Rooftop Snow Removal: How to Avoid Damaging the Roof System

Snow removal can reduce one building concern while creating another. Traffic, dragged equipment, concentrated stockpiles, hidden roof details, and force applied to frozen materials can damage a commercial roof assembly if the work is treated as a general groundskeeping task.

This guide is about protecting the roof system before, during, and after snow removal. It is not a removal procedure, a structural assessment, or a safe-work plan. Decisions about whether removal is required, how snow loads should be managed, whether the building may remain occupied, and how workers can safely access the roof must come first from the responsible owner, employer, prime contractor, structural engineer, and other qualified parties for the site.

Put Safety and Structural Decisions First

Snow-covered roofs can conceal edges, openings, skylights, trip hazards, electrical equipment, weak areas, and changes in elevation. WorkSafeBC's snow-removal planning guidance calls for a risk assessment, written procedures, trained workers, suitable controls, and a rescue plan. It also says roof-load limits and the risk of creating an unbalanced load need to be addressed.

Those are not roofing-maintenance decisions. A roofing contractor can identify the membrane, vulnerable details, drainage features, and appropriate protection or repair methods, but should not be assumed to approve structural loading or another contractor's work-at-height plan. If loading, deflection, cracking, movement, or building stability is in question, follow the direction of the responsible structural professional and emergency authorities.

WorkSafeBC's broader falls-from-elevation guidance emphasizes eliminating work at elevation where possible and using site-specific controls where it cannot be eliminated. A roof-protection checklist does not replace those controls.

For seasonal planning before an event, see Raven's guide to commercial roof snow and ice management in Sea-to-Sky. For access and fall-hazard coordination, review commercial roof safety for property managers.

Give the Snow-Removal Team a Roof-Specific Briefing

Before access, provide the qualified removal contractor with more than an address and roof hatch location. The briefing should identify, where known:

• The roof-system and membrane type, including different systems on separate roof areas
• Approved access points and designated travel routes
• Drains, scuppers, overflows, gutters, and intended drainage paths
• Curbs, parapets, expansion joints, seams, flashings, and membrane transitions
• Skylights, hatches, vents, pipes, conduits, anchors, cables, and other penetrations
• Known fragile, damaged, repaired, wet, restricted, or warranty-sensitive areas
• Rooftop equipment, screens, supports, sensors, and components concealed by snow
• The building contact, stop-work contact, and process for reporting roof contact or damage

A current roof plan and labelled photographs can make this information easier to use when snow obscures the surface. Markings are only helpful if their meaning remains visible and has been explained to the crew; they should not be treated as a substitute for hazard assessment or direct coordination.

The building team should also review the actual roof-system documents. Manufacturer instructions and warranty conditions vary. For example, Sika Canada's Sarnafil roof-maintenance guide includes system-specific cautions about snow and ice removal, traffic, penetrations, drains, and qualified repair. Its directions apply to the systems and documents it covers; another assembly may require different controls. The executed warranty and the current instructions from the applicable manufacturer or issuer govern.

Establish Routes, Limits, and Sensitive Zones

The plan should distinguish the access route, work zones, temporary snow locations, discharge areas, and no-go zones. These locations require coordinated review because moving snow changes loading and can expose or bury roof features. A structural professional should resolve loading and stockpiling questions; the roofing party should identify membrane and detail-protection concerns; the safety lead should control worker and public hazards.

Within that reviewed plan, protect the roof by setting clear boundaries around:

• Membrane seams, patches, wrinkles, blisters, and previous repairs
• Drain bowls, strainers, scuppers, overflow openings, and gutters
• Base flashings at walls, curbs, and penetrations
• Expansion joints and roof-to-roof transitions
• Skylights and other fragile or fall-through surfaces
• Pipe boots, conduits, cables, small vents, and low equipment supports
• Areas without permanent walk pads or other suitable traffic protection

Keep travel and staging on the reviewed route. Repeated foot traffic can abrade surfaces or stress existing defects, especially when workers cannot see the membrane. Temporary protection should be selected for the actual roof system, temperature, traffic, duration, and site conditions. Improvised protection can shift, create a trip hazard, trap moisture, or introduce sharp edges.

