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DECK REPLACEMENT SAFE WORK PRACTICES
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Case Study #1 Laborer Killed in Fall Through Roof
A 40-year-old laborer/helper died when he fell through an opening in a warehouse roof. He fell approximately 27 feet to the floor below. The employee was demolishing the roof of the warehouse portion of a commercial building. Work was done at night because the coal tar on the roof would release hazardous gases if disturbed in the heat of the day. The site had adequate halogen lighting. None of the workers on the job were using fall protection. After the roofing material was removed, 4X8 sheets of plywood were exposed. Any damaged sheets needed to be replaced. The helper’s job was to follow the workers who were replacing the plywood, and to pick up the damaged sheets of plywood they had removed. He disposed of them in a chute. On this evening, one worker had removed a sheet of damaged plywood, but had run out of nails to attach the replacement sheet. He walked away to get more nails. The opening where the damaged plywood had been was left unguarded. The crew was not informed that it was temporarily unguarded. The opening was covered by silver-colored insulation inside the roof. The helper came along, picked up the damaged plywood, and headed for the chute. He stepped into the opening, ripped through the insulation, and fell. Review the key facts with the class participants: 1. 40 year old employee fell 27 feet through the roof. 2. Employee was removing the existing roof. 3. No fall protection 4. Damaged sheets of plywood were exposed and to be replaced. 5. Employees ran out of nails and could not attach a sheet of plywood. 6. An employee stepped into an open hole while removing plywood. Ask the class if this was preventable, and what could have been done to prevent it.
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Case Study #2 Journeyman Roofer Dies From 25-Foot-Fall Through Structural Decking A 31-year-old journeyman roofer fell 25-feet through a section of a flat pitch roof. At the time of the incident the workers were in the process of tearing off and replacing roofing material on a flat pitch roof. The workers also were identifying bad and weakened sections of structural decking by visually identifying them from inside the building, taking measurements as their position and transferring those measurements to the roof and marking the appropriate sections for replacement. The bad sections of roof were marked with spray paint and the workers were instructed not to walk on the marked sections. The replacement sections are two feet wide and up to eight feet long. They were cut to to fit when replaced. On the day of the incident the workers were continuing tearing off the roofing material and replacing the identified bad decking. At approximately 11:00 a.m. the victim and another worker were walking on the roof and were near an identified bad section of decking when the worker fell through the decking to a concrete floor below. According to the employer there were no indications that the section of decking the worker fell through was weak or bad. The job foreman was first to the victim and requested a coworker to call 911 for emergency assistance. Emergency crews arrived and transported the victim to a local trauma center where he was treated for severe head trauma. The victims condition deteriorated and he was pronounced deceased the following day. Review with the class what is similar between this case study and the first one. Some answers should be: 1. Employees was tearing off the existing roof. 2. Lack of fall protection. 3. Poor pre-job planning
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Duty To Have Fall Protection
The employer shall determine if the walking/working surface on which its employees are to work have the strength and structural integrity to support employees safely. Employees shall be allowed to work on those surfaces only when the surface have the requisite strength and structural integrity. In the event the a deck has damage or is potentially not strong enough to hold employees, equipment, and material fall arrest procedures or a catch platform/ net immediately below the working surface should be implemented.
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Subpart R vs Subpart M (b)(4) – Holes: Each employee on walking/working surfaces shall be protected from falling through holes (including skylights) more than six (6) feet above lower levels, by personal fall arrest systems, safety net systems, covers, or guardrail system erected around such holes. (a)(1) –General Requirements: Except as provided in paragraph (a)(3) of this section, each employee engaged in steel erection activity who is on a walking/working surface with an unprotected side or edge more than 15 feet above a lower level shall be protected from fall hazards by guardrail systems, safety net systems, personal fall arrest systems, positioning device systems, or fall restraint system Due to the deck being replaced,
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Subpart R vs Subpart M Question (1)(a): Scenario: A commercial roofing contractor is engaged in a re-roofing job. In the course of removing the weatherproofing material, the contractor discovers that some of the metal roof decking has deteriorated, and that a 6' X 6' section has to be replaced. Is this replacement work covered under Part 1926 Subpart R? Answer Under § (a), Subpart R is not limited to new construction - it also applies to steel erection activities in alteration and repair work. Section (b)(1) contains a list of activities that are covered by Subpart R, including "installing metal decking." Since § (a) states that steel erection activities done during repair are covered by Subpart R, the reverse of the decking installation process - removal - is also covered under § (b)(1).
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Subpart R vs Subpart M Question (1)(c): Assume that the roof is between 15 feet and 30 feet high. Can the employer use a Controlled Decking Zone as a substitute for conventional fall protection for the employees engaged in removing the bad decking? Answer No. Section (c) states that: "a controlled decking zone may be established in that area of the structure over 15 and up to 30 feet above a lower level where metal decking is initially being installed and forms the leading edge of a work area..." [Emphasis added] The controlled decking zone option was designed specifically for the initial installation of metal decking. The removal of deteriorated decking involves hazards that are not addressed in the controlled decking zone provision (for example, the fall hazards encountered when cutting decking and/or removing welds or fasteners). Therefore, the controlled decking zone exception does not apply to this deck removal work; conventional fall protection must be used.
