Design Details:
MULTI-WYTHE CAVITY WALL SYSTEM
Masonry Cavity Wall System
Lean Green Thermal Machine!
- LEAN: Tall, slim, strong and handsome with limitless design choices
- GREEN: Locally made and installed, minimal carbon foot print
- THERMAL: Low thermal transfer to achieve significant energy savings
- MACHINE: Sustainable passive cavity drainage system, structurally suited for low and high rise performance
Details & Isometric Drawings:
CMU Backup w/ Brick Veneer
Click here for a full set of MIM’s details
SINGLE-WYTHE GENERIC WALL DESIGN
Single Wythe Reinforced Walls
![]() 8″ CMU Exterior (UPDATED) |
![]() 12″ CMU Exterior (UPDATED) |
![]() Generic CMU Single-Wythe Specification |
BlockFlash® SYSTEM
BlockFlash® is an embeddable flashing pan for exterior single wythe CMU wall systems. It collects moisture that infiltrates the wall and flows down the vertical cores and diverts it to the exterior. BlockFlash® is a single wythe CMU flashing system that is useful at all flashing/weep hole locations including base of wall, above door and window openings, above bond beams, in parapet walls, basements and any other locations where flashing is necessary.
Available in:
- 6″ CMU
- 8″ CMU
- 10″ CMU
- 12″ CMU
Product Data Sheet
SDS
LEED
BlockFlash Warranty
Purchase Online
NCMA TEK-19-2B
Installation Instructions
Single Wythe Details
RESIDENTIAL MASONRY
“Guide to Inspecting Residential Brick Veneer” –
Version 2
![]() English Version |
![]() Spanish Version |
Builder Notes (Brick Industry Association)
Advanced Flashing – Stepped Flashing, Bay Windows, and Arches.
![]() Builder Note |
BRICK VENEER/METAL STUD CAVITY WALL DETAILS
Cavity Wall Details
Complete Set of Isometric Drawings & Details Now Available for Metal Stud Application!
Details & Isometric Drawings:
Brick Veneer/Metal Stud Details
S1.1 Brick Veneer/Metal Stud Base Detail (Exposed Foundation w/AVB)
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S2.1 Brick Veneer/Metal Stud Base Detail (Brick Below Grade w/AVB)
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S3.1 Brick Veneer/Metal Stud (Natural Stone/Precast Concrete) Sill Detail
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S4.1 Brick Veneer/Metal Stud (Brick) Sill Detail
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S5.1 Brick Veneer/Metal Stud Window Head Detail
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S6.1a Brick (Natural Stone/Precast Coping) Parapet Detail
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S6.1b Brick Veneer/Metal Stud (Metal Coping) Parapet Detail
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S7.1 Brick Veneer/Metal Stud High Wall at Low Roof
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S8.1 Brick Veneer/Metal Stud Window Jamb Detail
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S8.2 Brick Veneer/Metal Stud Door
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Technical Data:
REBAR LAP SPLICING

Lap Splice Lengths for Masonry Walls
LOCATING CMU CONTROL JOINTS (CJ’s)
Approximate spacing of Control Joints (CJ’s) for reinforced CMU
Using the Empirical Method in NCMA TEK 10-2D, Table 1 calls for a length to height ratio of 1.5 not to exceed 25ft. This assumes you have wire every 16” o.c. The engineering method in NCMA TEK 10-3 has different ratios but still does not exceed 20 or 25 ft.
– Kelly L.K. Walker, Architectural Services Director, Masonry Institute of Michigan, Inc.
Supporting Documents:
![]() NCMA TEK 10-2D – Control Joints For Concrete Masonry Walls – Empirical Method |
![]() NCMA TEK 10-3 – Control Joints For Concrete Masonry Walls – Alternative Engineered Method |
LOCATING BRICK EXPANSION JOINTS (EJ’s)
What are the approximate spacing for Expansion Joints (EJ’s) for a typical brick veneer application? Please read the following supporting documents.
Supporting Documents:
![]() BIA Tech Note 18A – Accommodating Expansion of Brickwork |
![]() Brick Expansion Joints and Wall Openings – J. Gregg Borchelt, PE |
CMU WIRE REINFORCING
What is the best type of wire reinforcement for use in Single-Wythe CMU or Multi-Wythe CMU Cavity Wall Systems?
Answer:
Contrary to popular belief, wire reinforcement does not contribute to structural stability in standard reinforced CMU walls. In fact, the primary purpose of wire reinforcement in modern masonry wall systems is simply to help resist CMU shrinkage cracking. Typically, vertical and bond beam rebar reinforcement serves to resist wind loading.
Ladder wire with cross rods spaced 16 inches on center allows code required centering of rebar, freer flow of grout and promotes full embedment in mortar at every intersection where side and cross rods meet on the inner and outer CMU face-shell, resisting wall shrinkage.
Truss wire is not recommended for use in reinforced CMU. Diagonal cross rods make it impossible to meet grouting standards referenced in IBC and sub-referenced in ACI Building Code Requirements for Masonry Structures.