Raven's guide to managing third-party contractors on commercial roofs provides a broader authorization and closeout framework for outside contractors.

Protect Drainage Without Forcing the System

Snow removal and drainage planning need to work together. Do not use drains, scuppers, gutters, or rooftop equipment as dumping points. Packed snow, ice, and debris can obstruct flow, damage strainers or flashings, and send water where the roof was not intended to receive it.

Maintain the drainage paths identified in the site plan, but do not assume that a frozen or concealed drain can be cleared by force. Chopping, prying, striking, or applying an unreviewed product near a drain can damage the membrane, drain connection, coating, sealants, or adjacent equipment. Refer the condition to the roofing contractor and follow the roof-system manufacturer's current instructions.

RCABC's roof-maintenance guidance identifies drains, physical damage, punctures, traffic, and membrane-compatible repairs as maintenance concerns. It also warns that significant snow, ice, or water loading may require urgent occupant and structural action. The article is a useful roofing reference, but it does not replace a project-specific engineering or safety decision.

Watch for Puncture, Abrasion, Flashing, and Impact Damage

Damage may not appear as an obvious open hole. During the work and closeout review, look for changes such as:

• Cuts, punctures, gouges, or crushed areas
• Scuffing, scraping, worn surfacing, or displaced aggregate
• Open seams or disturbed patches
• Wrinkled, pulled, split, or displaced base flashing
• Bent drain components, missing strainers, or damaged scuppers
• Contact marks or cracks at curbs, penetrations, supports, and equipment
• Displaced walk pads, pavers, ballast, protection, or rooftop components
• New debris, fasteners, fragments, fluids, or materials left on the roof

Cold roofing materials may respond differently to traffic and impact than they do in warm conditions. That is another reason to use the assembly-specific instructions rather than a universal tool or removal rule. If contact occurs, stop work in the affected area when appropriate, identify the location, photograph it, and notify the assigned building and roofing contacts promptly. Do not cover or improvise a repair that could obscure the condition or introduce incompatible material.

Build a Useful Pre- and Post-Work Record

Photographs help distinguish pre-existing conditions from changes during the work. Before removal begins, capture wide views and close-ups of the access point, route, work zones, drains, curbs, penetrations, flashings, equipment, previous repairs, and visible defects. Link the images to a roof plan or other location reference.

After the work, repeat the same views as conditions permit. Record:

• Date, time, weather, roof area, contractor, and site contact
• Access route, controlled zones, and protection used
• Areas where snow was temporarily located or discharged under the approved plan
• Drainage features and rooftop details exposed during the work
• Any contact, impact, spill, displacement, or suspected damage
• Temporary measures, restricted areas, and required follow-up

Photography documents visible conditions; it does not prove that concealed components are undamaged or that the roof is watertight. The same limitation applies to a general walk-through.

Arrange Roofing Review and Compatible Repair When Warranted

A post-removal roofing inspection is particularly useful when the membrane was contacted, a concealed detail was struck, flashings or drainage components moved, unplanned routes were used, damage is suspected, leakage appears, or the owner needs a documented condition record after a significant event.

The inspector should identify the roof system, document the affected area, and determine whether further investigation or repair is appropriate. Repair materials and methods must be compatible with the existing assembly and must follow applicable manufacturer, warranty, design, and project requirements. A temporary measure should be recorded and followed by a permanent repair plan where required.

Raven provides commercial roof inspections and targeted commercial roof leak repairs for buildings in its service area. If snow removal is being planned, has just finished, or may have affected the assembly, arrange a professional roof assessment so the team can document visible conditions and define appropriate roofing follow-up.

Keep the Boundary Clear

Effective rooftop snow-removal coordination has two parallel tracks. Qualified safety and structural parties decide whether, when, and how the work can proceed. Roofing professionals identify how to protect the assembly, document its condition, and complete compatible repairs where warranted.

Keeping those roles clear helps owners avoid turning a structural or access decision into an improvised roofing procedure—and helps prevent necessary snow work from creating a preventable roof problem.