Unit Masonry
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 6
to Rev 7
in Unit Masonry.
---
title: Unit Masonry
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| ASTM C140 | Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units |
−# Submittals
+# Submittals {toc}
## Action Submittals {toc}
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```
−# Quality Assurance
+# Quality Assurance {toc}
## Installer Qualifications {toc}
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### The mock-up demonstrates the Contractor's ability to achieve the specified appearance and workmanship and establishes the standard for the Owner's and Architect's review of color, texture, mortar joint profile, joint tooling, and workmanship quality. {note}
−```datasheet
−label: Mock-Up Required
−type: radio
−options:
− - "Yes — construct mock-up panel before production work"
− - "No — waived by Architect"
−default: "Yes — construct mock-up panel before production work"
−```
+### The minimum size of the mock-up panel shall be specified, sufficient to demonstrate the specified appearance and workmanship for review.
```datasheet
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### The Contractor shall construct a mock-up panel before beginning production masonry work.
+```datasheet
+label: Mock-Up Required
+type: radio
+options:
+ - "Yes — construct mock-up panel before production work"
+ - "No — waived by Architect"
+default: "Yes — construct mock-up panel before production work"
+```
+
### The mock-up panel shall be built at the project site using the same materials, equipment, and personnel as will be used in production work.
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### Units failing to meet specified compressive strength minimums shall be rejected and removed from the site.
−# Masonry Units
+# Masonry Units {toc}
## Concrete Masonry Units {toc}
### ASTM C90 covers both hollow and solid units, in any weight classification. {note}
+### The CMU application type, load-bearing or non-load-bearing, shall be specified, confirmed by the structural engineer where non-load-bearing use is claimed.
+
```datasheet
label: CMU Application Type
…5 unchanged lines
```
+### The nominal CMU unit size — width, height, and length — shall be specified for this project.
+
```datasheet
label: CMU Nominal Unit Size (Width × Height × Length)
…72 unchanged lines
### ASTM C216 is the specification for solid clay or shale brick intended to be used as the exposed face of masonry, where appearance quality is required; Grades SW and MW reflect weathering resistance and Types FBS, FBX, and FBA reflect dimensional tolerance and surface appearance. {note}
−```datasheet
−label: Clay Facing Brick Grade
−type: radio
−options:
− - "SW — Severe Weathering (exterior, freeze-thaw exposure)"
− - "MW — Moderate Weathering (interior or low-weathering-index regions)"
−default: "SW — Severe Weathering (exterior, freeze-thaw exposure)"
−```
+### The clay facing brick type shall be specified, consistent with the dimensional tolerance and surface appearance required for the exposed face of the masonry.
```datasheet
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```
+### The clay facing brick color and texture shall be specified, matching the standard established by the approved mock-up panel.
+
```datasheet
label: Clay Facing Brick Color and Texture
…7 unchanged lines
### Grade SW (Severe Weathering) brick shall be used in all exterior applications and wherever brick may be in contact with the ground or subject to water saturation with freezing.
+```datasheet
+label: Clay Facing Brick Grade
+type: radio
+options:
+ - "SW — Severe Weathering (exterior, freeze-thaw exposure)"
+ - "MW — Moderate Weathering (interior or low-weathering-index regions)"
+default: "SW — Severe Weathering (exterior, freeze-thaw exposure)"
+```
+
### Grade MW (Moderate Weathering) brick is only appropriate in regions with a low weathering index and where the brick will not be subjected to repeated freezing while saturated.
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### Units damaged by freezing while wet shall be discarded.
−# Mortar and Grout
+# Mortar and Grout {toc}
## Mortar — General {toc}
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### The four principal mortar types represent a descending scale of compressive strength: Type M is strongest, followed by Type S, Type N, and Type O. {note}
+### The mortar type shall be specified, consistent with the application's location, exposure, loading, and required compressive strength.
+
```datasheet
label: Mortar Type
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```
+### The mortar specification method, proportion or property, shall be specified in accordance with ASTM C270.
