1926 Subpart Q
Overview
OCCUPATIONAL
SAFETY AND HEALTH 1926
Subpart Q
Overview for Subpart Q
Concrete and Masonry
Q-1 What are the most frequently cited serious violations of the
concrete and masonry construction standard?
- Failure to protect employees from impalement -- rebar not capped
or covered. (1926.701(b))
- Failure to establish a limited access zone (LAZ) to limit the number
of workers in the danger zone where a masonry wall is under construction.
(1926.706(a)(1))
- Failure to brace unsupported section of masonry wall over 8 feet
in height. (1926.706(b))
- Failure to have drawings or plans at the jobsite to indicate jack
layout and formwork placement. (1926.703(a)(2))
Q-2 What are some effective control measures that can be used to
guard rebar so employees cannot fall into or onto the rebar and become
impaled?
- Prevent employees from working in an area where they may fall into
or onto unprotected rebar. If this is not possible, use guardrails or
other fall protection measures as outlined in Subpart M to eliminate
the fall hazard from elevations.
- Rebar can be capped with special protective rebar covers
to keep employees from being impaled. Do not use plastic or paper
cups or tape as a rebar cover because they do not protect workers
from impalement.
- The rebar can be bent (but only when an engineer has approved
this practice) or the rebar can be covered with lumber (e.g.,
a 2" x 4" board).
Q-3 What are some of the effective control measures that can be used
to eliminate the hazard of being in the danger zone to protect employees
from being stuck by flying brick and block in the event of a wall collapse?
- Until the wall has gained sufficient strength that overturning (collapse)
is no longer a hazard, keep employees out of the area where the wall
is being constructed unless they are actually engaged in constructing
the wall. The most effective control measure is to follow the standard
by marking off an area with tape, rope, or chain or any other material
that will indicate to employees that they are not to enter the zone
(area) that has been marked. The zone should be equal to the length
of the wall under construction and extend out a distance equal to the
height of the wall to be constructed plus 4 feet. So if the wall to
be constructed is 10 feet high and 30 feet long, the zone should be
14 feet x 30 feet.
Q-4 What are some of the ways to brace a wall over 8 feet to provide
protection against the hazard of collapse?
- The project engineer or competent person should determine how best
to brace the wall. According to the Magazine of Masonry Construction
(November 1988) a typical masonry wall brace includes a vertical member,
an inclined strut, stakes, and if necessary a strut-brace. Scaffold
planks (2 x 10s) are typically used as the vertical member and the inclined
strut, and 2 x 4s for stakes and strut-brace. 2 x 4s and 2 x 6s are
considered by most experts to be inadequate for vertical members or
inclined struts. All lumber must be in serviceable condition.
- The American National Standards Institute's Standard for Concrete
and Masonry Work, ANSI A10.9-1983 standard recommends that "The support
or bracing shall be designed by or under the supervision of a qualified
person to withstand a minimum of 15 pounds per square foot. Local environmental
conditions (e.g. strong winds) need to be considered in determining
the bracing design. Braces or shores shall be secured in position."
TIPS Keep a copy of formwork drawings and plans at the jobsite for
review by the employer, employees and OSHA compliance personnel. Formwork
must be installed as shown on the drawings or plans.
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