Slide Guards: Myths and Facts
Not a year goes by that I don't hear from a few builders on the subject of slide guards used as fall protection devices on roofs. While most of these residential contractors are predominantly framers and roofers, I occasionally hear from plumbers, electricians and other trades-persons who also make access onto residential roofs. After a brief discussion, it soon becomes clear that they are all working without the facts. In this article I will try to bust the eight myths about slide guards for roof workers.
Myth #1: We Call Those Toe BoardsOne of my first carpentry assignments as an apprentice (apart from constructing a "test" set of saw horses for the foreman) was to build a dozen or so stop-boards to be installed on a roof. Some builders here in the Northeast call them "strong-backs" while one contractor in Colorado named them "cripples" (for obvious reasons). I have even heard them termed "toe boards" in the Northwest, which obviously contradicts that lowest portion of a guardrail system intended to prevent workers feet and debris from accidentally slipping off a work level or scaffold platform. The broad term "toe board" is clearly defined by OSHA in 1926.500(b): "A low protective barrier that will prevent the fall of materials and equipment to lower levels and provide protection from falls for personnel."
ANSI describes a toe board as a component of a guardrail system, as having a nominal 4-inch height and structure capable of resisting 50 pounds of force applied horizontally at mid-length without failure. Therefore, it is unlikely that such an assembly was intended to prevent a rapidly sliding 200-pound roofer from falling off of an 8:12 pitch roof. OSHA's term for this site-constructed precautionary device is a slide guard. But whatever they're named, their purpose is to prevent workers unfortunate enough to slip or trip on the roof deck from continuing to slide down the slope and inevitably drop off the eave to the ground below.
We all know it's not the fall, but the sudden stop at the end that injures or kills the victim who is unprotected by PFAS, guardrails or safety nets. Beware overconfidence. Much like a safety monitor, this temporary, site-constructed system of guards is a less-than-perfect hazard control. It is intended to be used only by a specific set of approved workers during a limited set of work tasks on the roof deck.
Myth #2: Slide Guards Will Provide Fall ProtectionNo they won't. Rather than conforming to the strict criteria of a standard fall prevention technique, slide guards are more properly considered trade-standard precautions. Only under a very limited set of site conditions will the slide guard acts as a dependable method of fall prevention. It cannot be truly categorized as fall protection either, which mitigates the effects of a fall that occurs. It also fails to attain the minimum threshold of an engineering control, as defined by ANSI/OSHA. An engineering control method totally removes the hazard, by either 1) removing the employee from the danger zone or point of initiation; 2) disabling the injurious effects of the hazard; or 3) disarming the trigger that initiates the event. In other words, no matter how hard we try, we cannot be physically harmed by the hazard when managed properly by an engineering control.
A slide guard potentially provides two functions for the roofer: 1) To visually caution the worker accessing the roof that the fall hazards are less than engineering quality; 2) To possibly terminate a sliding victim before dropping off the eave to the grade below. The fact is: Instituting a slide guard system on a roof is neither a standard fall protection nor a fall prevention measure. It is an alternate means of precaution against falls under a specific set of limiting criteria.
Myth #3: Anyone Can Use Slide GuardsThe only mention of the employer's installation and employee's use of slide guards in OSHA's fall protection standard (Subpart M, 1926.500) is in Appendix E, Sample Fall Protection Plan. Here in this non-mandatory guideline, the employer is given several illustrations of compliant, written and site-specific fall protection plans. The Sample Fall Protection Plan for Residential Construction contains several paragraphs on slide guards under its section entitled "Roof Sheathing Operations." The OSHA standards are intended to be understood by the employer as minimal safety regulations. An employer cannot be cited for not complying with any procedure described in a non-mandatory appendix, but should be encouraged to adopt it as a guide to attaining compliance with the entire body of the standard.
Upon consultation with a number of federal and state OSHA compliance safety and health officers concerning slide guards, most agreed that their regulatory enforcement on this issue followed the OSHA compliance directive #STD 03-00-001 (replacing STD 3-0,1A). This new directive was issued in 1996 as the "Interim Fall Protection Compliance Guidelines for Residential Construction." This plain language instruction was deemed by OSHA to enable and assist compliance officers to interpret residential site conditions and work practices in terms of applicable sections of 29 CFR, Part 1926. Initially, it defines four primary groups of residential construction activities:
Group 1: Installation of floor joist, sheathing, roof sheathing, exterior wall erection and setting/bracing roof trusses/rafters
Group 2: Concrete and block foundation walls and related form work
Group 3: Installing drywall, insulation, HVAC and electrical systems, plumbing and carpentry (when performed in attics and on roofs)
Group 4: Roofing work (removal, repair or installation of weatherproofing roofing materials such as shingles, tile and tar paper or underlayment)
This document also describes alternative fall protection plans and procedures the employer shall make available to workers in any of these four groups. All other workers on a residential construction site are regulated and expected to be protected by an OSHA-standard fall protection control method.