+
```datasheet
label: Mortar Specification Method
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### Masonry cement mortars substitute a pre-blended masonry cement complying with ASTM C91 for the portland cement-lime combination, and mortar cement complying with ASTM C1329 is similar to masonry cement but has specified minimum flexural bond strength requirements. {note}
+### The mortar cementitious material system shall be specified, selecting among the portland cement-lime, masonry cement, and mortar cement systems recognized by this standard.
+
```datasheet
label: Mortar Cementitious Material System
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### ASTM C476 provides two classifications — fine grout and coarse grout — and two placing methods — conventional grout (requiring consolidation by puddling or mechanical vibration) and self-consolidating grout (which flows into place without mechanical vibration due to its high fluidity). {note}
+### The grout classification, fine or coarse, shall be specified consistent with the grout space dimension at each masonry application.
+
```datasheet
label: Grout Classification
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```
+### The grout placing method, conventional or self-consolidating, shall be specified, consistent with the grout space dimensions and consolidation access available.
+
```datasheet
label: Grout Placing Method
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```
+### The minimum grout compressive strength, f'g, shall be specified, not less than the minimum established by TMS 602.
+
```datasheet
label: Grout Minimum Compressive Strength f'g
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### TMS 602 Article 3.5D establishes maximum grout pour heights based on grout space dimensions and the grouting method. {note}
+### The maximum single grout pour height shall be specified, consistent with the grout space dimensions and the grouting method used.
+
```datasheet
label: Maximum Single Grout Pour Height
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### The intent of reconsolidation is to close the settlement void that forms as bleed water is absorbed into the masonry and to re-establish intimate contact between the grout and the reinforcement. {note}
−# Reinforcement, Ties, and Anchors
+# Reinforcement, Ties, and Anchors {toc}
## Joint Reinforcement {toc}
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### Ladder-type joint reinforcement consists of two longitudinal wires connected by straight cross wires perpendicular to the wall face, while truss-type uses diagonal cross wires. {note}
−```datasheet
−label: Joint Reinforcement Configuration
−type: radio
−options:
− - "Ladder type — straight cross wires, preferred for grouted CMU"
− - "Truss type — diagonal cross wires, for horizontal shear or crack control"
−drawing_ref: true
−default: "Ladder type — straight cross wires, preferred for grouted CMU"
−```
+### The joint reinforcement wire diameter shall be specified, not less than the minimum required by TMS 402 for the application.
```datasheet
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### Joint reinforcement shall comply with ASTM A951, Standard Specification for Steel Wire for Masonry Joint Reinforcement, and shall be of the truss or ladder configuration as indicated on the contract documents.
+```datasheet
+label: Joint Reinforcement Configuration
+type: radio
+options:
+ - "Ladder type — straight cross wires, preferred for grouted CMU"
+ - "Truss type — diagonal cross wires, for horizontal shear or crack control"
+drawing_ref: true
+default: "Ladder type — straight cross wires, preferred for grouted CMU"
+```
+
### Ladder-type is preferred for walls with open vertical cells because the straight cross wires do not obstruct grout flow, while truss-type has greater shear stiffness in the horizontal plane. {note}
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### Anchors connect masonry wythes to a structural frame member. {note}
+### Wall ties shall be fabricated from steel sheet conforming to ASTM A1008, from steel wire, or from stainless steel as required by the corrosion exposure.
+
```datasheet
+label: Wall Tie Corrosion Protection
+type: radio
+options:
+ - "Hot-dip galvanized per ASTM A153 Class B (exterior walls)"
+ - "Stainless steel ASTM A580 or A240 (severe exposure, coastal, high chloride)"
+ - "Mill galvanized (interior, protected exposure only)"
+default: "Hot-dip galvanized per ASTM A153 Class B (exterior walls)"
+```
+
+### Adjustable two-piece ties provide vertical adjustment to accommodate differential movement and construction tolerances, while fixed ties shall only be used where adjustment is not required and the differential movement between backup and veneer is negligible.
