Alabama Masonry Contractor

Key Concepts

Reading Construction Drawings - Floor plans show horizontal cuts through a building viewed from above; they indicate wall locations, openings, and dimensions. - Elevations show exterior or interior wall faces; critical for identifying masonry coursing, bond patterns, and opening heights. - Sections show vertical cuts through a structure; reveal wall thickness, footing depth, and masonry assembly layers. - Details are large-scale drawings showing specific conditions (lintels, ties, flashing locations, control joints).

Drawing Scales - Common architectural scales: 1/4" = 1'-0", 1/8" = 1'-0", 1" = 1'-0" - To convert scaled measurement to actual: multiply measured drawing dimension by the scale factor. - Example: A wall measuring 2" on a 1/4" = 1'-0" drawing → 2 ÷ 0.25 = 8 feet actual - Engineering scales (1:10, 1:20, 1:50) appear on civil/site drawings.

(19 questions, 32% of exam)

Key Concepts

Masonry Materials

• Brick is classified by grade (SW, MW, NW) based on weathering exposure. SW (Severe Weathering) is required for below-grade and high-exposure applications.
• CMU (Concrete Masonry Units) are classified as hollow (≥25% void) or solid (<25% void). Standard CMU is 8"×8"×16" nominal.
• Clay tile types include structural clay tile (load-bearing) and non-load-bearing partition tile — know the difference.

Mortar Types (ASTM C270)

• Type M — Highest strength, used below grade, retaining walls, walks. Compressive strength: 2,500 psi minimum.
• Type S — High strength, used at or below grade, where lateral forces are significant. Min. 1,800 psi.
• Type N — General purpose, above-grade exterior, interior walls. Min. 750 psi.
• Type O — Low strength, interior non-load-bearing only. Min. 350 psi.
• Mortar joints must be 3/8" thick for standard masonry. Joints must be full and properly tooled (concave is most common/weather-resistant).

Key Concepts

Mortar Types (ASTM C270)

Mortar is classified into five types based on strength and application. Memorize this from strongest to weakest: M → S → N → O → K

• Type M (2,500 psi): Highest compressive strength. Use below grade, retaining walls, manholes, foundations — anywhere exposed to severe weather or earth pressure.
• Type S (1,800 psi): High strength + good bond. Use for reinforced masonry, below-grade exterior walls, structures in contact with earth.
• Type N (750 psi): General-purpose, medium strength. Use for above-grade exterior and interior load-bearing walls, chimneys. Most commonly specified.
• Type O (350 psi): Low strength. Use for non-load-bearing interior walls, limited exterior exposure. Do not use in freezing conditions.
• Type K (75 psi): Very low strength. Rarely used; typically only historic preservation.

IBC Section 2103.2.4: Mortar for adhered masonry veneer must conform to ASTM C270 Type N or S.

Key Concepts

Metal Wall Tie Types and Applications

• Rectangular ties: Used in cavity wall construction; connect wythes together across the cavity. Must be embedded at least 1½" into mortar joints.
• Z-ties: Used in solid masonry walls (wythes in contact or close proximity). Not permitted in seismic design categories C and higher.
• Corrugated ties: Sheet metal ties used primarily for masonry veneer over wood or steel stud backing. Limited to 1-story or non-high-wind applications in many jurisdictions.

Masonry Veneer Tie Spacing and Anchorage

Per IBC Chapter 14 (referenced in IBC §2101.2.1): - Maximum tie spacing: 18" vertically × 24" horizontally (one tie per 2.67 sq ft of wall area) - Maximum area per tie: 2.67 sq ft - In high-wind or seismic zones, spacing requirements tighten - Ties must be embedded at least 1½" into the outer wythe mortar bed and have at least ⅝" mortar cover to the outside face

Key Concepts

Classification by Formation (Figure 9-2)

Three categories based on how stone formed:

A stone sample may result from more than one formation process.

Common Building Stones – Key Characteristics (Figure 9-3)

• Granite: Hardest common building stone; takes excellent polish; light-colored (white, gray, pink, green); 156–170 pcf; strength 15,000–30,000 psi
• Limestone: Soft, easily scratched; 147–170 pcf; strength 4,000–20,000 psi; all building uses
• Sandstone: Granular texture; fairly hard if well cemented; 135–155 pcf; all building uses
• Marble: Metamorphic; slightly harder than limestone; takes high polish; 165–178 pcf; strength 10,000–23,000 psi
• Slate: Softer than granite; scratches easily; flat crystal fracture; 170–180 pcf; primary uses: roofing and paving
• Traprock: Igneous; hard/durable but causes rust stains from iron minerals; mainly used as crushed stone

Key Concepts

Trowel Types and Patterns

• Philadelphia pattern: Wider blade holds more mortar; best suited for applying mortar to block
• London pattern: Standard blade; primary trowel for laying brick
• Wide London pattern: Rounded heel places mortar farther forward on blade; versatile — can be used for laying brick or block
• Blade anatomy: narrow end = point; wide end near handle = heel; connected by the shank
• Handle materials: wood (most common), plastic, leather, soft grip; wood handles use a ferrule (metal band) to prevent splitting

Special-Purpose Trowels

• Margin trowel: Rectangular front, V-shaped back; mixes mortar, holds mortar during tuck-pointing, spreads grout
• Pointing trowel: Distinctive pointed tip, V-shaped back; spreads mortar in tight corners; smaller version of a brick trowel
• Tuck pointer: Fills and shapes mortar between bricks; works in tandem with a margin trowel (margin holds, tuck pointer pushes)
• Gauging trowel: Shorter blade; mixes small amounts of mortar, thin set, or other products
• Duck bill (coke) trowel: Finishing **curbs, gutter faces, and…

Key Concepts

Cleaning New Brick Masonry: General Procedures

• Allow mortar to cure before cleaning — typically wait at least 7 days before applying acid cleaners to new masonry.
• Pre-wet the wall thoroughly with clean water before applying any cleaning solution. This prevents acid from being absorbed too deeply into the brick and mortar.
• Always rinse thoroughly with clean water after cleaning to neutralize and flush residue.
• Work from top to bottom to avoid streaking from runoff onto uncleaned surfaces.

Acid Cleaning Methods

• Muriatic (hydrochloric) acid is the most common acid used for brick cleaning.
• Light-colored brick: Use a diluted solution — typically no stronger than 1 part acid to 14–20 parts water — to avoid metallic salt staining and discoloration. Light brick is highly susceptible to iron and manganese staining from acid reactions.
• Dark-colored brick: A stronger solution may be used, but pre-wetting and post-rinsing remain mandatory.
• Acid cleaners must never be used on calcium silicate (sand-lime) brick or glazed brick — acid will…

Key Concepts

Scaffold Safety (Subpart L – §1926.451) - Scaffolds must support their own weight plus 4× the maximum intended load without failure. - Maximum load capacity must be posted and not exceeded. - Scaffolds must be erected, moved, or dismantled only under supervision of a competent person. - Guardrails required on all open sides/ends when scaffold is 10 ft or more above the lower level. - Planking must be secured, extend 6–18 inches beyond supports, and overlap at least 12 inches.

Fall Protection (Subpart M – §1926.502) - Fall protection required at 6 feet for construction workers (including masonry). - Acceptable systems: guardrail systems, safety net systems, or personal fall arrest systems (PFAS). - PFAS must limit free fall to 6 feet and arrest force to 1,800 lbs. - Controlled Access Zones (CAZ) may be used for leading-edge work; must be defined by rope, wire, or tape. - Anchorage points for PFAS must support 5,000 lbs per employee.