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Types of Roof Decking Corrugated Metal Wood Gypsum Tectum
Explain to employees the different types of building that would have each of these decks. Metal is typically the most common type of deck found on the majority of flat buildings. Wood Decking is common in houses. Tongue and groove was once common in older municipal buildings and factories, but is rare in newer buildings. Tectum and Gypsum are commonly found in municipal building such as schools. Different decks are more common in different sections of the country.
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Decking Deterioration
Corrugated Metal Rust Electrolysis Wood Dry Rot Saturation Crushed / Split Gypsum Moisture Spalling Cracked / Split Dry Tectum Most of the damage that occurs to decking is due to water damage. Other ways damage can occur to decking is from weather, material being dropped on the roof, or a chemical reaction within the building.
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Hazard Identification
Interior Evaluations Water stains Rust Sagging Cracked/Peeling Paint Humidity Owner’s Representative Age of Building Structural Design Constant Leaks Interior evaluations should be conducted prior to rooftop evaluations. T
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Hazard Identification
Interior Evaluations Water stains Rust Sagging Cracked/Peeling Paint Humidity Owner’s Representative Age of Building Structural Design Constant Leaks Owner Rep’s are a good source to get addition information about the building. A leak history can info you to locations where problems may exist.
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Hazard Identification
Exterior Evaluations Ponding Repairs / Patches Sagging Spongy Insulation Inferred Scans Pay close attention to areas with ponded water and where a patch is present. Patches should lead you to believe that existing damage is present to the roof and potentially to the deck. An infrared scan can show where moisture is present in the insulation. An infrared scan is best complete a dawn on a sunny day. By doing it later on a sunny day, the water potentially in the roof has the ability to warm all day. Moisture will hold the temperature longer compared to dry insulation.
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Hazard Identification
Exterior Evaluations Ponding Repairs / Patches Sagging Spongy Insulation Inferred Scans It is always preferred to complete the interior evaluations first. By completing the interior evaluation first, you can better determine where it is safe to walk for the roof top inspection.
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Employees identified wet gypsum decking material
Employees were able to see that the roof was deteriorated from the top. It is always preferred to first conduct an under deck inspection. Employees identified wet gypsum decking material
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100% tie off utilized while working at edge and around roof opening
Please not it is always preferred to tie-off overhead. This will help limit the fall as much as possible. Employees should also consider proper clearance distances to ensure they will not hit the next lower level. 100% tie off utilized while working at edge and around roof opening
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100% tie off utilized while working at edge and around roof opening
This crew was utilizing a fall restraint system. Employees were tied off in a manner that would allow them to reach the edge of the opening, but not step in to it. 100% tie off utilized while working at edge and around roof opening
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Decking Go-Over Sistering Sheets Stainless Steel Plates
Depends on flutes Primarily B-decking Stainless Steel Plates 2’ x 2’ 3’ x 3’ Etc. By placing a new sheet of deck over the old, you can strengthen the system, and have employees less exposed to a fall hazard.
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Eliminate the Fall – Interior Scaffolding
Interior scaffolding can be used as a catch platform and should be set as close to the working surface as possible, but never more than six feet in depth.
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Eliminate the Fall – Netting Systems
Employees are using guardrails to enclose the work area and netting as the fall protection into the opening.
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Fall Protection Options
Corrugated Metal / Wood Roof Anchors Fall Protection Carts Horizontal Lifelines Gypsum / Tectum Toggle bolt 2”x 10” – attach roof anchor Fasten roof anchor to steel support beams Feed choker cable through deck and around steel support beams Uses: Removing or installing coping Tear-off and installation of leading edge Removal and replacement of in-field roof deck Installing or dismantling edge guardrail systems Working around roof openings Removing or installing covers or skylights Snow removal Different fall protection carts have different setup requirements. You should always refer to the owner’s manual prior to setting up a fall protection cart.
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Safe Work Practices Hazard Identification Sequence scope of work
Flag off suspicious section of decking Transfer marks / measurements from interior inspection Sequence scope of work Maintaining a solid working surface Have replacement sheets pre-cut / ready to be in installed immediately In addition to flagging of the bad areas, spray paint can also be used to mark them on the roof, but this would not constitute fall protection. Flagging off the bed deck can only be used as a fall protection method when employees are not going in an are with bad decking. Plywood laid out to provide solid working surface.
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Safe Work Practices Communicate with primary contact
Conduct electrical inspection – Lock out power supply Have dedicated inside rover to monitor work location Flag off areas below deck replacement In the event that electrical wire are set into the flutes either on the underside of roof side of the deck, a lock out of the electrical source should be completed.
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Summary Conduct a comprehensive evaluation of the roof deck to ensure it will support the men and materials. Perform the deck replacement with a small crew before major tear off when feasible. Develop a fall protection plan: Is tie-off enough or will the area require netting? Protect areas on the roof and inside the building from unauthorized access. Never leave an open section of decking.
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