In 2010,MIOSHAConstructionSafety Standard Part 2Masonry Wall Bracing wasamended by the Secretary of State of Michigan.This amendment culminates years of recommendations by the Masonry Institute of Michigan for changes to the standard forclarification and to increase workplace safety,due to outdated information, omissions andinconsistencies in of the 1989 standard.Several revisions are critical for safety of allindividuals present on a construction job site.

Nationally, the US Department of Labor,Occupational Safety & Health Administration(OSHA) regulation 9 CFR 1926.706(b) requiresthat a limited access zone be established priorto construction of a masonry wall and thatwalls over 8' be braced. The regulation doesnot indicate what the bracing should entail tobe appropriate or adequate for the job. At thestate level, Michigan’s Department of Energy,Labor & Economic Growth agency, MIOSHA,took the national regulation a step furtherwith this amendment, establishing morethorough and enforceable rules.

The scope of Part 2 Masonry Wall Bracing isthe bracing of unsupported masonry wallsexposed to wind during construction. Theprimary purpose is to protect workers fromany under construction masonry wall blowdown due to wind. Within this scope, itprovides for wall bracing design, a restrictedzone, maximum heights of braced and unbraced

walls, wind speedrequirements andtraining. It is crucial forall persons present on a construction site to betrained to recognize masonry bracingrestricted zoning and the appropriatebehaviors expected in and around the zone.

Acknowledging AdvancementsThe standard provides a wall bracing designmade from 2x10 scaffold grade lumber commonin the masonry industry. This type of bracing iseffective for shorter masonry walls historicallyfound. Changes in design and engineering ofpresent day masonry walls have led to taller,thinner reinforced masonry walls. The standardnow references The Standard Practice for BracingMasonry Walls Under Construction chapters 5 &6 and the Masonry Wall Bracing Design Handbook.These important documents address these tallerthinner walls more prevalent in modern masonry.

Mason Contractors Association of America’s(MCAA) The Standard Practice for BracingMasonry Walls Under Construction had beenconsidered a best practice, but was not agovernment standard. Now that is has beenadopted as such by Michigan, others shouldlook to this as an industry standard and a jobsite expectation. Partial rules are excerpted

here with commentary;for a complete version of the

standard see michigan.gov/documents/CIS_WSH_ part_2_47091_7.pdf

Clear Definitions Improve AccountabilityThe competent person – one who is trained,experienced and capable of identifying existingor potential hazards and who has the authorityto take prompt corrective action to eliminatehazards – is a key provision of many MIOSHAstandards. This is the person doing the actualwork in the field related to the standard.

Initial and Intermediate periods are similar torequirements found in The Standard Practicefor Bracing Masonry Walls Under Construction.The initial period, defined as the period oftime, not to exceed 24 hours, during which themasonry wall is being laid above its base or the highest line of bracing and, at the end ofwhich, required bracing installed, representsthe period when the mortar has not developedsufficient strength to resist lateral wind loads.The intermediate period represents the periodof time greater than 24 hours after the masonryhas been laid.

The restricted zone represents the area wheremasonry wall blow down from wind couldoccur. It is measured by a horizontal distanceequal to the height of the constructed wallplus a minimum of 4', measured at right anglesto the wall, and continuing for the length ofthe wall plus a minimum of 4' beyond the endsof the wall. The restricted zone is limited totrained personnel only and is defined by signage.

44 2011 Vol 6 No 1 MASONRY EDG E / the storypole Masonry Technology | Innovation

MASONRY WALL BRACINGLife safety under windy conditions paramount to updated standard

PART 2 By Kyle Lochonic

Illustrations courtesy of MIOSHA

This article originally appeared in MasonryEdge/theStoryPole Vol 6 No 1.

Key Provisions Affect Workplace SafetyR 408.40204 Responsibilities; restricted zone, wall bracing system and signage | Rule 204This rule defines the prior planning requirements; establishmentand maintenance of the restricted zone, including regular moni tor ing of wind speed; and requirements for employers,masonry or otherwise, having workers in the restricted zone.Prior plan ning assures that a thoughtful process is already inplace when masonry walls are being constructed. This shouldalso help to establish a sequence of work flow designed to limitexposure.

R 408.40205 Training requirements | Rule 205The training requirements are new. They establish require mentsfor the mason contractor’s employees in establishing therestricted zone, installing the wall bracing system, evacuatingthe restricted zone when required by windy conditions,evaluating hazards and maintaining the restricted zone and wallbracing system. They also establish requirements for employeesworking in the restricted zone. These employees typically workfor other subcontractors. Training requirements are arguablythe most important element of the amendment. Most injuriesand deaths related to wall blow down due to wind are toworkers in trades other than masonry. Non-masonry workersworking on the leeward side of a masonry wall exposed to windmay be more oblivious to the danger than masonry workers.The requirement for training documentation is consistent withother MIOSHA safety standards. It must be documented inwriting. A written certification record containing the names ofthose trained, dates of training, signature of trainer and/oremployer must be maintained and accessible throughout thework shift.

R 408.40206 Restricted zone requirements | R 408.40207 Signing requirements | Rule 206, 207The restricted zone replaces the collapse area of the previousstandard and its definition is consistent with The StandardPractice for Bracing Masonry Walls Under Construction. Inaddition, a requirement for the restricted zone now includes 4'beyond each end. This allows some leeway if the wall blowsdown from one end to the other and the debris is not perfectlyperpendi cular. Signage is now standardized at the perimeterand on the wall. The perimeter of the restricted zone is definedby signs at 50' oc. It was felt that items such as caution tape orrope delineating the perimeter would interfere with theoperation of equipment such as forklifts used in construction ofthe wall and be rendered ineffective.

Additional information is including for handling signage acrossroadways or other adjacent areas, alternate protectivemethods and restricted zones for multi-story structures.

