Map drains, slopes, penetrations, seams and ponding areas.
V18 — specialized system
Low-slope or flat roof
Treat membrane, insulation, air/vapour control, drains, overflow, parapets and penetrations as one assembly.
Checked: 2026-08-22
Replacing membrane without understanding moisture/insulation can trap a problem below the new roof.
Deflection, major ponding, wet insulation or unknown structure: professional investigation before recover.
Useful tools / data
- Drain/slope plan
- Post-rain photos
- Repair history
What the professional checks
- Assess moisture/insulation/deck
- Design drainage/details
- Verify membrane/substrate compatibility
Sources and limits
Triage prepares decisions and quotes; it does not replace permits, calculations, inspections or regulated trades.
Related path
Continue with the right tools
These links connect this page to the next useful checks and decisions without repeating the full content.
Connect symptoms to the enclosureStart from condensation, staining, odours or movement before choosing a repair.Open →Adapt the enclosure to climateConnect heat, cold, water, wind and wildfire to building priorities.Open →Assess overall resilienceReview water, climate, safety, autonomy and records with a local score.Open →Screen hazardous materialsIdentify situations where work should stop and testing is needed before disturbance.Open →Open climate guidanceReview climate constraints relevant to assemblies and materials.Open →
Tools related to this issue
Explore: Systems to check before closing the work
Systems to check before closing the work
This section connects envelope, air, fire, structure, water and code instead of treating each project in isolation.
Explore: Advanced diagnostics to cross-check
Advanced diagnostics to cross-check
This section connects water, soil, climate, safety, materials and seasonal use to existing projects.
Explore: Specialized systems to cross-check
Specialized systems to cross-check
This section completes gas, soil, water, fire, climate and structural interfaces.
Explore: Edge systems to integrate into the project
Edge systems to integrate into the project
This section covers interfaces that become important when multiple home systems interact.
Explore: Advanced systems and special cases
Advanced systems and special cases
Checks that change sequencing, risk or which professionals must be coordinated.
Explore: Often-overlooked service interfaces
Often-overlooked service interfaces
This section connects systems that cross utility, plumbing, HVAC, envelope and metering boundaries.
Explore: Project risks and overlooked interfaces
Project risks and overlooked interfaces
This section connects payment, water, envelope, ventilation and jobsite details that often create costly surprises.
Explore: Finish and service details to verify
Finish and service details to verify
This section connects small details that become costly once finishes are closed.
Explore: Shared, access and specialized interfaces
Shared, access and specialized interfaces
This section connects projects where multiple systems, owners or rules meet.
Explore: Post-disaster and legacy systems
Post-disaster and legacy systems
This section connects contamination, storm damage, legacy materials and recommissioning before rebuilding.
Explore: V47 interfaces not to miss
V47 interfaces not to miss
These details are small on a drawing but can control water, structure or durability.