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Chapter 7 Masonry
Materials, construction methods, quantity takeoff, and estimating for brick, CMU, stone, and mortar systems in building construction.
Masonry Unit Materials
Brick, structural clay tile, CMUs, special materials, and mortar classification
Masonry units include brick, structural clay tile, and concrete masonry units (CMUs). They come in many shapes, sizes, and materials — clay, concrete, or glass. Masonry units are joined with mortar and may be reinforced with steel. They are fire-resistant and commonly used as firebreaks between adjoining areas.
Masonry is noted in Division 4 of the CSI MasterFormat™. All masonry materials, accessories, and specifications are organized under this division for estimating purposes.
Brick Types
A brick is a masonry unit made of clay or shale formed into a rectangular shape while soft, then fired in a kiln. Most brick is packaged on pallets of 250 units. Specifications and exterior elevations provide brick type and design information.
Building Brick (Common Brick)
Made from local clay or shale. Types include Standard Modular, Norman, SCR, Engineer, and Economy. The nominal dimensions of modular bricks are based on a 4″ unit including mortar joints.
- Norman: Longer than standard (12″ nominal length)
- SCR: Thicker (6″ nominal thickness), allows single-wythe walls
- Engineer: Greater height (3⅛″ nominal), standard thickness/length
- Economy: Available in full 4″ modules for rough-work applications
Face Brick
Made of select clay to impart distinctive, uniform colors. Used for exposed, finished surfaces. Manufacturing creates uniform hardness, size, and strength for a quality finish. Available in many colors and shapes.
Firebrick
Manufactured from refractory ceramic materials that resist disintegration at high temperatures. Used in areas subjected to high temperatures — fireplace hearths, industrial furnace linings, and chimney fireboxes.
Glass Block
Hollow translucent or transparent block made of glass. Available in many sizes and colors. Cannot be used in load-bearing applications. Used for decorative and light-transmitting applications.
Building Brick Dimensions Reference
* All dimensions in inches. Actual dimensions are ⅜″ to ½″ less than nominal (mortar joint included in nominal).
Structural Clay Tile
A structural clay tile is a hollow masonry unit composed of burned clay, shale, or a combination. Glazed and unglazed tiles are used for structural and decorative applications. Shapes include stretchers, sills, caps, miters, corners, jambs, and cove bases. Used as a structural back-up material in older buildings and for interior construction in high-wear areas like restaurant kitchens and public restrooms.
Concrete Masonry Units (CMUs)
A CMU is a precast hollow or solid block made of portland cement and fine aggregate. Actual dimensions are ⅜″ to ½″ less than nominal size. CMUs possess excellent fire-resistance qualities and are commonly used for firebreaks. CMU shapes include:
Special Masonry Materials
Include flue liners and refractory brick manufactured in standard sizes. Availability is dependent on local suppliers. Used in fireplaces and furnace/boiler flues. Noted in specs under MasterFormat title 04 05 00.
Vertical or horizontal joints without mortar or nonresilient materials. Include expansion joints and control joints. Locations shown on elevations and detail drawings. Rods covered by polyurethane/silicone sealant fill these joints.
Typically consists of steel wire shaped into patterns and set in mortar joints. A tie secures two or more members together — embedded in joints to tie masonry walls together or anchor veneer walls to backing.
Attached to inner wall surface, terminates at a weep hole. The weep hole may be open or filled with materials allowing moisture to escape (wicks, weep tubes, cellular vents). Prevents moisture penetration at exposed wall surfaces.
Attached to structural backing members using lag bolts or other attachment specified by architect. Used to support horizontal courses of brick for high masonry walls.
Polyurethane sealants for porous and porous-to-nonporous materials. Silicone sealants for nonporous materials. Caulked into movement joints to allow movement while sealing the joint. Noted in specifications and exterior elevations.
Mortar Types & Classification
Mortar is a bonding mixture of fine aggregate, cement, and water used to fill voids between masonry units, join them, and reinforce the structure. Classified as Type M, S, N, O, and K.