+
+```datasheet
label: Wall Tie Type
type: radio
…7 unchanged lines
```
−```datasheet
−label: Wall Tie Corrosion Protection
−type: radio
−options:
− - "Hot-dip galvanized per ASTM A153 Class B (exterior walls)"
− - "Stainless steel ASTM A580 or A240 (severe exposure, coastal, high chloride)"
− - "Mill galvanized (interior, protected exposure only)"
−default: "Hot-dip galvanized per ASTM A153 Class B (exterior walls)"
−```
+### Wall ties for masonry veneer shall be spaced at a maximum of one tie per 2.67 sq ft of wall area, with maximum horizontal spacing of 36 in. and maximum vertical spacing of 24 in.
```datasheet
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min: 12
max: 36
− setpoints: [16, 24, 32, 36]
+ setpoints: [12, 16, 24, 32, 36]
drawing_ref: true
default: 24
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```
−### Wall ties shall be fabricated from steel sheet conforming to ASTM A1008, from steel wire, or from stainless steel as required by the corrosion exposure.
−
−### Adjustable two-piece ties provide vertical adjustment to accommodate differential movement and construction tolerances, while fixed ties shall only be used where adjustment is not required and the differential movement between backup and veneer is negligible.
−
−### Wall ties for masonry veneer shall be spaced at a maximum of one tie per 2.67 sq ft of wall area, with maximum horizontal spacing of 36 in. and maximum vertical spacing of 24 in.
−
### In Seismic Design Categories C through F, or where indicated on the structural drawings, tie spacing shall be reduced and tie type shall be as required by TMS 402.
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### Ties shall not bridge a cavity where the cavity is a designed drainage space.
−# Accessories — Flashing, Weeps, and Movement Joints
+# Accessories — Flashing, Weeps, and Movement Joints {toc}
## Through-Wall Flashing {toc}
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### Weep holes provide the drainage outlet for water intercepted by through-wall flashing. {note}
−```datasheet
−label: Weep Hole Type
−type: radio
−options:
− - "Open head joint — head mortar omitted at weep locations"
− - "Plastic tube weep (cotton wick type) — for aesthetic reasons where open head joint is objectionable"
− - "Plastic louvered vent weep — insect screen, louvered"
−default: "Open head joint — head mortar omitted at weep locations"
−```
+### Weeps shall be located at the mortar bed joint immediately above the flashing at head joint locations.
+### The maximum spacing of weep holes shall be 24 in. o.c., with open head joint weeps having a minimum clear opening of 3/4 in. wide and full-joint height.
+
```datasheet
label: Weep Hole Spacing (Maximum)
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```
−### Weeps shall be located at the mortar bed joint immediately above the flashing at head joint locations.
−
−### The maximum spacing of weep holes shall be 24 in. o.c., with open head joint weeps having a minimum clear opening of 3/4 in. wide and full-joint height.
−
### Screens or plastic weep inserts shall be set in the joint and shall not block the drainage opening, and louvered plastic inserts shall be confirmed to be open to drainage and not merely ornamental.
+```datasheet
+label: Weep Hole Type
+type: radio
+options:
+ - "Open head joint — head mortar omitted at weep locations"
+ - "Plastic tube weep (cotton wick type) — for aesthetic reasons where open head joint is objectionable"
+ - "Plastic louvered vent weep — insect screen, louvered"
+default: "Open head joint — head mortar omitted at weep locations"
+```
+
### Weep holes shall be kept free and clear at all times during and after construction.
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### Control joints are intentional vertical discontinuities that concentrate movement at planned locations, keeping the field masonry crack-free between joints. {note}
+### Control joints in CMU walls shall be provided at vertical locations shown on the structural and architectural drawings.
+
+### Where joint locations are not fully detailed, the Contractor shall install control joints at the following maximum intervals unless directed otherwise by the Engineer of Record: in exterior unreinforced or lightly reinforced CMU walls, control joint spacing shall not exceed 25 feet, and at returns, openings, and changes in wall height, control joints shall be located within 4 feet of the discontinuity.
+
```datasheet
label: Control Joint Spacing (Maximum, CMU)
…4 unchanged lines
min: 12
max: 40
− setpoints: [16, 20, 25, 30]
+ setpoints: [12, 16, 20, 25, 30, 40]
default: 25
```
−### Control joints in CMU walls shall be provided at vertical locations shown on the structural and architectural drawings.
