MCAA Masonry cheat sheet

Bid documents control: drawings, specifications, addenda, and the invitation to bid form the contract basis; a qualified bid notes exceptions in writing before submission, since silence is treated as acceptance of all terms.

Quantity takeoff for unit-price masonry: count units by wall area minus openings, add 5-10% waste for standard block, more for cut-up work; mortar and grout are estimated per volume of masonry, not per unit.

Bond requirement decision rule: bid bond typically 5-10% of bid; performance and payment bonds typically 100% of contract sum; verify whether the owner requires bonds before pricing them into overhead.

Escalation clause: on projects bid months before construction, state a unit price basis (per 1,000 brick, per ton of reinforcement, per bag of mortar cement) so material price swings are shared per the contract, not absorbed silently.

Addenda acknowledgment: every addendum must be listed by number and date on the bid form; an unacknowledged addendum can render a bid nonresponsive regardless of price.

Alternates and unit prices: price base bid first, then deduct/add alternates in the order listed; unit prices apply to changed quantities and should be built from labor, material, and equipment rates, not from the total bid divided by scope.

Scope gap checklist: scaffolding, hoisting, cleaning, flashing, lintels, grout pumps, temporary heat, and masonry anchors are commonly assigned to other trades; confirm in writing which party provides each.

Bid validity period: 30-60 days is common; a bid held open longer should carry a stated escalation or withdrawal right, because labor and material pricing cannot be guaranteed indefinitely.

TMS 402/602 govern masonry design and construction; TMS 402 covers structural design (allowable stress and strength design), TMS 602 covers construction and materials requirements; the MSJC documents are adopted through the building code.

Empirical design limits (TMS 402 Chapter 5): applies to single-wythe hollow or solid walls, limited height and slenderness, minimum specified compressive strength f'm of 1,500 psi, and minimum mortar type M or S.

Mortar types: M highest compressive strength, S general structural use, N general use, O low strength, K lowest; mortar is specified by type and by ASTM C270, and field-mixed mortar proportions must match the property or proportion specification.

Grout must meet ASTM C476; coarse grout for spaces with clear width of 2 in or more, fine grout for spaces 2 to 4 in wide; grout lift height and consolidation requirements depend on whether it is self-consolidating or conventional.

Masonry prism testing per ASTM C1314 establishes f'm; the compressive strength of a prism is lower than the unit strength, so design values are based on prism or unit-strength correlations, not on the block's individual strength alone.

Reinforcement and anchorage: deformed bars in masonry must comply with ASTM A615 or A706; lap splices and development lengths are set by TMS 402 and depend on bar size, grout cover, and masonry strength.

Flashing and weep requirements: flashing must be corrosion-resistant and lapped, with weep holes at the base of cavity walls spaced per code and specification, typically 24 in on center maximum.

Fire resistance ratings: masonry assemblies achieve ratings through TMS 402/TMS 602 tables and ASTM E119 testing; the rating depends on equivalent thickness, unit type, and whether the core is grouted or filled.

Bid shopping: soliciting a lower price from a subcontractor after using that sub's number to win the prime contract is an ethics violation; the accepted practice is to award to the listed sub absent a documented reason.

Change order discipline: no extra work without written authorization or a written directive; verbal instructions should be confirmed in writing the same day, stating scope, cost, and time impact.

Retainage and prompt payment: retainage is typically 5-10% until substantial completion; payment terms should be stated in the subcontract, and pay-when-paid versus pay-if-paid clauses have different legal effects and should be identified.

Conflict of interest: disclose any ownership, family, or financial relationship with suppliers, inspectors, or competing bidders; undisclosed relationships can void awards and create liability.

Lien rights: file preliminary notices and mechanic's lien notices within the statutory deadline for the jurisdiction, and track the deadline from first furnishing labor or material, not from project completion.

Record keeping: retain daily reports, delivery tickets, test reports, RFIs, and correspondence for the period required by contract and statute; these records are the evidence base for change orders, claims, and warranty disputes.

Submittal honesty: product substitutions require written approval and documented equivalence; submitting a noncompliant product and relying on the reviewer to catch it shifts risk to the contractor.