Myth #4: I Can Use Slide Guards AnywhereThis STD compliance directive initially calls for several primary site requirements to be met before the criteria for slide guards in Group 4 may be legally implemented. While there is no particular order to these, they should be considered carefully by the employer according to the predominant site conditions.
The roof slope must be 8:12 pitch or less
Eave-to-ground height is 25 feet or less.
Only workers proficiently trained in the alternative method of slide guards should be allowed on the roof (controlled access zone).
Good housekeeping should be practiced. Inspect and remove slip hazards on the roof.
Properly selected, clean footwear required and provided.
Abort criteria established for adverse weather conditions.
Roof holes and damaged decking must be identified and adequately guardrailed or covered
Ladders and scaffolds inspected must be maintained and used according to Subparts L and X.
Roof access to ascend or descend is prohibited within 6 feet of gable-end rake edge (danger zone).
No building supplies and materials stored within 6 feet of rake edge (3 feet on tile/metal)
A controlled access zone secured below the eave and rake edges removing (or guarding) impalement and other impact hazards.
Keeping in mind the OSH Act's General Duty Clause 5(a)(1), it is also incumbent upon the roofing contractor to identify any other applicable roof hazards that may exist or potentially affect the workers who depend on slide guards as an alternative fall protection method.
While this somewhat obscure compliance directive may be randomly interpreted by compliance officers from region to region, there are three distinct and constant criteria for compliance on which it is based. The myth exists that slide guards may be legally installed on any roof regardless of pitch or surface material. The fact is that the directive for alternative protection methods continues to stipulate procedures to be employed depending on the specific slope and material of the roof on which slide guards are to be installed.
1. Any Roofing Material
0-4:12 pitch: Choose between either: safety monitoring system (1926.502) or slide guards (STD 03-00-001)
4-8:12 pitch: Slide guards are required
Over 8:12 pitch: alternative fall protection methods are prohibited
Eave height greater than 25 feet: alternative fall protection methods are prohibited
2. Tile or Metal Material
0-8:12 pitch: Safety monitoring method may be used as a practical alternative to slide guards (difficult to install)
3. Except Tile or Metal Material
4-8:12 pitch: Slide guards are required
It is in this particular area where I have seen the widest range of subjective interpretations by OSHA compliance officers around the country. Often the pitch and height of the roof is not literally measured, but rather estimated by eye during inspection. While a 25-foot eave height is generally meant to indicate a two-story roof, varying foundation exposures and second floor rafter plate heights can throw off any height estimate.
Myth #5: Roof Brackets are also Slide GuardsAnother myth that exists is that roof brackets with scaffold planks may be used for the purpose intended as well as for fall protection. The fact is, while they may resist the forces imposed by a sliding fall victim, the manufacturer of these scaffold components did not intend them to be used for that purpose. The brackets that I own are not even adjustable to 90 degrees. The horizontal scaffold plank is just that-a walking, working, material storage surface. The problem becomes one of physics when used for slide guards. The slide impact, rather than meeting a perpendicular stop surface, may actually create an uplift force on the plank edge and possibly pull the fasteners from the roof deck.
All scaffolds have an assigned manufacturer's maximum rated load. Should a worker make side impact on a roof bracket scaffold that is loaded near its maximum rating, it may not be capable of resisting the combined forces without failure. The truth is that an employer who intends to use roof bracket scaffolding for the purpose of slide guards is in violation of the OSHA compliance directive #STD 03-00-001.
It is also a myth that OSHA's standards mandate that the employer install only manufactured steel slide guards on the roof. They also may be site-built and installed by the employer from 2-inch by 6-inch #2 or better framing lumber (spruce, pine or fir). This is a task that should be assigned to the employer's competent persons. The selection of materials, splitting, checking, cupping, waning, weathering (color) or any other visual defects, while they need not comply with the scaffold grade tensile strength of 1,500 psi fiber stress (i.e., #1 douglas fir), it would just stand to reason that these materials should be of the best quality available.
