MCAA Masonry flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Addendum acknowledgment

A bidder records each addendum number and date on the bid form. An unacknowledged addendum can make the bid nonresponsive even when the price is competitive.

Bid bond amount

A bid bond is commonly 5 to 10 percent of the bid amount and guarantees the bidder will enter the contract if awarded. Performance and payment bonds are usually 100 percent of the contract sum.

Unit price purpose

Unit prices price changed quantities after award. They should be built from labor, material, and equipment rates, not derived by dividing the total bid by the total scope.

Common scope gaps

Scaffolding, hoisting, cleaning, flashing, lintels, grout pumps, temporary heat, and anchors are often assigned to other trades. The contract should state in writing which party provides each.

Material escalation clause

A contract provision that adjusts price when specified material costs move beyond a stated basis, such as per bag of mortar cement or per ton of reinforcement, during a long bid-to-build gap.

Alternates pricing order

Price the base bid first, then add or deduct alternates in the order the bid documents list them. Out-of-order alternates can produce a nonresponsive or miscompared bid.

TMS 402 and TMS 602

TMS 402 contains structural design requirements for masonry, including allowable stress and strength design. TMS 602 contains construction and materials requirements. Both are adopted through the building code.

Mortar type selection

Type M has the highest compressive strength, S is for general structural use, N for general use, O and K for low strength. Mortar is specified by type under ASTM C270.

Grout coarse versus fine

ASTM C476 grout is coarse when the clear grout space is 2 inches or more, and fine when the space is 2 to 4 inches. Grout is not mortar.

Prism testing ASTM C1314

Prisms built from the project units and mortar are tested to establish f'm. Prism strength is lower than unit strength, so design values come from prism or correlated values.

Weep hole spacing

Weep holes at the base of a cavity wall allow water to drain. They are placed above flashing and spaced per the specification, commonly no more than 24 inches on center.

Empirical design limits

TMS 402 empirical design applies to single-wythe hollow or solid walls within height and slenderness limits, with minimum f'm of 1,500 psi and mortar type M or S.

Fire resistance equivalent thickness

Masonry fire ratings depend on equivalent thickness, unit type, and whether cores are grouted or filled. Ratings are determined from TMS tables or ASTM E119 testing.

Bid shopping defined

Soliciting a lower price from a subcontractor after using that sub's number to win the prime contract. It is an ethics violation; award goes to the listed sub absent documented cause.

Written change order rule

No extra work proceeds without written authorization or a written directive. Verbal instructions are confirmed in writing the same day with scope, cost, and time impact stated.

Pay-if-paid versus pay-when-paid

Pay-if-paid makes owner payment a condition precedent to subcontractor payment. Pay-when-paid sets a timing obligation. The two clauses have different legal effects and should be identified in the subcontract.

Mechanic's lien deadline

Lien and preliminary notice deadlines run from first furnishing of labor or material, not from project completion. Missing the statutory deadline can forfeit lien rights.

Conflict of interest disclosure

Ownership, family, or financial relationships with suppliers, inspectors, or competing bidders must be disclosed. Undisclosed relationships can void an award and create legal liability.

Substitution documentation

A proposed product substitution requires written approval and documented equivalence to the specified product. Submitting a noncompliant product shifts risk to the contractor.

ASTM C90 versus C129

ASTM C90 covers loadbearing concrete masonry units. ASTM C129 covers nonloadbearing units. The units are not interchangeable, so the correct standard must be specified.

Brick weathering grades

Facing brick grades are SW for severe weathering, MW for moderate, and NW for negligible. Grade selection must match the exposure condition, not only the desired appearance.

Mortar cement versus portland

Mortar cement and masonry cement under ASTM C91 and C1329 are distinct from portland cement-lime mortar. They are not substituted without an approved mix design.

Wall tie corrosion class

Wire joint reinforcement, ties, and anchors must be galvanized or otherwise protected per ASTM A951 and A153. The coating class is selected for the exposure condition.

Breathable versus film sealer

Penetrating breathable sealers allow vapor transmission. Film-forming sealers can trap moisture and cause spalling, so selection depends on the wall assembly design.

Lintel corrosion protection

Steel lintels and shelf angles must be sized for load and protected against corrosion. The primer or galvanizing must match the exposure, and bearing length must meet the design.

Field mock-up purpose

A mock-up wall panel establishes workmanship standards for tooling, joint width, flashing, and cleaning before production. It is approved before the work proceeds.

Mortar sampling ASTM C780

ASTM C780 sets procedures for sampling and testing mortar. Test frequency is set by the specification, and results are compared with the specified compressive strength.

Concealed work inspection

Reinforcement placement, grout space cleanliness, flashing laps, weep placement, and anchor embedment are verified before grouting. These items cannot be inspected after concealment.

Grout consolidation

TMS 602 requires grout consolidation by mechanical vibrator or puddling. Lift height limits depend on grout type, and conventional grout in tall lifts requires reconsolidation.

Water penetration ASTM E514

ASTM E514 water penetration testing on mock-ups or field panels is a common exterior wall quality requirement. Results guide flashing and detailing corrections.

Fall protection threshold

OSHA 1926 Subpart M requires fall protection at 6 feet or more in construction. Options include guardrails, personal fall arrest, or a fall protection plan.

Silica Table 1 controls

OSHA 1926.1153 Table 1 assigns engineering controls by task. Wet cutting, integrated water delivery, and dust collection are specified, with respiratory protection following the table.