Mortar Testing

The project specifications for mortar provide that mortar must comply with either an ASTM C270 or ASTM C780 standard.

ASTM C270 states the required proportions of mortar ingredi­ents (1 part Type S masonry cement to 3 parts masonry sand), while ASTM C780 states the method of obtaining samples for compres­sive testing and the strength required for the mortar. Copies of these ASTM standards must be obtained to ensure full compliance with both the project specifications and industry standards.

8.4.3.5.1 Heating, Ventilation, and Air-Conditioning Testing Although HVAC testing is performed by a professional testing agency, quality control personnel need to understand how and why these tests are performed so they can be performed at the appropriate times. The ductwork joint leakage test is performed after the ductwork is completed, prior to the insulation being installed on the outside of the ductwork. Performing the leakage test requires that all openings in the ductwork are sealed up. A high-powered fan is then used to "pressurize" the ductwork to a specified level. The project specifications will either state this pressure level or will refer to the SMACNA (Sheet Metal and Air­conditioning Contractors National Association) HVAC Air Duct Leakage Test Manual. Once the proper test pressure is reached, it will be watched for a drop in pressure. Any drop in pressure indi­cates the existence of a leaky joint in the ductwork. If this occurs, each joint must be corrected and retested until the proper pressure is maintained. HVAC system balancing adjusts the system to work properly. This ensures that the measurement of actual air volume meets the designed air volume.