Safety and schedule commitments are contractual: promising a schedule or safety performance the firm cannot meet to win work is a misrepresentation, and it exposes the firm to delay and safety liability.

Concrete masonry units (ASTM C90): loadbearing units; ASTM C129 covers nonloadbearing units; ASTM C1633 covers crack control units; specify the correct standard, because units are not interchangeable.

Clay brick (ASTM C216 for facing brick, ASTM C652 for hollow brick): grades are SW (severe weathering), MW (moderate), and NW (negligible); grade selection must match the exposure condition, not just appearance.

Mortar cement and masonry cement (ASTM C91, ASTM C1329) are distinct from portland cement-lime mortar; do not substitute one for the other without an approved mix design.

Grout (ASTM C476) is a high-slump mixture of cementitious material, aggregate, and water; it is placed in reinforced and ungrouted cores and is not the same as mortar.

Anchors and ties (ASTM A951, A153): wire joint reinforcement, wall ties, and anchors must be hot-dip galvanized or otherwise protected per the exposure; corrosion protection is specified by coating class.

Flashing materials: through-wall flashing must be durable and compatible with adjacent materials; copper, stainless steel, and PVC are common, and bituminous products should not contact materials they can stain or degrade.

Water repellents and sealers: breathable penetrating sealers allow vapor transmission; film-forming sealers can trap moisture and cause spalling, so selection depends on the wall assembly design.

Lintels and shelf angles: steel lintels must be sized for load and protected against corrosion; the specified primer or galvanizing must match the exposure, and bearing length must meet the design.

Preconstruction mock-up: a field mock-up of a representative wall panel establishes workmanship standards for tooling, joint width, flashing, and cleaning before production begins.

Mortar and grout testing: sample per ASTM C780 for mortar and ASTM C1019 for grout; test frequency is set by the specification, and results are compared with the specified compressive strength.

Prism testing per ASTM C1314 verifies f'm; prisms must be built from the same units and mortar as the work and cured under the specified conditions.

Inspection checkpoints: verify reinforcement placement, grout space cleanliness, flashing laps, weep placement, and anchor embedment before grouting, because these items are concealed afterward.

Grout placement: consolidate grout with a mechanical vibrator or puddling per TMS 602; lift height limits depend on grout type, and reconsolidation is required for conventional grout in tall lifts.

Dimensional tolerances: TMS 602 sets tolerances for plumb, level, and alignment; record deviations against the standard rather than against a subjective judgment.

Water penetration testing per ASTM E514 on mock-ups or field panels is a common QA requirement for exterior walls; results guide flashing and detailing corrections.

Punch list and closeout: document nonconforming work with photos and location, track correction to closure, and assemble test reports, warranties, and as-built records before final payment.

Scaffold requirements: supported scaffolds must be designed and erected per OSHA 1926 Subpart L, with a competent person inspecting before each shift and after any event that could affect stability.

Fall protection: OSHA 1926 Subpart M requires fall protection at 6 ft or more in construction; guardrails, personal fall arrest, or a fall protection plan are the options, and masonry walls under construction are not a substitute for a guardrail system.

Silica exposure: OSHA 1926.1153 Table 1 assigns engineering controls by task; wet cutting, integrated water delivery, and dust collection are the specified controls, and respiratory protection follows the table or an exposure assessment.

Material handling: mortar and block are heavy; mechanical lifting, team lifting, and rotation reduce musculoskeletal injury, and block should not be stacked above the rated capacity of a scaffold platform.

Crane and hoisting: rigging must be inspected, loads must be secured, and no worker may stand under a suspended load; signal persons must be qualified.

Electrical: temporary power on masonry sites requires GFCI protection, and cords and tools must be inspected for damage; water and wet mortar increase shock risk.

Hazard communication: silica, mortar, and sealers require SDS access and training; cement is a skin sensitizer, so gloves and washing facilities are required controls.

Excavation and wall stability: unbraced masonry walls under construction can collapse in wind; temporary bracing and no-work zones near tall unbraced walls are standard controls.