This specification covers two types of finishing hydrated lime that are suitable for use in the scratch, brown, and finish coats of plaster, for stucco, for mortar, and as an addition to Portland-cement concrete. The two types of lime are Type N and Type S. Finishing hydrated lime shall show no pops or pits. Chemical composition shall conform to the required contents of calcium and magnesium oxides, carbon dioxide, and unhydrated oxides. The plasticity figure for the lime is specified. The following test methods shall be performed: chemical analysis and physical tests.

1.1 This specification covers two types of finishing hydrated lime that are suitable for use in the scratch, brown, and finish coats of plaster, for stucco, for mortar, and as an addition to portland-cement concrete. The two types of lime sold under this specification shall be designated as follows:

1.1.1 Type N—Normal hydrated lime for finishing purposes, and

1.1.2 Type S—Special hydrated lime for finishing purposes.

Note 1: Type N, normal finishing hydrated lime, is differentiated from Type S, special finishing hydrated lime, in that no limitation on the amount of unhydrated oxides is specified for Type N hydrate, and the plasticity requirement for Type N hydrate shall be determined after soaking for 16 to 24 h.

Note 2: For lime putty, refer to Specification C1489.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.