Personal Fall Arrest System (PFAS)

A PFAS is designed to safely stop a fall before the

worker strikes a lower level. It includes three

major components: 

A. An anchorage to which the other components

of the PFAS are rigged.

B. A full body harness worn by the worker.

C. A connector, such as a lanyard or lifeline, linking the harness to the anchorage. A rip-stitch

lanyard, or deceleration device, is typically a

part of the system. 

For more information on the requirements for a

PFAS, refer to 29 CFR 1926.502(d).

Remember that for fall arrest systems, workers

must use full-body harnesses. Body belts can

cause serious injury during a fall and so OSHA

prohibits their use as part of fall arrest systems.

Risks During Truss Installation

Accidental falls are the leading cause of death for

construction workers and installing roof trusses

can be particularly dangerous for two reasons: (1)

truss construction usually occurs high above the

ground and (2) trusses are not stable until they

are properly restrained and braced. 

Roof trusses are the highest part of a house

frame, so residential construction workers

installing them can fall and be seriously injured or

even killed. Although personal fall arrest systems

(PFAS) are the most widely used form of fall 

protection in residential construction, they might

not be suitable when workers begin installing roof

truss sections because there may not be a stable

place to attach an anchor. Trusses are designed to

support weight from the top down. Until trusses

are properly restrained and braced, they are weak

if pulled from the side (i.e., subjected to lateral

force) as can occur when a truss-mounted fall 

protection system bears the full weight of a falling

worker. 

PFAS need strong anchor points that can hold the

sudden weight of a falling worker. No anchor with

a single connection point, such as a strap anchor

or a bolt-on anchor, will protect a falling worker

who is attached to a single truss. 

Other systems, such as scaffolds, lifts and ladders

can be used to protect workers until a fully interconnected, multi-truss section has been appropriately braced and secured. 

OSHA requires fall protection measures for residential construction activities 6 feet or more

above lower levels. As a result, employers must

plan ahead to ensure they have the right systems

in place, and that all workers are properly trained

before the job begins. 

FactSheet

Reducing Falls During Residential

Construction: Installing Roof Trusses

Every year, residential construction workers experience numerous fatal injuries due to

falls. Installing roof trusses presents several challenges for protecting workers from

these falls. This fact sheet highlights some of the hazards of truss installation and lists

some practical methods that employers can use to protect workers who install trusses.
How to Reduce Risks

During Initial Truss Installation

Guardrails, nets, or PFAS (conventional fall 

protection) may not be practical for all phases of

truss installation. Instead, employers should plan

to use other methods, such as ground assembly,

scaffolds, aerial lifts, or ladders to keep workers

safe. 

Ground assembly: By assembling a truss section

on the ground, employers can greatly reduce the

risk of falls for workers. A section of trusses can

be sheathed while still on the ground. Peak

anchors and lifelines can be pre-installed before

the section is lifted into place. Many builders find

it efficient to pre-assemble truss sections on the

ground and then lift them with a crane so that

workers can secure the section to the building

frame. 

Lifts: Depending on the building layout and the

tasks involved, lifts (e.g., aerial, scissor) may be

options for setting trusses. Lifts provide a stable,

elevated platform from which workers can operate. Workers must follow all safety procedures

and conduct all operations from inside the lift 

basket. For other requirements for using lifts,

refer to 29 CFR 1926.453, Aerial Lifts. 

Scaffolds: When properly constructed and used,

internal and external scaffolds can provide suitable protection for truss-setting tasks. For example, bracket scaffolds placed on the inside or outside of a building provide large, stable walking

and working areas for workers. To ensure safe use

and appropriate load limits for bracket scaffold

systems, workers should always follow the manufacturer’s instructions or consult a qualified person. For other requirements for scaffolds, refer to

29 CFR 1926 Subpart L, Scaffolds. 

Ladders: For certain truss-setting jobs, platform

and stepladders can provide a stable work platform for workers. They can be particularly helpful

when set up inside a building. Workers should

always use a ladder safely by following the

requirements spelled out in 29 CFR 1926 Subpart

X, Stairways and Ladders. 

Spreader: An engineered spreader, when installed

in accordance with the manufacturer’s instructions, distributes the force of a PFAS across multiple trusses. The roof trusses do not need to be

sheathed to use a spreader. These engineered

anchorage devices are reusable and can be uninstalled and reinstalled quickly. A qualified person

should decide if the spreader is suitable for use as

an anchor.

After a Complete Truss Section Is Fully

Installed

Once the assembled truss section has been set

and secured, it can be used as an attachment

point for an anchorage device. From this point on,

PFAS can be used to protect workers while they

install additional trusses and roof sheathing.

