Managing Third-Party Contractors on Commercial Roofs

Commercial roofs are shared workspaces. HVAC technicians, electricians, plumbers, controls contractors, telecom installers, sign contractors, window-cleaning teams, and other vendors may all need access to equipment above the building. Their work may be unrelated to roofing, but their route, materials, tools, and alterations can still affect the roof assembly.

The answer is not to keep every non-roofing contractor off the roof. It is to use a consistent control process: confirm who is authorized, give them roof-specific information, define access and staging limits, review warranty and alteration requirements, record the roof before work, and close out the visit after work is complete.

This guide gives BC owners and property managers an on-page roof-work authorization and documentation framework. It is an operational tool, not a substitute for the contractor's safe-work procedures, the building's legal duties, project contracts, permits, design review, or the actual roof warranty.

Why Non-Roofing Work Can Create Roofing Risk

A contractor can complete its own technical task correctly and still leave a roofing issue behind. Common pathways include:

• Cuts or punctures from sharp tools, fasteners, panels, or discarded parts
• Scuffing or compression caused by repeated traffic, carts, ladders, or heavy point loads
• Damage to membrane flashings when workers lean equipment against curbs or parapets
• Displaced ballast, pavers, walk pads, drain guards, or protective surfacing
• Blocked drainage from packaging, wire offcuts, screws, leaves, or temporary materials
• Spills or contact with substances that may be incompatible with the roof membrane
• Pipes, conduit, cable, or supports laid directly on the roof without a reviewed support detail
• New openings or attachments that bypass the roof system's intended waterproofing details
• Unrecorded work that makes responsibility difficult to establish when a leak is discovered later

RCABC's current roof-maintenance guidance tells inspectors to note rooftop traffic, physical damage, alterations, and new equipment. It also says heavy traffic may require protective traffic pads and that access may need to be limited or directed. Those observations support a simple principle: rooftop work should be managed as a building-envelope interface, even when roofing is not the main scope.

For a closer look at traffic, equipment, and fall hazards, see Raven's guide to commercial roof safety for property managers.

Start With Roof Ownership Information and Access Authority

Before approving access, identify the roof area and the information that governs it. A useful roof file may include:

• Roof plan and access point
• Roof-system type and approximate installation date, if known
• Warranty or guarantee documents and issuer contact information
• Record of previous alterations, repairs, and recurring leaks
• Known restricted, fragile, wet, contaminated, or otherwise hazardous areas
• Designated walkways, protected routes, and permitted staging locations
• Drains, scuppers, overflows, skylights, hatches, fall hazards, and sensitive details
• Building contact and after-hours escalation process

Do not rely on a generic building note such as “contractor may access roof.” Authorization should identify the company, people attending, date or work window, roof area, task, equipment affected, proposed route, materials brought up, and whether the work involves penetrations, attachments, hot work, liquids, heavy loads, or removal of roof components.

Access control also has a safety dimension. WorkSafeBC's roles and responsibilities guidance explains that owners, employers, supervisors, prime contractors, and workers have distinct duties. At a multiple-employer workplace, the owner may be the prime contractor unless another party is designated through a written agreement; each employer still retains responsibility for its own workers. The correct roles should be established for the specific workplace and project rather than inferred from a roof-access form.

WorkSafeBC also states that fall protection is required where a worker could fall 3 metres or more, or from a lesser height where serious injury could result. The visiting employer and project team should determine the site-specific controls, training, supervision, weather limits, rescue planning, and regulatory requirements. A property manager's sign-in sheet does not make an unsafe roof safe.

Use a Pre-Work Roof Authorization Check

The building's authorization process should happen before the contractor mobilizes. For routine service, it may be a short standardized review. For alterations, lifts, structural questions, or overlapping trades, it may need formal project coordination and input from qualified professionals.

