Masonry is generally estimated by the piece (brick, block, etc.) or by wall area (per square foot). Quantities based on square feet of surface area are a function of:
- Size of the masonry unit.
- Bond (pattern or coursing).
- Thickness of mortar joints.
- Thickness of wall.
Similar to other Construction Institute Specifications (CSI) divisions, masonry estimates should be performed in as detailed a manner as is practical. The masonry specifications will contain pertinent information which should be noted before proceeding with the quantity takeoff. Such items as mortar types, joint reinforcing, and cleaning requirements should all be described and defined. Required mortar additives (coloring, anti-hydro, bonding agents, etc.) will be specified and should be noted.
It is important that mortar specifications be followed carefully. What little money may be saved by “skimping” on the mortar is not really worth the risks involved. When all requirements in the specifications have been noted, the plans must be carefully reviewed. Drawings and details of masonry work are usually interspersed throughout the plans. All sheets should be checked. Walls and partitions of different masonry types and sizes are estimated separately. Requirements which must be listed and estimated individually include:
- Number and type of masonry units
- Bonding patterns
- Special coursing
- Lintels and accessories
- Joint size (mortar quantities) and finish
- Grouting (cores, pilasters, door jambs, and bond beams, incl. reinforcing)
- Joint reinforcing
Excerpted from Unit Price Estimating Methods, available through RSMeans