A heavy-duty scaffold plank which may be uniformly loaded to 75 pounds per square foot (surface area), may not be capable of resisting the amplified impact force from a sliding 250-pound roofer striking mid span with both boots. There are no assembly criteria specified in the regulation, similar to those found in the scaffold standard, but it is reasonable to assume that overbuilding your slide guards is preferable. I use a quality lumber adhesive between two 12-foot members and galvanized screws after first tacking the assembly together. I do not use diagonal-cut 2X for gussets between the perpendicular 2x6 members, as they are too small and prone to splitting. Instead I screw 3-inch by 3-inch galvanized steel angle brackets at 12 inches on center. I pre-drill the deck plate and install the guards with 1/4- by 4-inch galvanized lag bolts with washers to the rafters/truss chords below the deck. This creates a slide guard that, if stored properly, may confidently last several seasons before taking out of service. Their only drawback is their length and weight, which requires two workers to install.
When the roof slope is 6:12 or less, the minimal size of the slide guard materials is 2 inches by 6 inches (nominal). While they do not have to meet the scaffold-grade lumber requirement of 1,500 pounds per square inch for fiber-stress without failure, it is only reasonable that the spruce/pine/fir or better materials should be free from splits, checks, large loose knots, waning or cross-grain cuts. One row of slide guards must be installed within the first three rows of finish roofing material (shingles) or before one course of felt underlayment is applied. No additional rows of slide guards are required at this pitch, unless the contractor determines it is necessary. The nails or screws used to attach the slide guards to the roof shall be of adequate quantity length and diameter to secure the guard to the framing below deck to substantially sustain the force of a sliding worker without failure.
The impact face (5 1/2 inches height) of the guard must be perpendicular to the roof deck plane. 1926.500 Appendix E suggests: "Workers should install the (first row of) slide guards while standing in truss webs and leaning over the sheathing. Additional rows of roof sheathing may be installed by workers positioned on previously installed rows of sheathing. A slide guard can be used to assist workers in retaining their footing during successive sheathing operations; and additional slide guards shall be securely attached to the roof at intervals not to exceed 13 feet as successive rows of sheathing are installed. For roofs with pitches in excess of 9:12, slide guards will be installed at 4-foot intervals."
What is interesting in this OSHA-recommended guideline is that slide guards on a roof over 8:12 pitch are clearly prohibited by the subsequent CPL Directive. When the roof slope is more than 6:12 pitch (up to and including 8:12) the first row of eave slide guards are required as in less than 6:12 roofs. Additional rows are also required up the roof pitch, in intervals not to exceed 8 feet. Each row is installed by workers bracing themselves on the row below. The standard does not require these slide guards to be designed 90 degrees perpendicular to the roof plane. In other words, adjustable roof brackets may be utilized above the eave line. Be advised, however, that roof brackets are horizontal scaffolding (perpendicular to grade) and may not be designed by their manufacturer for the purpose as slide guards.
While it is mandatory that all slide guards installed in the first eave-edge row are continuous end-to-end, sequential slide guards above the eave-edge row do not have to be continuous end-to-end, but evenly spaced to prevent a worker to pass through (usually less than 4 feet apart). Someone qualified to make these site-specific decisions should be designated by the employer to be on the job during design, construction and installation of roof slide guards. OSHA may not require the employer to name the qualified, competent and authorized persons in writing, but in order to encourage employee involvement in the Safety and Health Program, it is recommended that they be named and their duties specified in the document.
Myth #6: I Can Use Them Anytime I WantAs with any OSHA regulation, the employer is always bound by the General Duty Clause and should consider performing a Job Safety Analysis (JSA) whenever considering implementing an alternative fall protection plan. Some of the more obvious decision criteria for limiting roof hazards to be considered before installing slide guards are:
Infeasibility: Whenever, wherever either your work interferes with establishing a standard fall protection system or your fall protection system is compromised by elements of your construction project, this alternate system may be applied by a competent person.
Greater Hazard: Whenever a conventional fall protection/prevention system on your particular site during specific operations has the potential to create another hazard with increased severity or probability than the original fall hazard, then this alternate system may be applied by a competent person.
Inclement weather: A little rain (or dew) on the waxy surface of CDX or OSB roof decking can prove quite dangerous. More obvious is ice and snow. At the first sign of any suspect storm all slide-guard activities should cease immediately. No one should be on a roof whenever lightening is a potential. Remember lightning may commonly occur well ahead of a charged weather front.