Scope and people

• Company, site supervisor, workers attending, and contact numbers are recorded.
• The exact equipment, roof zone, and work scope are identified.
• The owner or project lead has confirmed the relevant procurement, insurance, credential, and site-access requirements.
• The party coordinating the workplace and other affected contractors is identified where applicable.
• Tenant, shutdown, noise, odour, security, and interior-access impacts have been addressed by the responsible project parties.

Roof and warranty

• The roof system and applicable warranty or guarantee documents have been located where possible.
• The issuer's notification, authorization, installer, material, inspection, and documentation requirements have been checked for the proposed work.
• Existing leaks, repairs, vulnerable areas, and nearby drainage features have been disclosed.
• A roofing contractor has reviewed any proposed penetration, curb, flashing, membrane removal, support, or roofing tie-in.
• Structural, mechanical, electrical, code, or design questions have been assigned to the appropriate qualified party.

Warranty requirements are project-specific. As one example, Sika Canada publishes its current roofing warranty forms; its sample terms show that alterations, repairs, and equipment placed on or through a completed roof can affect coverage when required written authorization is not obtained. That example should not be treated as the rule for every system. The building's executed documents and the issuer's current instructions control.

Access, protection, and weather

• The access point and travel route are marked or explained.
• Edge, opening, skylight, electrical, chemical, weak-deck, and other known hazards have been communicated to the appropriate parties.
• Temporary surface protection is compatible with the roof and suited to the planned traffic or staging.
• Loads, carts, ladders, tools, removed parts, and materials will be kept within reviewed locations.
• Drains, scuppers, overflows, and intended drainage paths will remain unobstructed.
• The responsible contractor has set conditions for postponing or stopping work because of weather or other hazards.
• A weather-tight sequence and contingency have been assigned if the roof assembly may be opened.

Temporary protection should not be improvised blindly. Some boards can have sharp edges, some mats can trap heat or moisture, and incompatible products may stain or affect a membrane. The protection method should fit the roof system, surface condition, load, duration, and work method.

Define Routes, Staging Limits, and Housekeeping Rules

The route from the hatch or ladder to the work area deserves as much attention as the equipment location. A worker carrying a replacement motor or metal panel may take a shorter path than the one shown unless the route is clear and practical.

A roof-use plan can identify:

• Approved access point and travel path
• Existing walk pads or temporary protection
• No-go areas and fragile or damaged locations
• Material staging and waste collection areas
• Areas where tools or components should not be placed
• Drainage features that must remain clear
• Locations requiring a roofing escort or other building-specific control

Protection is not permission to overload the roof. Questions about concentrated loads, equipment weight, pallets, hoists, rolling loads, or deck capacity should be referred to the responsible structural or design professional. Likewise, a roofing contractor can advise on membrane protection and waterproofing interfaces but should not be assumed to approve another trade's safety method or structural loading.

Housekeeping expectations should be explicit. Contractors should account for screws, wire, sheet-metal fragments, packaging, sealant tubes, liquids, and removed components before leaving. Magnets can help collect ferrous fasteners but will not find every sharp object. A visual sweep of the route, work zone, and nearby drains is still useful.

Do Not Let New Penetrations Become Field Improvisations

A penetration should not be considered complete when another trade has merely passed a pipe, conduit, cable, or duct through the roof. The opening, control layers, support, flashing, termination, and surrounding drainage should also be addressed under the coordinated design and trade scopes.

Before any opening is made, resolve:

• Exact location and clearance from drains, walls, curbs, seams, and other penetrations
• Roof assembly and concealed-condition questions
• Structural opening, reinforcing, attachment, and support requirements
• Air-, vapour-, thermal-, and water-control continuity where applicable
• System-compatible curb, boot, sleeve, flashing, or other detail
• Roofing contractor, manufacturer, consultant, or design-authority involvement required by the project
• Temporary dry-in and interior protection if permanent completion is delayed
• Final inspection, photographs, drawings, and warranty records

Raven's roof penetration management guide explains these interfaces in more detail. For equipment replacements, the rooftop HVAC replacement guide covers curb, crane-day, condensate, and closeout coordination.