Type N mortar is the most common type specified for construction projects. Type M has the highest cement content and highest compressive strength (~2,500 psi) but highest shrinkage. An estimator must ensure the proper amount, type, and color of mortar is taken off for each masonry application.
Masonry Unit Construction Methods
Equipment, wall types, bonds, fireplaces, and SAM technology
Construction methods depend on design, materials used, structure height, environmental conditions, and interior finishes. Walls may be hollow, solid, a veneer covering a structural member, or prelaid curtain walls. Masonry units are commonly used with wood/metal framing, structural steel, or concrete.
Equipment Required
Masonry Construction Equipment
- Rough-terrain forklifts / telehandlers: Move pallets of brick and CMUs at job site
- Mortar mixers: Mix batches of mortar
- Scaffolds: Traditional sectional metal-framed or hydraulic mast-climbing types
- Weather protection: Required in cold climates to allow mortar to set properly
- Temporary bracing: For high, unsupported walls until roof members are set
Three Main Types of Masonry Walls
- Masonry materials only, reinforced with metal ties
- Formed of one or two layers of brick tied together
- Metal ties connect brick to CMUs, or CMUs only
- Estimator must check architectural details for materials used
- Facing and backing wythes are completely separate
- Minimum 2″ void between facing and backing wythes
- Metal ties join the two wythes into one structural unit
- Air space improves insulation and reduces thermal transmission
- Used in frame, structural steel, and reinforced concrete construction
- Ties anchor masonry veneer to backing wall
- Commonly built in place; also available as prefabricated panels
- Prefab panels use steel support frames, lifted into place
- Similar to masonry veneer but creates an air separation space
- Moisture captured by drainage plane on exterior structural wall face
- Rain/moisture removed by airflow through high vents and weep holes at bottom
- Airflow through separation space creates the rain screen
Brick Bonds
A bond is the arrangement of masonry units in a wall created by overlapping them one over another to provide a sturdy structure. Architects specify a bond and a joint finish. Each bond uses combinations of brick positions.
The brick bond, brick position, and type/size of brick all affect the cost of a masonry job. It is crucial to review building elevations, specifications, and details when estimating brick masonry.
Brick Positions
Construction Process
How a Masonry Wall is Built
- Begins on a solid foundation of cast-in-place concrete (footing, wall, or thickened slab)
- Steel dowels cast in concrete tie masonry and concrete together
- Corner masonry units are set first in mortar; work proceeds from each corner
- A course is a continuous horizontal layer of masonry units bonded with mortar
- Mason’s rule or story pole lays out proper brick/CMU spacing
- Strings stretched between story poles guide masonry work
- Mortar joints struck as work proceeds to create joint profile
- Muriatic acid and water used after mortar sets to remove excess mortar
Semi-Automated Masons (SAMs)
A human mason can install 300–500 bricks per day. A SAM (Semi-Automated Mason) is capable of installing 800–1,200 bricks per day. A SAM still requires a human mason to do finish work such as striking masonry joints. SAMs handle initial lifting, setting, and placing while brickmasons strike mortar joints for quality.
Fireplaces
All combustible materials must have a minimum clearance of 2″ from front faces and sides, and not less than 4″ clearance from the back faces of a masonry fireplace. The inner hearth is laid first using firebrick with refractory mortar. A smoke shelf is a section of chimney directly over the fireplace and below the flue liner — it prevents downdrafts. Two types of refractory mortar are permitted by ICC: hydraulic-setting mortar and air-drying mortar.
Masonry Material Quantity Takeoff
Calculating brick, CMU, and mortar quantities with calculators
When estimating masonry materials, an estimator typically performs the takeoff from the bottom of the structure up and from the outside in. Begin with the foundation and above-grade exterior walls. After exterior materials, compute interior masonry (fireplaces, interior walls, hearths).
Base masonry material costs on the delivered cost of materials. Preliminary work (excavation, concrete footings) must be performed before masonry begins. Equipment costs, scaffold, weather protection, and contingency costs must all be included in the masonry bid.