High winds. How much wind is too much if you're depending on slide guards? Its really up to the competent person on site. A lower mph threshold might be considered when workers are handling sheet goods with a high wind resistance. It has been reported that more people throw themselves off the roof than are blown off. In other words, they fall more often when the wind gust ceases and the worker has been leaning into the opposing force.
Slippery conditions. Whether created by the elements or by poor housekeeping, the standard is clear: Slippery conditions are prohibited on all roofs at all times. This is considered performance-based regulatory language, and there is no real statutory way to defend yourself if you have not made efforts to keep the roof free of slippery conditions. Good housekeeping is the key.
Difficult to handle materials: If you are utilizing slide guards and handling large or clumsy materials on the roof, it is best to either break the load down into more manageable portions or get some extra hands to handle the job. Otherwise, establish a standard fall protection system.
Multiple employers: Be extremely cautious when more than one employer is assigning work to their employees on your roof deck if all you have are slide guards for protection. Make sure you've adequately identified the controlled access zone and prevent anyone from gaining access to the area without YOUR employer's written authorization and proof that they are adequately trained by their employer.
Multiple Workers: Perhaps the only personnel on the roof are your co-workers, but there are just too many of them to work comfortably. Then the competent person should immediately decide on who should abstain from their tasks until other steps have been completed. What started out being a well designed slide guard for three roofers can quickly become very dangerous trip hazards when there are a dozen workers on the roof.
Myth #7: I Can't be Cited if I Use Slide GuardsA little background may be necessary before I bust this myth. The Interim Fall Protection Guidelines for Residential Construction (STD-03-00-001) were issued in 1999 by OSHA to assist in informing compliance officers in plain language how best to interpret 1926.500 in their Field Inspection Reference Manual (FIRM). It replaced the previous 1995 standard directive (STD 3.1) and was intended to impact any of the 21 state OSHA plans, although many of their officials may mandate its practices. The application of this STD includes any project considered "residential" in nature, wherein the working environment, building materials and construction procedures are similar to those found on single family and town home sites. These projects are generally characterized by wood framing rather than light or heavy gauge steel or concrete. These may also include specific, ancillary portions of commercial or industrial facilities such as foyers, annexes, gift shops, dining areas or outbuildings where the structure clearly resembles a residential style.
Falls from heights greater than 6 feet are the root causes of 33 percent of all construction fatalities. The most predominant point of origin for a falling worker is the roof, followed by scaffolding. While little is statistically known about falls involving slide guards, they are at best considered fall precautions. They are known as "alternate" methods compared to the standard protection methods (guardrails, PFAS and safety nets). As an alternate, they may only be used when all other means prove either infeasible or pose a greater hazard to the user. Adequately slide guarding a roof can raise some confusing compliance issues. As with most regulations, interpretations, variances and citation penalty values may vary greatly from regional offices to regional offices as well as site-to-site.
After the compliance officer has conducted a careful site analysis and employee interviews, the egregious level of any citation is heavily dependant on the compliance officer's discretion. In the matter of slide guarding for Group IV roofers, "good faith" efforts to properly deploy, install and use adequate slide guards are weighed by the inspector. As it is often the case with residential inspections, they may be readily conducted from an "off site" location, such as an adjoining public street, building or common right-of-way. Details of an employer's fall protection plans, methods and materials can be easily discerned by eye (or binoculars). The majority of compliance officers I asked were most concerned with six primary inspection items (depending on the site) to determine the employer's "good faith" status:
Were eave heights and roof pitches accurately determined throughout the site?
Is there a discernable controlled access zone clearly established?
Are all exposed employees adequately trained and authorized in the appropriate design, safe installation and use of slide guards?
Are all the eave edge slide guards continuously and securely installed?
Is adequate housekeeping maintained in the area of the slide guards and access routes to them, including limiting material storage, and debris removal?
Is the 6-foot clearance rule observed at the gable ends and hip rafters?
Another myth appears to come in the form of inconsistent citations. The fact is that it is possible that the employer can be in literal compliance with the STD, but still may receive a violation. Several compliance officers (in more than one OSHA region) informed me that it's their interpretation that once the roof decking has been secured to the rafters (or trusses) all the way up to the ridge (or hips), that an adequate structural diaphragm has been established. As one officer stated: "The roof is now capable of supporting a complete personal fall arrest system for all the workers continuing to work on the roof and that's what I expect." In other words, once the roof has been decked, it may be a potential violation for the roofer to use slide guards for fall protection while placing underlayment and shingles, even though the STD clearly states that roofing work in Group 4 may be include "removal, repair or installation of weatherproofing roofing materials such as shingles, tile or tar paper."
