Masonry Special Inspections - COVER THE MASONRY SAND

Should the masonry contractor cover the masonry sand stockpile at the job site when not making mortar during construction? Yes! Does the masonry code require that the masonry sand be covered at night and other times? Yes – but the language is a little nebulous.

Article 1.7B of the masonry code (TMS 402/602) states, “protect cementitious materials for mortar and grout from precipitation and groundwater,” and goes on to say that “the performance of masonry materials can be reduced by contamination by dirt, water, and other materials during delivery or at the project site.” (COVER THE SAND.)

The materials in a mortar mix are proportioned by volume, and when masonry sand takes on more moisture from rain, it bulks. When wet sand bulks, the field employee making the mortar gets less sand in the volumetric measure used to produce it. Statistics show that a 5% increase in sand moisture can increase the volume by 20% to 40% due to bulking. (COVER THE SAND.)

The ASTM standards cited in the narrative box at the bottom of the page reiterate the importance of accurately proportioning the materials that comprise the mortar mixture. It is only possible to consistently and accurately measure the volumetric sand proportion that goes into the mortar mix if the moisture content of the sand is controlled. (COVER THE SAND.)

All the ASTM standards noted in this technical BLAST are part of the masonry code and the International Building Code (IBC), either directly or by reference. (COVER THE SAND.)

ASTM C270, Section 7.1 Storage of materials. Cementitious materials and aggregates shall be stored in such a manner as to prevent deterioration or intrusion of foreign material.

ASTM C 780 Section 11.1.1 Use masonry sand in the damp, as-received condition, and handle in such a manner as to prevent segregation.

ASTM C 1586 Section 5.4 Inspection – Verify by observation the method of measuring material quantities for the mortar used in construction so that it accurately maintains the required proportions.

For more information or further enthusiastic discourse on topics of CODE, please contact Alan Tuck at: [email protected] or 540.344.7939.