Masonry Wall Takeoff Steps
Step-by-Step Takeoff Process
- Step 1: Compute gross surface area of exterior walls (length × height)
- Step 2: Deduct openings (doors, windows) to get net surface area — waste factors are 2%–5% for masonry units, 10%–20% for mortar
- Step 3: Apply multiplier from masonry wall material table to get number of units
- Step 4: Add waste factor after net surface area calculations are complete
- Step 5: For CMUs: divide wall length by CMU length, then multiply by number of courses
Formula Reference
Labor Costs
Labor costs for masonry construction are typically based on square foot of masonry surface area. Standard labor tables or company historical data provide information about square feet of surface area set in place by a particular labor crew per hour. Labor hours multiplied by cost per crew-hour determines overall labor costs.
A human mason can install 300–500 bricks a day. A SAM is capable of installing 800–1,200 bricks a day. When SAMs are utilized, machinery costs and labor costs are closely aligned — based on square feet of masonry surface area including owning, maintaining, transporting, and programming the robotic equipment.
Fireplace & Chimney Takeoff
Fireplace Surface Calculation Method
- Calculate all surfaces of a fireplace as solid areas
- Multiply surface area by layers/tiers of brick deep
- Face brick may be backed by interior wall, face brick, or common brick
- For chimneys: determine linear distance around chimney × height above roofline = square feet of chimney
- Standard ledger sheet method: calculate cubic feet of chimney/fireplace, deduct flue lining and hearth areas
- Add square feet of firebrick required for combustion chamber separately
Small Chimney Brick Reference
Practice Problems
- Compute gross surface area of one wall (length × height)
- Compute gross area of all four walls
- Compute opening area (width × height × number of doors)
- Compute net wall area (gross − openings)
- Apply multiplier for face bricks and building bricks
Area one wall: 24.5′ × 10′ = 245 sq ft
Area four walls: 245 × 4 = 980 sq ft
Opening area: 9′ × 8′ × 2 = 144 sq ft
Net area: 980 − 144 = 836 sq ft
Face bricks: 836 × 7.04 = 5,885 face bricks
Building bricks: 836 × 5.28 = 4,414 building bricks
- Determine number of CMUs per course: wall length ÷ CMU length
- Determine number of CMU courses: wall height ÷ CMU height
- Total CMUs = CMUs per course × number of courses
CMUs per course: 32′ ÷ 1.33′ = 24 CMUs/course
Number of courses: 7.5′ ÷ 0.67′ = 11 courses
Total CMUs: 24 × 11 = 264 CMUs
Stone
Rock classifications, granite, limestone, marble, slate, and precast stone
Stone is used for many construction applications — veneer, structural, and decorative. Three characteristics affect building stone features: color, pattern, and texture. Stone should be selected based on moisture penetration, weatherability, price, availability, color, pattern, and texture.
The Three Rock Types
Granite: Extremely hard, quartz/feldspar/minerals, produced under intense heat and pressure. White to gray, retains cut shape. Used for building stone, veneer, and decorative purposes.
Traprock: Fine-grained, dark-colored. Commonly used as a base under asphalt pavement.
Limestone: Calcium carbonate, white to light gray, relatively soft. Common applications: lintels, sills, light decorative uses.
Sandstone: Quartz held by silica/iron oxide/calcium carbonate, granular texture, primarily decorative facing.
Marble: Crystallized limestone, slightly harder than limestone. Commonly used as decorative veneer. Available in preshaped squares or panels with highly varied color veins.
Slate: Fine-grained, easily split into thin sheets. Used as roofing tile and flooring material.
