The Demolition Plan: Reading Load Paths & Writing the Sequence

Welcome

Hello, and welcome. This is Super Structures General Contractors — a national general contractor headquartered in Powhatan, Virginia — here to help you and your clients build something that lasts. We're glad you're with us, and we look forward to connecting with you.

Alright, The Demolition Plan: Reading Load Paths & Writing the Sequence. Don't let the plain title fool you. Here's the part that actually matters on the job: A demolition plan is a written answer to one question, what holds what up and in what order it can come apart, and the engineering survey is where that answer gets built. Learn it well and you will never remove a member you cannot account for, which is the only way a building comes down on your schedule instead of its own.

The intro course told you that OSHA 1926 Subpart T requires an engineering survey by a competent person before demolition starts. This lesson is about doing that survey well and turning it into a plan a crew can actually follow.

What the survey actually examines

1926.850(a) asks for the condition of the framing, floors, and walls and the possibility of unplanned collapse of any portion of the structure. In the field that means walking every level with the original drawings when they exist and a flashlight when they do not, and answering a short list for every bay:

• What is the gravity load path from roof to footing: which walls and columns carry, which are partitions, and where beams and girders bear.
• What provides lateral stability: shear walls, braced frames, masonry infill, or simply the floor diaphragms tying walls together. Remove the diaphragm and a tall masonry wall is a free-standing panel.
• What condition it is in: rot at sill plates, corroded bar in spalled concrete, fire-damaged steel, undermined footings, unpermitted alterations that cut things.
• What has changed since it was built: added rooftop units, removed walls, infilled openings, a mezzanine nobody drew. Adjacent structures where employees could be exposed get the same inspection, and the employer keeps written evidence of the survey.

Reading the framing type

Each framing system fails in its own way, so the plan is different for each:

• Wood frame comes apart easily but hides bearing walls behind drywall. Confirm bearing by following joist direction and looking for girders, posts, and doubled joists.
• Steel frame stays stable until bracing or connections are cut. Members are cut and lowered under control, not dropped (1926.858).
• Cast-in-place concrete is monolithic; cantilevers and transfer beams carry more than they look like, and post-tensioned slabs store energy in the tendons.
• Precast and tilt-up depend entirely on connections. A panel released from its connections falls as one piece.
• Masonry bearing wall buildings depend on floors for lateral support. 1926.854 does not allow a wall section more than one story high to stand alone without lateral bracing unless it was designed to. The survey names the framing type on every level, because mixed buildings are the norm after a century of additions.

Adjacent structures and the pre-condition survey

Party walls, shared foundations, and buildings within the fall or vibration zone are surveyed before mobilization: photographs of every face and interior wall you can access, existing crack maps, and crack monitors on anything already moving. The survey is given to the neighbor and kept in the file, because a claim filed after demolition is settled by comparing the record to the complaint. Where a party wall will be exposed, the engineer details what stays, how it is braced, and how it is weatherproofed.

Writing the demolition plan

The plan is a document, usually ten to thirty pages on a commercial job, and it contains:

• Survey findings with photos and marked-up drawings.
• The sequence, level by level and bay by bay, with the rule from 1926.850(j) built in: exterior walls and floors come down story by story from the top.
• Temporary support and bracing with the engineer's design where any bearing element is removed before the structure above is gone.
• Equipment and where it may work, with floor capacities for anything placed on a suspended slab (1926.856).
• Debris routes and drop zones, chutes, barricades, and floor-load limits for stored debris (1926.857).
• Utility status, hazmat clearance status, dust, noise, and vibration controls, and emergency procedures.
• Who the competent person is and when they inspect. The plan goes to the general contractor, the structural engineer when one is involved, and every foreman on the crew.

Continuing inspections as the building changes

1926.859(g) requires continuing inspections by a competent person as work progresses, because the structure surveyed on Monday is a different structure on Thursday. The competent person walks the site at the start of each shift and after every significant removal, looking for walls that lost their lateral support, floors that lost a bearing line, debris piles above floor capacity, and weather damage to anything left standing overnight. Findings go into the daily log and, when they change the sequence, into a revised plan.

Going Deeper (Intermediate)

The survey decides when you need a structural engineer. Non-structural strip-outs and total teardowns of simple single-story buildings usually do not. Any removal of a bearing element with structure remaining above it, any building damaged by fire, flood, or impact, any party wall, and any condition the competent person cannot explain all do. The engineer designs the temporary support and signs the sequence; the competent person still owns the daily inspection and stop-work authority.

Old drawings are useful and dangerous. A set from the 1960s shows what was built then, not the three renovations since. Treat drawings as a hypothesis and verify by opening ceilings and chasing loads with your own eyes.

Advanced / Pro-Level

Pros write the sequence so the structure is always stable on its own at the end of every shift. They identify the critical members, the ones whose removal changes the behavior of everything around them, and schedule those removals at the start of a day with the engineer or competent person present, not at 3:30 on a Friday. They size exclusion zones for any planned collapse or pull-over to the height of the element and more where it can roll or bounce, and they stage machines with a clear retreat. They photograph each stage so a later question about what was removed when has an answer. On buildings with unknown conditions they open exploratory holes before pricing the job, because a transfer girder hiding above a ceiling turns a two-day job into an engineered shoring project.

Practice Challenge

A four-story 1920s masonry bearing-wall building with wood floors will be taken down to grade, and a three-story occupied building shares its east wall. What does the plan need beyond the standard top-down sequence? (Answer: an engineer's design for bracing the party wall as each floor that supported it is removed, since the floors are the masonry wall's lateral support; a pre-condition survey with photos and crack monitors on the neighbor; a sequence that removes the floors in a way that never leaves the shared wall or any free wall more than one story unbraced; weatherproofing and permanent bracing details for the party wall once exposed; and vibration limits and monitoring at the neighbor.)

In Practice

A competent person who walks every level with a flashlight, marks the bearing lines on the drawings, and writes a sequence the foreman can read runs a job where the building comes down one planned piece at a time. One who glances at the exterior and says the building looks fine finds the mezzanine nobody knew about when the floor under the excavator starts to sag.

Common Mistakes to Avoid

• Treating the engineering survey as a form to sign instead of a structural investigation
• Trusting old drawings without opening ceilings and verifying the load path
• Writing a sequence with no accounting for the lateral support of masonry walls
• Skipping the pre-condition survey of the neighbor and losing the later claim
• Surveying once and never re-inspecting as the structure changes

Takeaway: A demolition plan is a written answer to one question, what holds what up and in what order it can come apart, and the engineering survey is where that answer gets built.

Educational content only — not structural engineering, a demolition plan, an engineering survey, or hazardous-materials advice, and not a substitute for hands-on training, a competent person, or a licensed engineer, asbestos inspector, or abatement contractor. Follow OSHA 29 CFR 1926 Subpart T and the silica, asbestos, and lead standards, the EPA asbestos NESHAP and your state's hazardous-materials rules, the building and fire codes as adopted in your jurisdiction, the engineer's temporary-support design for your project, and the manufacturer's instructions for every shore, tool, and machine you use.