Map Valleys, Eaves, Penetrations and Snow-Slide Zones

Draw the roof map

Number roof planes, valleys, walls, eaves, gutters, downspouts and penetrations so drawings, photos and proposals use the same references.

Trace concentrated water

Record valleys, upper-to-lower discharges, wall intersections and drainage constraints without claiming a detail is adequate.

Inventory penetrations

List current and planned vents, curbs, chimneys, skylights and equipment; require system-specific flashing details.

Map areas below roof edges

Identify entries, walkways, decks, parking, equipment and neighbouring areas that could be affected by water, ice or sliding snow.

Keep retention design qualified

Snow-retention need, layout, attachment and loads are design questions. Ask for the basis and coordinated details.

Plan inspection access

Compare safe access assumptions, debris zones, service routes and maintenance documentation.

Map water concentration

Trace each roof plane to valleys, eaves, gutters, scuppers or lower roofs and mark where snowmelt or rain converges. Require proposal details for transitions and overflow-sensitive areas, including how temporary weather protection works while the existing roof is open.

• Show upper-to-lower roof discharge
• Identify ice-prone shaded edges
• Coordinate gutter and flashing scope

Define snow-movement consequence zones

Record entrances, sidewalks, decks, driveways, mechanical equipment and neighbour areas below sloped metal surfaces. Do not prescribe retention devices from a map; require qualified, system-compatible design evidence tied to loading, attachment and the actual roof geometry.

• Mark occupied routes
• Include future solar or equipment
• Keep attachment evidence with drawings

Audit every penetration detail

List vents, chimneys, skylights, curbs, antennas and planned solar supports by roof area. Ask for curb heights, flashing sequence, compatible materials, movement accommodation and responsible trade, then require photographs before closures conceal the work.

• Use a penetration schedule
• Ban field improvisation without review
• Retain closeout photographs

Publish the critical-detail register

Number every valley, eave, gutter, wall, curb, penetration, lower-roof discharge and area below possible snow movement on the roof plan. For each, identify the accepted detail, responsible trade, temporary weather protection, required substrate evidence and photograph or inspection point. Connect proposed snow-management attachments to exact system data and qualified design. Record access for future clearing or inspection without directing unsafe roof work. The register should remain tied to the final roof geometry and should never be presented as a guarantee against leakage, ice, falling snow or extreme weather.

• Use unique detail identifiers
• Assign trade interfaces
• Show occupied areas below
• Record temporary protection
• Archive concealed-work photographs