A limited access zone for masonry construction should meet which requirements?

The answer

Under OSHA's masonry construction standard, 29 CFR 1926.706, a limited access zone is a controlled area next to a masonry wall being built. To comply, the zone must meet several specific conditions at once:

1. Established before construction begins — the zone is set up before the wall starts going up, not afterward.
2. Runs the entire length of the wall.
3. Extends a distance equal to the wall's height plus four feet on the side of the wall that is not scaffolded.
4. Kept clear of everyone except the workers actively building the wall.
5. Stays in place until the wall is adequately supported to resist overturning and collapse; if the wall is over eight feet tall and not braced, the zone stays until the bracing is in place.

That combination is why, on a multiple-choice exam, the correct answer is the option that captures all of these requirements (often phrased as "all of the above").

Why the dimensions are what they are

The height-plus-four-feet distance is not arbitrary. A freshly laid masonry wall that has not yet cured or been braced is unstable and can topple. If it falls, it falls roughly across a distance related to its height. By clearing a zone equal to the wall height plus an extra four-foot margin, OSHA ensures that if the wall collapses, no unprotected worker is standing in the fall path. The zone is measured on the unscaffolded side because the scaffolded side already has workers and structure the standard treats differently; the open side is where a toppling wall would strike bystanders.

Limiting entry to only the workers building the wall reduces the number of people exposed to that collapse hazard to the essential minimum.

Why the other options are wrong

Common distractors fail because they change one variable:

• "Equal to the wall height" (no extra four feet) — too small; it omits the safety margin OSHA requires.
• "Established after the wall is built" — defeats the purpose; the collapse risk is greatest during and just after construction, so the zone must exist beforehand.
• "Open to all construction workers" — wrong; only those actively building the wall may enter.
• "Only along part of the wall" — wrong; it must run the wall's entire length.

Each single-condition answer is incomplete, which is why the fully correct choice combines them.

The bigger picture

The limited access zone rule exists because unbraced masonry-wall collapses have historically killed and injured workers during construction. The zone is a simple administrative control — a marked, restricted area — that keeps people out of the collapse path until the wall is structurally sound or braced. Understanding the reason (fall-path protection) makes the specific numbers easy to remember: length of the wall, height plus four feet, unstacked side, wall builders only, before construction starts.