers hollow brick which have core holes whose area is more than 25% of the total bed surface of the brick.

This profile covers many of the most important aspects of this specification. When a brick is specified by an architect, the specification identifies the brick's manufactured name, ASTM (CSA) specification number, the grade, the type and the brick's manufactured size. For example, a typical brick specification could be Hanson Brick #630 which meets ASTM C216 (CSA A82), grade SW, type FBS whose size is 2 1/4" by 3 1/2" by 7 5/8" (57mm x 90 mm x 190 mm) (modular size.)

The "grade" classifies the brick's ability to resist damage by freezing when wet. If the moisture inside a brick freezes, the water expands. If there are many cycles of freeze/thaw, the face of the brick may crack and fall off. There are two grades, SW severe weathering and MW moderate weathering. Grade SW is the most stringent and is normally required in most parts of the United States and Canada.

There are two physical properties of brick that are good predictors of the brick's ability to resist spalling or cracking of the face. These are the 24-hour cold water absorption of the brick and the saturation coefficient which is the ratio of the amount of cold water a submerged brick will absorb in 24 hours to the amount of boiling water a sub- merged brick will absorb in 5 hours.

The theory of the saturation coefficient is that if only part of the total pore space is occupied by water, there is room for expansion on freezing into the remaining pore space without disruption of the material. The smaller the saturation coefficient, normally the more durable the brick.

Compressive strength is the maximum weight the brick can support without breaking. For grade SW brick, the average compressive strength of 5 brick must exceed 3000 PSI (20.7 MPa) and the saturation coefficient cannot exceed .78.

There are two alternates if the average saturation coefficient exceeds .78. First, the cold water absorption of 5 brick cannot exceed 8.0%. Second, the brick must withstand 50 cycles of freeze/thaw testing.