−
−### Where joint locations are not fully detailed, the Contractor shall install control joints at the following maximum intervals unless directed otherwise by the Engineer of Record: in exterior unreinforced or lightly reinforced CMU walls, control joint spacing shall not exceed 25 feet, and at returns, openings, and changes in wall height, control joints shall be located within 4 feet of the discontinuity.
−
### At intersecting wall conditions, control joint placement shall be coordinated with the structural engineer to preserve load paths.
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### Expansion joints in clay brick veneer allow the masonry to expand without developing compressive stress that would otherwise bow or crack the wall. {note}
+### Expansion joints in clay brick veneer shall be provided at vertical locations shown on the drawings.
+
+### In unreinforced clay brick veneer on multi-story buildings, expansion joint spacing shall generally not exceed 25 feet horizontally and shall be provided at every floor line where the veneer bears on a shelf angle.
+
```datasheet
label: Expansion Joint Spacing (Maximum, Clay Brick)
…4 unchanged lines
min: 12
max: 30
− setpoints: [16, 20, 25, 30]
+ setpoints: [12, 16, 20, 25, 30]
default: 25
```
−### Expansion joints in clay brick veneer shall be provided at vertical locations shown on the drawings.
−
−### In unreinforced clay brick veneer on multi-story buildings, expansion joint spacing shall generally not exceed 25 feet horizontally and shall be provided at every floor line where the veneer bears on a shelf angle.
−
### Expansion joints shall also be provided at returns, at changes in wall direction, and at major re-entrant corners.
−### Unlike control joints in CMU, which accommodate shrinkage and must be filled with a compressible sealant, expansion joints in brick must remain free of all rigid material so that the expanding brick has room to move. {note}
+### Unlike control joints in CMU, which accommodate shrinkage and must be filled with a compressible sealant, expansion joints in brick must remain free of all rigid material so that the expanding brick has room to move.
### No mortar, grout, or hardened filler shall be placed in a brick expansion joint.
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### The backer rod limits sealant depth to approximately 50 percent of joint width and prevents three-sided adhesion, which would prevent the sealant from performing its two-sided elongation function. {note}
−# Environmental and Service Conditions
+# Environmental and Service Conditions {toc}
## Cold Weather Masonry Construction {toc}
…2 unchanged lines
### The following temperature thresholds define required protection levels in accordance with TMS 602 Article 1.8C and accepted industry practice. {note}
+### Mortar that freezes before reaching a compressive strength of approximately 500 psi will suffer permanent strength loss and bond failure due to ice crystal formation in the mortar matrix. {note}
+
+### Cold weather procedures shall be implemented whenever the ambient temperature is below 40°F or is forecast to drop below 40°F within 24 hours.
+
```datasheet
label: Cold Weather Protection Plan
…6 unchanged lines
```
−### Mortar that freezes before reaching a compressive strength of approximately 500 psi will suffer permanent strength loss and bond failure due to ice crystal formation in the mortar matrix. {note}
−
−### Cold weather procedures shall be implemented whenever the ambient temperature is below 40°F or is forecast to drop below 40°F within 24 hours.
−
### When the ambient temperature is between 40°F and 32°F, mortar and grout shall be heated to provide a temperature between 40°F and 120°F at the time of placement, all materials, mixing water, and mixing equipment shall be protected from freezing, and completed masonry shall be covered with weather-resistant membrane for 24 hours after construction.
…40 unchanged lines
### The service environment determines the appropriate unit grade, mortar type, and protection level for the masonry assembly. {note}
−### At-grade and below-grade applications in contact with soil, and all-weather exterior applications, require the highest durability; above-grade exterior protected applications allow Grade MW brick, standard ASTM C90 units, and Type N mortar; and interior protected applications not subject to moisture have the widest range of acceptable materials. {note}
+### At-grade and below-grade applications in contact with soil, and all-weather exterior applications, require the highest durability; above-grade exterior protected applications allow Grade MW brick, standard ASTM C90 units, and Type N mortar; and interior protected applications not subject to moisture have the widest range of acceptable materials.
