Wind Causes Wall to Collapse Killing Iowa Construction Worker
Blairsburg, Iowa - This is Hamilton County in, Iowa where a 57-year-old man died after a concrete block wall collapsed. Apparently there is a school addition being constructed at the Northeast Hamilton Elementary School. The wall was 18 feet tall and reported to be at least 12 feet wide.
Was wind the cause; or was it improper bracing? We know about wind. Wind across a construction site isn't something to be unexpected. Saying it's a big gust isn't good enough. Construction sites where walls are being erected require proper bracing and knowledge of the wind conditions including the direction and speed that can cause accidents like this to occur. I've worked on construction site where walls were being erected and never felt comfortable working on the lee side.
- Lee side - The side of a ship sheltered from the wind (cf. weather side).
- Lee shore - A shore downwind of a ship. A ship which cannot sail well to windward risks being blown onto a lee shore and grounded.
- Leeway - The amount that a ship is blown leeward by the wind. See also weatherly.
- Leeward (pronounced /ˈluːərd/ in nautical use) - In the direction that the wind is blowing towards.
There are standards for bracing tall masonry walls. Following this link to the Michigan Occupational Safety and Health Administration web site outlines the requirements for safely working around tall wall as its being constructed on the job site. The requirements include someone having knowledge of engineering principles, proper bracing, warning signage and creating a restricted zone.
If there was a safety zone that the worker breached you first thought may be that his fault will keep him from recovering, but that's not true regarding workers' compensation benefits to his widow or dependents. With regard to a claim being made against other companies on the construction site it could or may not be preclude recovery. Here is a sampling of what you can read on the Michigan OSHA site.
Engineering Guidelines for Bracing Tall Masonry Walls:
The Mason Contractors Association of America (MCAA) established a council to develop a wall bracing standard. The Council published the Standard Practice for Bracing Masonry Walls Under Construction in 1999 and it was revised in 2001 by MCAA. In 2003 the Masonry Wallbracing Design Handbook was also published by MCAA. The Handbook displays over 700 different wall bracing configurations based on the Standard Practice for Bracing Masonry Walls Under Construction. The Handbook serves to assist mason contractors in identifying brace locations for typical applications. The sponsors recognize that not all site conditions can be taken into account in the Handbook. After all, each jobsite is unique. A registered professional engineer should be consulted for situations not addressed in the Handbook.
Responsibilities During Construction of Masonry Walls
- Designate a qualified/responsible person to be present during masonry construction.
- Ensure proper design and installation of bracing.
- Monitor wind speed.
- Monitor, maintain, inspect and ensure wall bracing integrity.
- Post "Danger" signs on all unsupported masonry walls.
- Delineate the collapse area/restricted zone. Evacuate workers when appropriate.
- Communicate with the Controlling Contractor regarding wind speeds, evacuation conditions, wall bracing design used on the project, and any hazardous conditions that may compromise worker safety.
- Know the collapse area/restricted zone requirements.
- Know the wall bracing design used on the project.
- Have the authority to evacuate all workers from the collapse area/restricted zone when appropriate.
- Monitor, maintain, inspect and ensure wall bracing integrity when the Mason Contractor is not on-site.
- Monitor wind speed when the Mason Contractor is not on-site.
- Communicate any hazardous condition associated with wall bracing that may compromise worker safety with masonry and sub-contractor employees.
Sub-Contractor Employers and Employees:
- Train employees in the recognition and avoidance of hazards associated with masonry wall bracing, collapse area/restricted zones, and conditions requiring evacuation.
- Coordinate with the Mason and/or Controlling Contractor when altering or removing any component of the wall bracing system.
Collapse Area / Restricted Zone:
The area on each side of a wall that is subject to the effects of a wall collapse is known as the collapse area or restricted zone. This area is measured at a horizontal distance equal to the height of the constructed wall plus 4 feet, measured at right angles to the wall and continuing for the length of the constructed wall. The area shall be clearly identified by acceptable methods. Proper signage as required in Part 2 - Masonry Wall Bracing shall be placed upon all unsupported walls. Part 2 also requires evacuation of the collapse area when wind speed exceeds 35 MPH.
The Standard Practice for Bracing Masonry Walls Under Construction has two separate requirements for bracing tall walls.
- For walls in the initial period (the period of time limited to one working day, during which the masonry is installed), the collapse area/restricted zone shall be evacuated when wind speed exceeds 20 MPH.
- For walls in the intermediate period (the period of time following the initial period until the wall is connected to the final lateral stability supports), the collapse area/restricted zone shall be evacuated when the wind speed exceeds 35 MPH.
Other resources include Masonry Magazine, The Voice of the Masonry Industry. In Wall Bracing 101 you can see the numerous braces protecting the construction workers. The opening quote seems eerily instructive in this Iowa fatality.
Wall Bracing 101, by Rashod Johnson, Director of Engineering, MCAA
"Bracing masonry walls during construction is often neglected by mason contractors, sometimes with catastrophic results. Even in those cases where some nominal bracing is provided, it is often the case that they are inadequate and can overstress and fail under lateral loads. One of the reasons for this is that mason contractors often lack the in-house engineering expertise to properly evaluate the conditions necessary to design masonry bracings. Proper bracing design entails a number of factors, e.g. strength and age of masonry, mortar and grout, location and magnitude of reinforcement, openings, etc. Before the MCAA began its effort in 1997, there were no uniform structural design guidelines for contractors and engineers to follow while designing the bracing. The formation of the Council for Masonry Wall Bracing was a step undertaken to fill this gap, by providing specification and design parameters for structural bracing. The Standard Practice for Bracing Masonry Walls and the Masonry Wall Bracing Handbook are excellent tools that provide guidance to the contractor to adequately brace masonry walls."
Mohammad Ayub, PE
Director, Office of Engineering
Directorate of Construction, OSHA
There are numerous types of available bracing that save lives. Short cuts create unsuspected hazards.
In worker's compensation claims such as a dependents claim for death benefits involving construction workers visit with an attorney for no reason other than to understand what happens with your benefits should you sometime in the future remarry. Of course widows and widowers aren't thinking of remarriage right after a fatal accident but fully appreciating your rights to life-time workers' compensation benefits is good estate planning for the living dependents.
Be smart by being informed.