The roofing trade now has a wide range of ANSI-approved roof anchoring and retractable lifeline devices available which enable employers to practically and readily protect their roofers well beyond the low-level precaution provided by slide guards. OSHA inspectors know this fact, and, regardless of the STD, many consider lack of PFAS at that phase tantamount to a 5(a)(1) General Duty clause violation. When we look at it logically, it may make sense to protect your workers to a higher level as soon as it is feasible, not just affordable.
Myth #8: There's Nothing to TrainA training plan agenda, covering all of the observed hazards and your employer's means to control or eliminate them, should always be designed, delivered, implemented and verified by the employer's designated qualified person trainer. Fall protection and controlled access zone training should be provided to any and all roofing personnel who may potentially be exposed to slide guards in the course of the daily, residential roof work. Anyone without adequate training should be prohibited from working in the controlled access zone. In most cases I've seen, there is no training for the new hire or day laborer. Even the experienced journeyman knows little about the proper use, design and limitations of slide guards.
The final myth is that everyone understands the proper use of slide guards and other fall protection techniques by, what I call, "plywood osmosis." They'll just figure it out after awhile or they won't. As their employer, take the time to thoroughly explain the equipment, site-specific procedures and answer any questions they may have before they're exposed to slide guards and their inherent hazards. I know they look simple enough, but slide guards are easily taken for granted and their limitations ignored. The nature of this alternative FP system falls somewhere between administrative and engineering controls. Market pressure and congressional debate had obvious effects on this STD's regulatory acceptance. The fact of the matter is contained in the descriptive term "slide." You can't teach a roofer to slide.
Most roofers working without the benefit of PFAS or guardrails who actually fall off the roof eaves, spend some of their descent time sliding on either their backs or stomachs. But there are a considerable number of positional falls involving 1) "lateral rolls" and 2) head-over-heel "full tumbles." Without PFAS these victims may actually incur little or no protection from a compliant guardrail system, let alone a row of 2-by-6 slide guards down at the eave. Whenever we slide, roll or tumble down a slope, we tend to overcome surface friction, accelerate and develop a squared-ratio mass. Something as simple as a black knot, dry rot or insufficient or careless nailing of the guards may be the direct cause of the fatal or serious fall that occurs as a result of slide guard failure.
When a 250-pound roofer hits boots-first into a slide guard without absorbing the impact with timely knee bend, his mass can convert easily into more than 1,000 psi. This depends on many factors including the time duration of his slide, small diameter debris (accelerant), and the pitch of the deck. Nothing but the best will do at that moment.
ConclusionSince its last 1998 revision, the OSHA Fall Protection Standard has been the primary reference point for construction employers' fall protection plans across the 50 states, Puerto Rico and the Virgin Islands. Its purpose is to eliminate or diminish those injuries and deaths occurring due to insufficient fall protection. The general construction industry, and roofing in particular, has a preponderance of hazardous conditions simply created by the work itself. It takes a well-trained and experienced crew to be aware of and control these hazards as they relocate, change shape, disappear and reappear without warning. While falls still contribute to one third of construction fatalities and 40 percent of those fatalities originate from a roof, it would seem obvious to even a "sidewalk superintendent" that everything possible must be done to eliminate these regrettable accidents. This includes the occasional implementation of alternate fall protection systems such as slide guards and safety monitors.
As an employer, you must constantly be aware of your jobsite conditions and ensure that the most protective hazard abatement procedures are practiced by the most experienced, well-trained and well-equipped personnel available. While under specific conditions, slide guards may comply with the letter of the law; it is a reasonable conclusion that they may lack even the most basic elements of either "prevention" or "protection." The employer who implements them as an alternate fall protection system should thoroughly understand his/her duty to provide a rooftop work site which is free from any recognized, physical hazard, such as a 24-foot fall from an 8:12 pitch roof. While sometimes slide guards may be a minimum level or protection on a roof, make sure you also encourage the supplemental use of guardrails and PFAS as well. My basic recommendation is to use slide guards whenever they're considered necessary precautions but never depend on them for prevention. Regrets can be hard to express to a spouse or child of a worker whose death or injury may have been prevented by something as simple as adequate fall protection.