Commercial roofing · Planning guide
Commercial Roof Installation in Vancouver: Options, Timelines & Costs
Compare roof options, define the work and prepare for a building specific proposal.
Establish the scope before choosing a roof system
Planning a commercial roof starts with the building and the scope: a new construction assembly, replacement of an existing roof or a possible recover system. Each option requires different investigation and coordination. Use this guide to prepare the questions, documents and operating constraints needed for a clear proposal.
Start with the roof condition, drainage, building use and access. Then compare complete assemblies and the work required to install them. A membrane choice alone does not define the project.
What to bring to the first discussion
Bring the property address and building use, available roof drawings, specifications, photos, leak history and previous repair records.
Identify roof access, entrances, loading and parking areas, material staging space, delivery restrictions and the people who coordinate them.
List drains, scuppers, rooftop equipment, curbs, skylights and wall transitions. Share drawings or existing details where available.
Explain operating hours, sensitive spaces and target dates. Identify who can approve the scope, coordinate other trades and authorize discovered work.
New construction, repair, recover or replacement?
| Project scope | What the work addresses | What must be established |
|---|---|---|
| New construction | A roof assembly coordinated with the new building. | Deck, drainage, insulation, equipment and wall interfaces need a defined design and scope. |
| Local repair | A defined defect and its affected components. | The investigation should explain the cause, surrounding condition and limits of the repair. |
| Recover | Suitable existing components remain beneath a compatible new assembly. | Establish moisture, condition, attachment, compatibility, loading, drainage and applicable requirements. |
| Removal and replacement | The specified existing layers are removed before the new assembly is installed. | Define removal, deck assessment, discovered repairs, disposal and protection while areas are open. |
On smaller screens, scroll across the table to read each column.
New construction and existing roof replacement
For new construction, coordinate the roof with the deck, drainage, insulation, vapour control strategy where required, rooftop equipment and adjacent walls. Resolve those interfaces in the design and scope.
A full removal takes off the specified existing roof layers so the exposed deck and remaining components can be assessed. The proposal should state what will be removed, how hidden damage will be documented and how additional work will be approved. A recover retains suitable existing components and needs its own assessment of moisture, attachment, compatibility, loading and drainage. Neither approach should be selected from price alone.
Signs that call for a roof assessment
Cracking, open seams, shrinkage and repeated leaks justify a closer assessment. The decision to repair, recover or replace should follow the condition of the assembly, the extent of trapped moisture and the cause of the failures. Age helps frame that assessment; it does not establish remaining service life by itself.
Repeated leaks need a documented diagnosis. Compare where water enters, which details have been repaired and whether the same defect keeps returning. Localized defects and wider assembly failures need different scopes.
Standing water should prompt a drainage assessment. Check for blocked outlets, low areas, deck movement and details that obstruct flow. Record the conditions and refer to the proposed system requirements. Ponding alone does not establish that the whole roof must be replaced; the correction depends on the cause and the wider roof condition.
When replacement is appropriate
Replacement becomes a stronger option when the investigation shows widespread deterioration, defects that cannot be addressed within a suitable repair scope, or incompatible existing components. The decision should explain what is failing and why the proposed work addresses it.
Some corrections require access beneath the membrane, but the extent of removal is a project decision. Document the affected areas and compare feasible options before committing to a full replacement.
Assessing a possible recover
A recover may be considered only after the existing assembly and proposed system have been assessed. Establish the condition and number of existing layers, moisture findings, deck condition, attachment, compatibility, drainage, loading and applicable requirements.
The proposal should state what stays, what is removed, what is corrected and what remains excluded. A recover should not be justified solely by a lower initial price, and no fixed extension of service life should be assumed.
Addressing recurring leaks
Ongoing leaks can affect insulation, interior finishes and other building components. Record active leaks and assess the immediate protection needed while a permanent scope is developed.
Keep repair records and compare recurring maintenance with the condition of the assembly. This helps distinguish a roof that remains repairable from one where repeated temporary work is no longer addressing the underlying problem.
Plan for rain, drainage and changing weather
Weather protection during installation
The work plan should identify the area that can be opened and made watertight in each phase, the temporary tie ins, the weather decision point and the person responsible for checking protection. Ask how the building will be protected if conditions change before a section is complete. A tarp alone should not be treated as a complete waterproofing plan.
Seasonal timing and weather stoppages
Weather affects both the programme and the work that can be completed safely in a day. Ask for a schedule that separates investigation, material procurement, site setup, roof installation, inspections and closeout.
Agree how weather stoppages will be communicated and how partly completed areas will remain protected. A target completion date should be accompanied by its assumptions, including delivery dates, access, working hours and discovered repairs.
Drainage design for the actual roof
Drainage design needs to suit the existing deck, the roof assembly and the applicable project requirements. Do not apply one slope figure to every roof or membrane. Where tapered insulation or deck changes are proposed, the drawings should show the intended water paths and identify responsibility for the design.
Identify primary outlets, any required overflow provision and the route water takes when an outlet is obstructed. The proposal should explain whether existing drains and scuppers are retained, modified or replaced, and which trade is responsible for each connection. Sizing and compliance need project specific review.