Truss Section

Multiple (typically four) individual trusses that

are interconnected and fully sheathed. A truss

section that has been restrained, braced and

sheathed in accordance with the manufacturer’s

instructions can provide a suitable structure to

establish an anchor point.

Anchors: Fixed anchors provide a secure point

where workers can tie off their lifelines as part of

a PFAS. Anchors for a PFAS must meet the 5,000-

pound strength requirement or maintain a safety

factor of at least two under the supervision of a

qualified person – 29 CFR 1926.502(d)(15). See 

If a worker falls while using a single truss as an anchor point, the whole truss assembly can collapse.

Such a structural failure puts workers’ lives and entire buildings at risk. 
29 CFR 1926 Subpart M, Fall Protection for more

information and additional requirements. 

Different types of anchors for these systems

include, but are not limited to:

• Peak anchors

• Strap anchors

• Bolt-on anchors

Once a group of trusses has been properly

restrained and braced, a roof peak anchor can provide a usable tie-off point for a lifeline. Multiple

peak anchors and lifelines can protect several

workers. After confirmation from the manufacturer, some peak anchors may be strong enough to

serve as tie-off points for two lifelines. Peak

anchors can also be useful for fall protection during later roofing tasks or while setting another

truss section.

Written Fall Protection Plans

If the employer does not use ladders, scaffolds, 

or aerial lifts, and can demonstrate that it is not

feasible or would create a greater hazard to use

conventional fall protection equipment (guardrails,

safety nets, or PFAS) when working at heights of 

6 feet or greater, the employer must develop a

written site-specific fall protection plan in accord

with 29 CFR 1926.502(k). The plan must be 

prepared by a qualified person as defined by 29

CFR 1926.32(m). This person could be the owner,

the supervisor, or a worker who has extensive

knowledge, training and experience with fall protection and is able to solve problems relating to

fall protection. States with OSHA-approved State

Plans may have additional requirements for 

written fall protection plans.

The site-specific fall protection plan must 

document at each location why the use of 

conventional fall protection equipment is not 

feasible or will create a greater hazard. The plan

must also describe the alternative methods that

the employer will use so that workers are 

protected from falls. Workers and their 

supervisors must be trained on the proper use 

of those other fall protection methods. 

Conventional fall protection equipment can reduce

or eliminate the chances of a fatal fall. Written sitespecific fall protection plans ensure that protection

continues, even when conventional fall protection

methods are determined to not be feasible.

OSHA standard: 

29 CFR 1926 Subpart M – Fall Protection 

Available online at

http://www.osha.gov/pls/oshaweb/owadisp.show_

document?p_table=STANDARDS&p_id=10922

OSHA Residential Fall Protection Web Page

http://www.osha.gov/doc/residential_fall_

protection.html

OSHA Compliance Guidance:

Compliance Guidance for Residential 

Construction – STD 03-11-002 (dated 12/16/2010)

Available online at

http://www.osha.gov/pls/oshaweb/owadisp.show_

document?p_table=DIRECTIVES&p_id=4755

State Plan Guidance: States with OSHA-approved

State Plans may have additional requirements for

Residential Roofing within State Plans. For more

information on these requirements, please visit:

http://www.osha.gov/dcsp/osp/statestandards.

html. 

Help for Employers: OSHA’s On-site Consultation

Program offers free and confidential advice to

small and medium-sized businesses in all states

across the country, with priority given to highhazard worksites. On-site Consultation services

are separate from enforcement and do not result

in penalties or citations. Consultants from state

agencies or universities work with employers to

identify workplace hazards, provide advice on

compliance with OSHA standards, and assist in

establishing safety and health management 

systems. To locate the OSHA On-site Consultation

Program nearest you, call 1-800-321-6742 (OSHA)

or visit http://www.osha.gov/dcsp/smallbusiness/

index.html

NIOSH Prevention Through Design

Program

Available online at

http://www.cdc.gov/niosh/topics/ptd
This is one in a series of informational fact sheets highlighting OSHA programs, policies or 

standards. It does not impose any new compliance requirements. For a comprehensive list of 

compliance requirements of OSHA standards or regulations, refer to Title 29 of the Code of Federal

Regulations. This information will be made available to sensory-impaired individuals upon request.

The voice phone is (202) 693-1999; teletypewriter (TTY) number: (877) 889-5627.

DOC FS-3477 9/2011

U.S. Department of Labor

www.osha.gov (800) 321-OSHA (6742)

For assistance, contact us. We can help. It’s confidential.

Occupational

Safety and Health

Administration