Rock Type Comparison
Precast Stone
Precast Stone Advantages
- Concrete cast in molds — wide variety of sizes and shapes
- Consistency of size and structural qualities (unlike natural stone)
- Various face treatments: rough, smooth, grooved, or other surface finishes
- Backs and sides can be designed for interlocking between individual pieces
- Can be designed for solid bonding with mortar
- Styles and sizes vary depending on local material availability and manufacturer designs
Stone Construction Methods
Stone classifications, bonds, placement, and structural applications
Many masonry construction methods used for brick and CMUs also apply to stone. Stone veneer must be placed on a firm footing or against a firm backing material. Equipment may be required to set large-sized stone.
Stone Classifications for Construction
Stone Bonds
- Various sizes of stone in random arrangement
- No courses or ranges maintained
- Broken range bond: random with larger stones breaking the range
- Stone arranged in courses/ranges with vertical joints aligned on alternating rows
- Each course may be a different thickness as long as range remains unbroken
- A range is a course of any thickness extending across the full face of a wall
- Random rubble with approximately squared stones
- Provides more uniform appearance than pure rubble
- Precision-cut ashlar in coursed arrangement
- Broken range created with larger stone pieces
- Highest precision and labor cost
Stone Placement
For structural applications, stone is set with mortar similar to brick and CMUs. Nonstaining cement mortar is used for light-colored stone. Additional metal ties are often required for structural stone applications. Care should be taken to use nonstaining metal ties such as plated steel or zinc. For some applications (low decorative walls, low retaining walls), stone such as limestone may be placed dry without mortar.
Various mastics, mortars, and clips may be used where decorative face-stone panels are fastened to structural members. The estimator should check specifications and details for fastening information pertaining to face stone to determine labor requirements.
Stone Quantity Takeoff
Stone wall costs, veneer walls, quarry costs, and estimating variables
Structural-stone members such as lintels and sills are taken off individually — with length, width, and depth noted. Stone for walls is ordered by the ton. Estimators should consult with potential supplying quarries to determine the number of square feet of surface coverage expected per ton of stone for structural uses.
Stone Wall Cost Factors
Structural Stone Wall Costs
- Similar costs to laying CMUs or brick
- Includes: mortar, transportation, scaffolding, weather protection, temporary bracing
- Square footage calculations equate square footage with unit costs per ton of stone
- Labor prices also based on price per ton from standard industry guides or company historical data
Stone Veneer Wall Estimating
- Based on square foot costs OR per piece costs
- Decorative stone types, thicknesses, locations, and fastening methods all affect material, labor, and equipment costs
- Standard industry information or company historical data for labor-unit production levels
- Quarrying costs
- Quarry location and construction-site location
- Availability of stone required for project
- Stone lintels priced individually and added to spreadsheet/database
- Transportation costs (some stone transported great distances)
Estimators should contact suppliers in the geographic location of a project to check for the availability of stone required. Some stone may need to be transported great distances between the quarry and construction site, adding transportation expenses to the estimate. Estimators should obtain stone costs including delivery and transportation costs to ensure an accurate estimate.
Practice Problems
- Calculate gross wall area: 50 × 9 = 450 sq ft
- Apply waste to material quantity: 450 × 1.05 = 472.5 sq ft of material
- Material cost: 472.5 × $15.00
- Labor cost: 450 × $10.00 (labor on net area)
- Add material + labor for total
Wall area: 50 × 9 = 450 sq ft
Material with waste: 450 × 1.05 = 472.5 sq ft
Material cost: 472.5 × $15.00 = $7,087.50
Labor cost: 450 × $10.00 = $4,500.00
Total cost: $7,087.50 + $4,500.00 = $11,587.50
- Look up bricks per foot of height for 2 flues, 8×12 size from chimney table: 52 bricks/foot
- Alternatively, use perimeter method: perimeter × height = sq ft, then apply brick multiplier
- Using table method: 52 bricks/foot × 6 feet
From small chimney table: 2 flues, 8×12 = 52 bricks/foot
Height above roofline: 6 feet
Total bricks: 52 × 6 = 312 bricks
Chapter 7 Quiz
Test your understanding of masonry materials, methods, and quantity takeoff
Glossary of Key Terms
Chapter 7 masonry vocabulary for estimating and construction
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