Gunnable sealant codes speaks to what are gunnable sealant codes and why use gunnable sealant codes.
These are specifications for gunnable joint sealants according to ASTM Standard C920, which defines designations for sealant Type, Grade, Class and Use. These codes which provide specifications detail how the various types of sealants must be applied and when the various sealants are required.
Type S sealants are single component and require no jobsite mixing.
Type M sealants are multi component and must be mixed on the jobsite before installation. Multi component sealants generally cure faster than single component sealants. They also allow a greater variety in colour choice, as dye packs can be added during mixing.
Grade P sealants are also called self levelling and are pourable. They are easily installed in horizontal paving joints Except for vertical wall joints, Type NS nonsag sealants must be used.
Class defines the elongation capability capability of a sealant.
A class 25 sealant can tolerate 25 percent expansion and contraction under normal usage.
A class 100/50 sealant which is the highest Class designation in the current standard, can tolerate 100 percent expansion and 50 percent contraction.
A Use T, traffic sealant can tolerate wear and physical abuse of pedestrian or vehicle traffic as most pourable sealants also are Use T configuration.
A Use T, nontraffic sealant is not suitable for traffic exposure and is normally intended for use in vertical wall joints.
A Use I, immersible sealant is suitable for sealing applications that will be submerged once the sealant has cured.
Sealants may also be classified as Use M, G, A or O, meaning that they have passed a series of tests demonstrating satisfactory adherance to mortar, glass, aluminum or other materials respectively.
As an example, a multi component sealant intended for expansion joints between sections of aluminum curtain wall, which must be capable of 50 percent elongation, can be specified as Type M, Grade NS, Class 50, Uses NT and A.