Surrounding heavy duty 3/16 inch diameter wire with mortar when placed in 3/8 inch bed joints is difficult to say the least. It can actually be detrimental. This is especially evident when considering allowed tolerances for masonry units and joint sizes. Mortar better surrounds wire when utilizing 9 gauge flush-welded side and cross rods, increasing resistance to shrinkage cracking.
Field-formed corners and mesh ties at intersections offer greater performance, economy and safety. Meet code and performance requirements with standard mill galvanized finish for interior walls not exposed to moisture and hot dip galvanized for exterior walls and interior walls exposed to high moisture or humidity.
In the case of CMU wire reinforcement there is truth to the old adage “Less is More”.
Supporting Documents:
![]() NCMA TEK 12-2B – Joint Reinforcement for Masonry Structures |
![]() NCMA TEK 10-3 – Control Joints for Concrete Masonry Walls |
![]() ![]() |
![]() Selecting the right reinforcement for the job – Mario J. Catani |
– Masonry Institute of Michigan’s ‘Frequently Asked Questions’
COLD AND HOT WEATHER CONSTRUCTION
Available Documents:
MASONRY WALL BRACING STANDARDS
INTERNAL WALL BRACING

- 8″ CMU Reinforced
- 12″ CMU Reinforced
- 8″ & 12″ CMU Unreinforced – Allowable Wall Heights
- 8″ & 12″ CMU Unreinforced – Allowable Horizontal Wall Lengths
- Practical Design of Temporary Masonry Wall Bracing Handout
For more information, please contact:
Todd Dailey, PE
Dailey Engineering, Inc.
T: 517-467-9000
[email protected]
www.daileyengineeringinc.com
MICHIGAN WALL BRACING STANDARDS
MIOSHA
Available Documents:
![]() Masonry Institute of MI – Masonry Wall Bracing |
![]() State of Michigan Wall Bracing Standards |
Frequently Asked Questions:
-
How do you calculate correct rebar lap splicing to meet code?
-
What is the approximate spacing of Control Joints (CJ’s) for reinforced CMU?
-
What is the approximate spacing for Expansion Joints (EJ’s) for a typical brick veneer application?
-
What is the best type of wire reinforcement for use in Single-Wythe CMU or Multi-Wythe CMU Cavity Wall Systems?
-
Is wire reinforcement with 3/16 inch diameter side rods or 3/16 inch diameter side and cross rods better than standard 9 gauge side and cross rods?
- Masonry Institute of Michigan’s ‘Frequently Asked Questions’ page
REBAR LAP SPLICING
Lap Splice Lengths for Masonry Walls
Question:
How do you calculate correct rebar lap splicing to meet code?
Answer:
The IBC 2006 adopted MSJC 2005 by reference; however they decided to keep the previous lap lengths of 48 bar diameters. …that engineers may have the option of using MSJC 2005 for their design lap lengths. Depending on the f’m the lap lengths can be shorter particularly in the smaller bar sizes. …Footnotes (1) & (2) represent comments in the IBC code. (1) instructs the engineer on additional lap requirements in areas of high stress, (2) addresses the requirements for epoxy coated rebar. Footnote (3) assumes the bars are spaced at least 8” on center if the bars are closer the table will need to be adjusted. All bars are centered in the wall, if the bars are designed off center the table will need to be adjusted. The f’m is a variable that may be changed to meet your project requirements. The IBC 2009 has adopted MSJC 2008 including the lap lengths. These laps match the MSJC 2005 requirements so the MSJC laps should be what we see in the future.
Below is a lap splice spreadsheet, provided by Kelly Walker of the Masonry Institute of Michigan, which has been updated for IBC 2006 as adopted in MBC 2006. Also below, are the MSJC 2005 laps.
– Kyle Lochonic
LOCATING CMU CONTROL JOINTS (CJ’s)
Question:
What is the approximate spacing of Control Joints (CJ’s) for reinforced CMU?
Answer:
Using the Empirical Method in NCMA TEK 10-2D, Table 1 calls for a length to height ratio of 1.5 not to exceed 25ft. This assumes you have wire every 16” o.c. The engineering method in NCMA TEK 10-3 has different ratios but still does not exceed 20 or 25 ft.
– Kelly L.K. Walker, Architectural Services Director, Masonry Institute of Michigan, Inc.
Supporting Documents:
![]() NCMA TEK 10-2D – Control Joints For Concrete Masonry Walls – Empirical Method |
![]() NCMA TEK 10-3 – Control Joints For Concrete Masonry Walls – Alternative Engineered Method |
LOCATING BRICK EXPANSION JOINTS (EJ’s)
Question:
What is the approximate spacing for Expansion Joints (EJ’s) for a typical brick veneer application?
Answer:
Please see the supporting documents below.