```datasheet
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```
−# Installation
+# Installation {toc}
## Layout and Coursing {toc}
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### Where the structural engineer has identified shelf angles as carrying significant loads, installation shall be coordinated with the structural steel subcontractor and verified before masonry above is placed.
−# Field Testing and Quality Control
+# Field Testing and Quality Control {toc}
## Masonry Prism Testing {toc}
### Prism testing is the most direct method of verifying the combined performance of the unit, mortar, and grouting system as an assembly. {note}
+### Where specified compressive strength of masonry (f'm) is indicated on the contract documents, verification of f'm shall be by masonry prism testing in accordance with ASTM C1314, Standard Test Method for Compressive Strength of Masonry Prisms.
+
```datasheet
label: Masonry Prism Testing Required
…19 unchanged lines
```
+### Prisms shall be constructed by the Contractor in the presence of the Special Inspector from the same units, mortar, and grout used in the production work, using the same laying procedure.
+
+### Prisms shall consist of a minimum of three masonry units in height.
+
+### Prisms shall be transported to the laboratory without damage and tested at 28 days, unless the specifying engineer approves earlier testing with an age factor.
+
+### At least three prisms per masonry wythe per set shall be tested, with the average strength representing the lot.
+
```datasheet
label: Prism Test Frequency
…7 unchanged lines
```
−### Where specified compressive strength of masonry (f'm) is indicated on the contract documents, verification of f'm shall be by masonry prism testing in accordance with ASTM C1314, Standard Test Method for Compressive Strength of Masonry Prisms.
−
−### Prisms shall be constructed by the Contractor in the presence of the Special Inspector from the same units, mortar, and grout used in the production work, using the same laying procedure.
−
−### Prisms shall consist of a minimum of three masonry units in height.
−
−### Prisms shall be transported to the laboratory without damage and tested at 28 days, unless the specifying engineer approves earlier testing with an age factor.
−
−### At least three prisms per masonry wythe per set shall be tested, with the average strength representing the lot.
−
### If the prism test result is below f'm, the Contractor shall notify the structural engineer immediately.
…6 unchanged lines
### Preconstruction mortar tests using the mix proportions and materials proposed for the project establish the baseline properties. {note}
+### Mortar sampling and testing shall be performed in accordance with ASTM C780, Standard Test Method for Preconstruction and Construction Evaluation of Mortars.
+
+### During construction, periodic samples shall be taken from the mortar board and tested for compressive strength and water retention.
+
+### Mortar samples shall be taken from a representative location on the mortar board after the mortar has been spread but before units are laid.
+
+### Mortar samples shall be taken at the rate of at least one per each 5,000 sq ft of masonry wall area, or as directed by the Special Inspector.
+
```datasheet
label: Mortar Sampling Frequency
…7 unchanged lines
```
−### Mortar sampling and testing shall be performed in accordance with ASTM C780, Standard Test Method for Preconstruction and Construction Evaluation of Mortars.
−
−### During construction, periodic samples shall be taken from the mortar board and tested for compressive strength and water retention.
−
−### Mortar samples shall be taken from a representative location on the mortar board after the mortar has been spread but before units are laid.
−
−### Mortar samples shall be taken at the rate of at least one per each 5,000 sq ft of masonry wall area, or as directed by the Special Inspector.
−
### Mortar sampled from the mortar board does not represent the hardened mortar in the joint, because the mortar in the joint loses water to the units and achieves higher strength. {note}
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### The Special Inspector shall observe the slump of each grout delivery, that cells to be grouted are clean, that reinforcement is properly positioned, that lift heights and consolidation procedures comply with the approved grouting procedure, and that reconsolidation is performed within the specified time window.
−# Cleaning
+# Cleaning {toc}
## Pre-Cleaning Procedures {toc}
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### Where efflorescence is heavy or persistent, the source of water migration shall be identified and corrected, because cleaning the face without stopping the water source will result in recurrence.
−# Tolerances
+# Tolerances {toc}
## Dimensional Tolerances — Individual Units {toc}
…69 unchanged lines
## The warranty for areas accepted at reduced f'm is limited to workmanship and installation quality and does not independently warrant structural performance, which is an engineering determination made by the Engineer of Record. {note}