Flat Roof Cleaning and Fall Protection: What OSHA Requires on a Low-Slope Roof

Flat roof cleaning puts a crew on a low-slope roof, and OSHA sets the required protection by how far from the roof edge the work happens: under 6 feet, 6 to 15 feet, or 15 feet and more. The duty belongs to the cleaning company as the employer. Here is what the federal rule says, with links, and what a property manager can ask before the crew goes up.

We are a pressure washing company, not lawyers or safety consultants. This is a plain-English summary of the federal rule, with links. Ask OSHA, your attorney or your insurer how it applies to your property and your contractors.

Whose duty it is

OSHA’s general industry rule on falls “requires employers to provide protection for each employee exposed to fall and falling object hazards”^[1]. On a roof cleaning job, the employer is the cleaning company, so the duty to protect the crew is the cleaning company’s. A property manager is still the one who lets the crew onto the roof, which is why it is worth knowing what the rule asks for and asking about it before the work starts.

What counts as a low-slope roof

OSHA defines a low-slope roof as one with a slope “less than or equal to a ratio of 4 in 12 (vertical to horizontal)”^[2]. A flat commercial roof falls in that group. The general rule for any walking-working surface is that an employee on an unprotected side or edge 4 feet or more above a lower level must be protected from falling^[1]. Low-slope roofs have their own section that sets the protection by distance from the edge^[1].

The three distances from the roof edge

• Less than 6 feet from the edge. The employer must protect each employee by “a guardrail system, safety net system, travel restraint system, or personal fall arrest system”^[1]. No exceptions are listed for this zone.
• At least 6 feet but less than 15 feet from the edge. The same four systems apply, and “The employer may use a designated area when performing work that is both infrequent and temporary”^[1].
• 15 feet or more from the edge. The employer must protect each employee by one of the four systems or a designated area, but is “not required to provide any fall protection, provided the work is both infrequent and temporary”^[1]. In that case the employer must also “implement and enforce a work rule prohibiting employees from going within 15 feet (4.6 m) of the roof edge without using fall protection”^[1].

Cleaning a whole roof means working right up to the edge, the parapet and the drains along it, so the job includes work within 6 feet of the edge.

What a designated area is

A designated area is “a distinct portion of a walking-working surface delineated by a warning line in which employees may perform work without additional fall protection”^[2]. OSHA’s criteria for the warning line are specific^[3]:

• It is a rope, wire, tape or chain with a minimum breaking strength of 200 pounds^[3].
• Its lowest point, including sag, is not less than 34 inches and not more than 39 inches above the roof surface^[3].
• It is “clearly visible from a distance of 25 feet (7.6 m) away, and anywhere within the designated area”^[3].
• It is set up not less than 6 feet from the roof edge for work that is both temporary and infrequent, or not less than 15 feet for other work^[3].
• Employees stay inside the designated area while the work is underway^[3].

A travel restraint system, one of the other options, is an anchorage, connector, lanyard and body support that an employer uses “to eliminate the possibility of an employee going over the edge”^[2].

Skylights and roof openings

The rule also covers holes. The employer must protect each employee from falling through “any hole (including skylights) that is 4 feet (1.2 m) or more above a lower level”, by covers, guardrail systems, travel restraint systems or personal fall arrest systems^[1]. On the roof, skylights and roof hatches are part of the job site.

Before

After

Left: before. Right: after. A flat commercial roof we cleaned. The two photos were taken from different spots on the roof.

What a property manager can ask before the crew goes up

• How will you protect your crew near the edge? The rule names guardrails, safety nets, travel restraint and personal fall arrest for work within 6 feet of the edge.
• Will you use a designated area, and where will the warning line go? It has to be at least 6 feet from the edge for temporary and infrequent work, and at least 15 feet for other work.
• How will skylights and roof hatches be covered or guarded?
• How do you get on the roof, and where will equipment and hoses sit? Agree on it before the day of the job, along with which roof access you will open for them.
• Where will the wash water go? Roof drains lead somewhere. Our wash water guide covers what Sarasota and Manatee County rules say about storm drains.

Cleaning flat roofs is part of our commercial roof cleaning in Sarasota, alongside our strip center pressure washing. Both are part of our commercial pressure washing in Sarasota. Our flat roof before and after shows a real roof job, and our guide to rainy season, salt and humidity covers what Southwest Florida’s weather does to commercial buildings.

Sources

1. 29 CFR 1910.28, Duty to have fall protection and falling object protection (eCFR)
2. 29 CFR 1910.21, Scope and definitions (eCFR)
3. 29 CFR 1910.29, criteria and practices for warning lines and other protection systems (eCFR)