R 408.40208 Wind speed; determination by competent person | Rule 208Wind speed can no longer be determined by observation only;an anemometer (wind measuring device) must be used withinthe vicinity of the wall under construction. With the availability,

2011 Vol 6 No 1 MASONRY EDG E / the storypole Masonry Technology | Innovation 45

TABLE 1 INITIAL PERIOD (LESS THAN 24 HOURS)

Maximum Unbraced Height of Unreinforced Masonry Above its Base or Highest Line of Bracing for Resisting 20 mph Wind

Nominal Thickness

Unit Weight of Masonry

Light Weight1

(<105 pcf) Medium Weight2

(105 to <125 pcf)Normal Weight3

(≥125 pcf)

Maximum Height Maximum Height Maximum Height

4" 8'-0" 8'-0" 8'-0"

6" 8'-0" 8'-0" 8'-0"

8" 9'-4" 10'-0" 12'-0"

10" 13'-4" 14'-8" 17'- 4"12" 18'-0" 20-0" 24'-0"

TABLE 2 INTERMEDIATE PERIOD (GREATER THAN 24 HOURS)

Maximum Unbraced Height of Unreinforced Masonry Above its Base or Highest Line of Bracing for Resisting 35 mph Wind

Nominal Thickness

Unit Weight of Masonry

Light Weight1

(<105 pcf) Medium Weight2

(105 to <125 pcf)Normal Weight3

(≥125 pcf) Unbonded Masonry4

Maximum Height Maximum Height Maximum Height Maximum Height

4" 8'-0" 8'-0" 8'-0" 8'-0"

6" 8'-0" 8'-0" 8'-0" 8'-0"

8" 8'-0" 8'-0" 8'-0" 8'-0"

10" 8'-0" 8'-0" 8'-8" 8'-0"

12" 9'-4" 10'-0" 10'-8" 8'-0"

TABLE 35

INTERMEDIATE PERIOD (GREATER THAN 24 HOURS)Maximum Unbraced Height of Unreinforced Masonry

Above its Base or Highest Line of Bracing for Resisting 20 mph Wind

Nominal Thickness

Unit Weight of Masonry

Light Weight1

(<105 pcf) Medium Weight2

(105 to <125 pcf)Normal Weight3

(≥125 pcf) Unbonded Masonry4

Maximum Height Maximum Height Maximum Height Maximum Height

4" 8'-0" 8'-0" 8'-0" 8'-0"

6" 9'-4" 10'-0" 10'-8" 8'-0"

8" 14'-8" 15'-4" 16'-8" 9'-4"

10" 18'-8" 20'-0" 22'-0" 13'-4"

12" 23'-4" 25'-4" 28'-0" 18'-0"

accuracy and reasonable cost of portable hand held anemometers, it was felt thisrequirement would eliminate inaccurate guessing at the wind speed. Thedetermination is the responsibility of the designated competent person.

R 408.40209 Initial period requirements | Rule 209 During the initial period the wall is supported by its dead weight only. Bracing thewall would be ineffec tive. For this reason the wind speed is limited to 20 MPH forwork in the restricted zone.

R 408.40210 Intermediate period requirements | Rule 210At the intermediate period, the mortar is developing flexural strength and iscapable of resisting lateral wind loads. Bracing (if required) is installed and therestricted zone is permitted to be occupied for wind speeds up to 35 MPH.

Tables 1 through 3 replace the tables in the previous standard. They includeengineering calculations as required by current codes. They now are based on

1Light Weight Units: 95 pcf2Medium Weight Units: 105 pcf3Normal Weight Units: 125 pcf

4Flashing or Other5Tables 2 & 3 based on Type N masonry cement mortar

CMU only, include three weight classes andmake an allowance for unbonded masonry.The tables are based on Type N masonrycement, a general purpose mortar mix. Higherstrength mortars may increase maximumheights. Consult with a structural engineer forvariations in wall brace design.

R 408.40211 Wall bracing design |Rule 211Wall bracing systems must be designed andcapable of providing stability to the wall for awind speed of 40 mph with erection drawings,plans or calculations and specifications availableat the jobsite.

Wall bracing design includes the standardtriangle wall brace system and provisions forthe use of The Standard Practice for BracingMasonry Walls Under Construction chapters 5 & 6. These chapters provide engineeringrequire ments and material properties fordesign alternate bracing systems such as steel pipe braces.

Masonry Wall Bracing Design Handbookprovides for using vertical reinforcing andgrout as an internal wall brace system.

R 408.40212 Triangle wall bracing system | Rule 212Rule 212 defines the standard triangle wallbrace system fabricated from scaffold planks.The connection to the wall and connection ofthe various mandatory components are defined.It also delineates spacing for various wallthicknesses and establishes a maximum height.

These items represent some of the keycomponents of the revised Part 2 MasonryWall Bracing devised to improve understandingof methods and responsibilities on a job site,but most importantly to decrease life safetyrisk to all persons in a construction zone. Athorough review of the entire standard shouldbe completed before constructing a masonrywall requiring bracing. � � �

46 2011 Vol 6 No 1 MASONRY EDG E / the storypole Masonry Technology | Innovation

Masonry Wall Bracing

KYLE LOCHONIC is a project manager for DavenportMasonry in Holt, MI. He sits on the MIM Masonry Alliancewith MIOSHA and was chair of the MIOSHA Part 2 MasonryWall Bracing Advisory committee. He is standing memberof the MIM Generic Wall Design Committee and a trustee onthe BAC Local 9 Pension and Health and Welfare funds. Asecond generation bricklayer, Lochonic has been employedin the masonry industry for 40 years. 517.699.6199 |klochonic@davenportmasonry.com

Typical Triangle Wall Bracing System