Supporting Documents:
![]() BIA Tech Note 18A – Accommodating Expansion of Brickwork |
![]() Brick Expansion Joints and Wall Openings – J. Gregg Borchelt, PE |
CMU WIRE REINFORCING
Question:
What is the best type of wire reinforcement for use in Single-Wythe CMU or Multi-Wythe CMU Cavity Wall Systems?
Answer:
Contrary to popular belief, wire reinforcement does not contribute to structural stability in standard reinforced CMU walls. In fact, the primary purpose of wire reinforcement in modern masonry wall systems is simply to help resist CMU shrinkage cracking. Typically, vertical and bond beam rebar reinforcement serves to resist wind loading.
Ladder wire with cross rods spaced 16 inches on center allows code required centering of rebar, freer flow of grout and promotes full embedment in mortar at every intersection where side and cross rods meet on the inner and outer CMU face-shell, resisting wall shrinkage.
Truss wire is not recommended for use in reinforced CMU. Diagonal cross rods make it impossible to meet grouting standards referenced in IBC and sub-referenced in ACI Building Code Requirements for Masonry Structures.
Surrounding heavy duty 3/16 inch diameter wire with mortar when placed in 3/8 inch bed joints is difficult to say the least. It can actually be detrimental. This is especially evident when considering allowed tolerances for masonry units and joint sizes. Mortar better surrounds wire when utilizing 9 gauge flush-welded side and cross rods, increasing resistance to shrinkage cracking.
Field-formed corners and mesh ties at intersections offer greater performance, economy and safety. Meet code and performance requirements with standard mill galvanized finish for interior walls not exposed to moisture and hot dip galvanized for exterior walls and interior walls exposed to high moisture or humidity.
In the case of CMU wire reinforcement there is truth to the old adage “Less is More”.
Supporting Documents:
![]() NCMA TEK 12-2B – Joint Reinforcement for Masonry Structures |
![]() NCMA TEK 10-3 – Control Joints for Concrete Masonry Walls |
|
![]() |
![]() Selecting the right reinforcement for the job – Mario J. Catani |
Question:
Is wire reinforcement with 3/16 inch diameter side rods or 3/16 inch diameter side and cross rods better than standard 9 gauge side and cross rods?
Answer:
No, for the most part it is just the opposite. The primary purpose for wire in today’s reinforced walls is to reduce CMU wall shrinkage. It is very difficult to surround 3/16 inch diameter wire with mortar when placed in 3/8 inch bed joints. This is especially evident when considering allowed tolerances for masonry units and joint sizes. Mortar better surrounds wire when utilizing 9 gauge flush welded side and cross rods, increasing resistance to shrinkage cracking. It is no surprise demand for truss wire has fallen significantly in the last decade. The market simply demands higher performance 9 gauge 16 inch core-clear ladder!
Supporting Documents:
![]() Less Is More |
![]() TECH Talk – Daniel S. Zechmeister, PE |
![]() Selecting the right reinforcement for the job – Mario J. Catani |
Industry Promotion:
COST GUIDE
Masonry Wall Cost Guide
The 2008 Masonry Wall Cost Guide is intended to provide users with an in-place wall square footage cost for 145 wall assemblies for six cities in Michigan: Ann Arbor, Detroit, Flint, Grand Rapids, Lansing and Saginaw.
The 870 listed costs are provided as an aid to assist decision-makers in utilizing masonry economically.The figures represent total masonry cost including labor, material, overhead and profit. All masonry wall costs were based on a straight run wall with no openings. The cost will be greater when considering openings, corners, site conditions, material handling conditions and weather. Wall heights vary and were based on applicable design methodologies as noted.
BIA BRICK ORDINANCES
Benefit Community
University of Michigan Masonry Ordinance Research
The 2008 Masonry Wall Cost Guide is intended to provide users with an in-place wall square footage cost for 145 wall assemblies for six cities in Michigan: Ann Arbor, Detroit, Flint, Grand Rapids, Lansing and Saginaw.
The 870 listed costs are provided as an aid to assist decision-makers in utilizing masonry economically.The figures represent total masonry cost including labor, material, overhead and profit. All masonry wall costs were based on a straight run wall with no openings. The cost will be greater when considering openings, corners, site conditions, material handling conditions and weather. Wall heights vary and were based on applicable design methodologies as noted.
![]() View U of M Study |
Thermal Bridging System
Modern Steel Construction
The following article is written by James A. D’Aloisio, P.E., SECB, LEED AP and is published in Modern Steel Construction:
Attending to thermal bridging can make a big improvement in the building envelope.
![]() Steel Framing & Building Envelopes |
![]() Fero Fast Bracket |
MASONRY INDUSTRY ARTICLES
The Story Pole
Following are articles written by the MASONPRO staff, published in MIM’s publication The Story Pole:
![]() Backed Up By Design |
![]() Techniques to Improve Productivity & Wall Performance |
![]() Improved Technique for Flashing & Anchoring Stone |
![]() Anchors to Weeps |
![]() Sequencing Exterior Masonry Systems |
Masonry Magazine
![]() Less Is More |