Avoid treating exposed sealant as a universal flashing solution. The appropriate detail depends on the membrane, penetration geometry, movement, support, manufacturer instructions, applicable standards, warranty terms, and project design. Where the work changes the roof, involve the appropriate roofing party before the opening is created rather than asking for a patch after another trade has demobilized.

Record Conditions Before and After Work

Pre-work photographs provide a condition baseline; post-work photographs help show what changed. Neither proves that concealed conditions are sound or that future leakage cannot occur, but a consistent record can make follow-up faster and reduce avoidable disputes.

Photograph:

• The access point and full travel route
• Wide views of the work area from more than one direction
• Existing damage, patches, stains, debris, ponding, or displaced components
• Flashings, seams, curbs, penetrations, supports, and drainage near the scope
• Temporary protection and staging after setup
• The finished work, adjacent membrane, route, and drains before demobilization

Keep the original files with their dates and link them to the roof area, work order, contractor, and equipment asset. Do not rely only on close-up images; without a wide location view or roof-plan reference, a later reviewer may not know where a defect was photographed.

The building's access log can use these fields:

Record field	What to capture
Visit	Date, arrival/departure time, company, workers, and building contact
Scope	Roof area, equipment ID, task, and approved work-order reference
Interfaces	Penetrations, attachments, liquids, hot work, lifting, loads, or roof components affected
Controls	Access route, protection, staging limits, warranty steps, and coordinating contact
Condition	Pre/post photo links, existing observations, changes, debris, spills, or damage
Closeout	Work completed, temporary items, deficiencies, responsible party, and follow-up status

Sika Canada's commercial roof maintenance guidance recommends keeping a roof plan, access and warranty information, prior reports, and details of changes to the roof system and rooftop equipment. The same information makes a third-party access log more useful than a simple list of names.

Close Out the Roof Visit, Not Just the Trade's Work Order

The equipment may be running and the contractor's task may be complete while roofing deficiencies remain. Before access is closed, the property manager or assigned project lead should confirm, at a level appropriate to the work, that:

• Workers, tools, unused materials, removed parts, and waste are off the roof
• The travel route, staging area, and work zone have been reviewed
• Drains, scuppers, and overflows are clear of project debris
• Temporary protection has been removed unless it is documented and intended to remain
• Spills, cuts, punctures, displaced components, or other observed changes are recorded
• New penetrations, curbs, supports, and roof tie-ins have the required roofing closeout records
• Temporary conditions and open deficiencies have an owner, status, and follow-up date
• The roof plan, equipment register, warranty file, and maintenance history have been updated where appropriate

The depth of review should match the risk. A routine filter change may need a route check and log entry. A new curb, heavy lift, solar attachment, or multiple-trade alteration may require roofing review, design input, field observations, testing, or manufacturer involvement under the project documents. A post-work visual review should not be presented as a guarantee of watertightness or acceptance by a manufacturer, consultant, authority, or owner.

If damage is observed, protect people and the building first, stop affected work where appropriate, photograph the condition, preserve relevant materials and records, and notify the assigned building and project contacts. Emergency measures should use compatible methods where feasible and be followed by a permanent repair plan from the appropriate roofing party.

Make Roof Access a Repeatable Building Process

Managing third-party contractors works best when the same basic controls apply to every visit: authorization, roof-specific information, warranty review, access route, protection, pre-work record, roofing coordination for penetrations, housekeeping, post-work review, and documented closeout.

That process cannot eliminate every leak, accident, warranty dispute, or concealed condition. It can, however, help property teams identify interfaces earlier, preserve a clearer roof history, and bring the right parties into alterations before the roof is opened.

For buildings with frequent rooftop traffic or planned equipment work, Raven Roofing can review the roof-related scope and help define appropriate inspection, maintenance, or commercial roof alteration coordination for the specific system and project.