Do our employees performing general maintenance tasks on the roof of our facility need fall protection? Our roof has no railing, etc.

Yes! You do need fall protection on a commercial roof for maintenance but how much depends on your sensitivity to protection and the company's awareness of recognized fall hazards.

Can you answer the following questions on Fall Prevention?

q.1 - Can there be a painted stripe on the roof for a warning line?

q.2 - Why does the tensile strength of the warning line have to be so high when the stanchion only needs to withstand 16# of force? This is the standard we design to and force vectors are involved.

A.1. - Painted lines are a problem in a snow belt and obviously where aggregate is on the roof. I prefer painted lines for permit requirement. The warning line if permanent does the trick for the permit closer than 6,10 or 12 ft as necessary. The raised line is a tactile system designed to get the attention of someone backing into an opening or toward an edge. Roofers are notoriously backward walkers in unrolling their material and may not see or comprehend a line when the edge cannot be seen directly.

A.2. - The strength comparison is interesting. 1926.502(f)Warning Lines: 16 lbs vs. 500 lbs. The line has a sag in it depending on length but the lowest point is 34" and highest 39". Therefore the stanchion is tested at 39" to see if the tipping force exceeds 16 lbs. First it should stay upright under reasonable wind conditions (up to 40 mph??), Second when the bow is taken up as a person backs into it the tipping is an event designed to get the notice of the worker before the worker gets too close to the edge. If the fall occurs at 5 ft from the edge, the person should still stay on the surface; however below 4 ft it is doubtful. Thus 10 or 12 ft is more practical a distance from the edge.

Ropes and cables always are rated in excess of their minimum because they degrade. Secondly the ease of having a 500 lbs rope (3/8") or cable (1/4") makes the number work for visibility. The flagging every six feet increases visibility.

The problem of stumbling backwards throws the business of warning lines into a fundamental conflict. 15 ft or more stumbles backwards are not uncommon and one can only hope that a warning line causes the person to fall prone. The best advice is to use a guardrail or parapet for protection.

My question is based on your Tip of the Week #70 that discusses when window cleaners are at 6 feet from the edge and closer. My understanding is that distance doesn't matter, they need fall protection at any distance from the edge. Am I misunderstanding something here?

Window cleaners are part of the general industry regs and other workers typically are construction reg related. Workers typically come back periodically for window cleaning purposes. Therefore 6 ft plus for building edges less than 42" high seems reasonable in normal ambient conditions for window cleaners. Construction folk, including roofers, can wander the length of a building floor or roof to communicate visibly over an edge unless they are constrained by barriers and work rules in the area where their work occurs. OSHA will deal case-by-case with reasonable interpretation of its construction rule to barricade all floor edges or work areas.

What is the proper distance from the roof edge for a warning line?

15 feet from an edge to locate and mark a warning line is an OSHA interpretation which makes sense to me. The recent and long ago interpretations on roof work by non-roofing workers starting with the early one in the third edition of Dr. Ellis' book "Introduction to Fall Protection", indicate that 15 feet makes a non-roofing violator more noticeable than 6 or 10 feet for roofers.

What is the safe distance from a roof edge for those doing work on the roof (not installing the roof)?

None, workers are drawn like magnets to edges but take a look at the OSHA interpretation in Dr. Ellis' book of what is reasonable. You can set up your own procedures which if enforced will be effective and OSHA-acceptable. Be sure to have a review with a compliance officer when you set up.

Iﾒm a member of the Engineering Practice Specialty Group and work in General Industry. Iﾒm not very familiar with fall protection in regards to roofs. We have contractors who have to get on the roof to service air units or make roof repairs. Some of the air units are located about 15 foot from the edge. Can you provide some guidance on regulations and/or best practices for protecting workers from leading edge work hazards?

You can follow OSHA interpretations concerning 15 foot warning line from an edge for non-roofers working on roofs. You can always offer a more protective solution such as a fall arrest system. If your HVAC unit is 15 feet from an edge, you need a space to walk which is at least 3-4 ft closer to the edge than 15 feet and a warning line may not be appropriate for that trade.

I have a flat, corrugated, metal roof at my facility. At the top of our mixing tower, about 5 stories up, there is an emergency escape door. If one were to escape through this door they would walk about 20 feet potentially along the roof edge and then down another ladder to another roof top and again walk about 50 feet potentially along the roof edge to another ladder which would take them to the ground. All several stories above the ground.

An ISO auditor has told us we need guardrails along the edges of the two roofs leading to the ladders.

Now, my questions: Can I use a rope and some posts to guide employees to the ladder safely or does the guardrail have to meet guardrail standards?

No one performs work on this roof without proper fall protection so this is only needed in case of an emergency evacuation of maybe 1 or 2 employees at the most. Vary unlikely that in an emergency they would be at the top of the mix tower and need to escape this way.

The final decision should be made based on a professional hazard assessment. No, you cannot stick up some posts and rope guide for emergency use because an unsteady flexible railing could tip you over especially in a panic situation. Can you use escape systems like the vertical chute already hinted - possibly yes but how many years will this system be up and who will inspect it and provide a regular test run and restore it to readiness? Maybe a cable escape system would be easier for one or two persons and those are under the ASTM E06.77 standard - the committee member list is composed of most of the manufacturers in the world who have held themselves to a very high standard but will the owner adopt those same standards for regular inspection and for how long? For you and your plant operation, I suspect it should be a catwalk and railing meeting A1264.1 and OSHA 1910 regs which will be an investment in your plant capital equipment and will meet the IBC and NFPA 101 exit access and discharge requirements. Also maybe another route is possible depending on the hazard and foreseeable time for egress. Ladders from roof to roof are very suspect to loosening of the bolts to the structure over time so a professional engineer should design the bolting to last for 20 years without pulling loose and also, once up, inspected annually by a competent person following ANSI A14.3 and 1926.1053 and 1910.27.

Over the years I have heard that one must restrict access to roof edges or provide fall protection for persons involved in maintenance work on roofs to a distance of 6, 10, and 15 feet. Today when I searched 29 CFR 1910, I found nothing specific to roofs and fall protection.

If you are aware of specific applicable language in 1910, or if there is a letter of interpretation regarding this type of work I would appreciate hearing from you.

There is nothing in 1910. 1926 however is more helpful eg 501b1, 2, 10, 15 and 501c also 502 f, g, h, j, and 503a. 1910 is dealt with using 5a1 and 2. Also ANSI A10.18 and A1264.1, 2 hit on the same issues.

OSHA often cites standards in the alternative just in case maintenance is really construction or vice versa.

Are workers allowed under OSHA to work between an unprotected edge and the warning line (the warning lines being set up 6 feet from the unprotected edge)? Is that what the safety monitor is for?

I see for low sloped roofs that there are combinations of guard rails and warning lines, safety nets and warning lines, and fall arrestment and warning lines. How do these combinations work, like for guard rails and warning lines? Where there are no guard rails, you would have to use warning lines, but what about work between the unprotected edge and the warning line? Iﾒm just trying to understand what OSHA envisioned with the standard.

No, the workers cannot work between the unprotected edge and the warning line without a positive form of fall protection.

They must stay within the confines of the warning line for this administrative control to be feasible.

The safety monitor is used to ensure that workers do no leave the confines of the warning line boundary.