Compare complete commercial roof assemblies
| Roof system | What the proposal should define | Important planning question |
|---|---|---|
| SBS modified bitumen | Membrane layers, insulation, attachment and compatible flashing details. | Review the proposed application method around combustible or concealed construction. |
| TPO | A single ply membrane with hot air welded seams. | Confirm attachment and securement separately from seam welding; review the complete assembly. |
| EPDM | A rubber membrane with specified seams, attachment and flashing components. | Confirm substrate preparation, compatible details and how future roof work will be handled. |
| Built up roofing | Layers of bitumen and reinforcement. | Establish the existing layers, moisture condition, compatibility and any loading review. |
| Metal | A particular panel and seam system suited to the roof geometry. | Confirm product specific slope requirements, drainage, transitions and penetrations. |
On smaller screens, scroll across the table to read each column.
SBS modified bitumen
SBS modified bitumen is one assembly option to discuss for a commercial low slope roof. The proposal should identify the membrane layers, attachment method, insulation and compatible details rather than describe the job only as “torch on.”
Ask how the specified assembly handles drains, upstands and penetrations, and how the work method will be managed around combustible or concealed construction. Suitability and installation details depend on the selected system and the building.
TPO single ply systems
TPO is a single ply membrane with hot air welded seams. Seam welding and attachment to the roof are separate decisions: a TPO system may use mechanical attachment, adhesion or another specified method. Wind resistance depends on the complete assembly, its securement design and installation, not simply the presence of welded seams.
If a reflective membrane is proposed, request the selected product data and discuss the building’s heating, cooling and insulation needs. Do not assume a fixed reduction in roof temperature or energy bills from membrane colour alone.
EPDM systems
EPDM is a rubber membrane option. Compare the proposed attachment, seams, flashing components and substrate preparation as part of the complete assembly. Ask how repairs and future rooftop work would be handled.
A service life or warranty expectation should come from the specific system and written project terms. Membrane colour alone is not a basis for promising protection from ice dams.
Built up roofing (BUR)
Built up roofing combines layers of bitumen and reinforcement. If it is being retained, recovered or replaced, establish the existing build up and its condition first.
The scope should address wet or deteriorated areas, compatibility with new work and any loading assessment required for the proposed assembly. Multiple layers do not remove the need to investigate defects and protect vulnerable details.
Metal roof systems and geometry
Metal roof suitability depends on the particular panel system, seam design, roof geometry and manufacturer requirements. A minimum slope from one system should not be applied to another.
Before selecting metal, resolve drainage paths, panel lengths, penetrations, transitions and access for maintenance. Compare the specified assembly and lifecycle obligations rather than rely on a universal lifespan or a promise of minimal maintenance.
Different surfaces, different roof details
These separate roof photographs show why the existing surface, adjoining walls and openings belong in the assessment. A photograph alone cannot establish the concealed assembly or its condition.
Commercial roof installation: from assessment to closeout
Step 1: Assessment and planning
Start with the available roof records, visible condition and a clear investigation scope. Depending on the building, that may include openings or moisture testing to establish the existing layers and suspected wet areas. Record the limits of the investigation as well as its findings.
Where loading or structural condition needs assessment, identify who is responsible for that review. The proposal should explain how unexpected deck or moisture damage will be handled before it is concealed by new work.
Step 2: Safety planning and site preparation
Ask for the site specific safety plan, including roof access, fall protection, material handling and protection of people below. The appropriate measures depend on the building and the work; a general list of equipment is not a substitute for a compliant plan.
Plan for occupants as well as the roofing crew. Agree on restricted areas, protection below the work and a communication process for noise, access changes and equipment interruptions.
Step 3: Removal or recover preparation
For a full removal, agree which roof layers will be taken off, where debris will travel and how the building will be protected while the deck is exposed. Include waste handling, any required material testing and the approval process for repairs discovered during removal in the scope.
For a proposed recover, ask how retained layers will be checked for moisture, damage, attachment and compatibility. The scope should identify unsuitable areas to remove, repairs to complete, surface preparation and any separation layer required by the selected assembly. Confirm that drains, edges and penetrations can be detailed before covering the existing roof.
Step 4: Deck repairs and drainage corrections
Deck repairs must suit the actual deck construction, which may differ between buildings. Require photos or other agreed records of discovered damage, an approved repair scope and a clear process for pricing changes before the new assembly covers the work.
Where drainage corrections are proposed, confirm the intended water paths, affected outlets and design responsibility before installing the new assembly.
Step 5: Installing the specified roof assembly
Confirm the complete installation specification before work starts: substrate condition, insulation, membrane layers, attachment, seams and details. Ask which preparation checks and installation inspections will be recorded, who performs them and how areas that do not meet the specification will be corrected before they are covered.
The selected system’s written requirements should govern the work. Request the proposed warranty terms separately, including any installer approval, inspection, registration and maintenance conditions. Installing a named membrane does not by itself establish the warranty available for the project.
Step 6: Flashing, drains and penetrations
At parapets, review how the roof membrane connects to the wall flashing and coping. Ask which existing components will remain, how their condition will be assessed and who is responsible for work at the wall and roof junction.
For rooftop equipment, the proposal should identify the curbs, pipes and other penetrations being detailed. Ask for the selected system’s compatible flashing details, how equipment movement is addressed and which trade handles disconnection or lifting. A pitch pan, boot or sealant is not a universal solution for every penetration.
If skylights are included, coordinate the unit, curb and roof flashing as one scope. Our skylight repair and installation services are a useful next step for discussing the opening and surrounding roof details.
Where ventilation work affects the roof, document the required openings, flashing responsibilities and inspection before the work is covered. Include these interfaces in the closeout photographs and maintenance handover.
Step 7: Final inspection and closeout
Agree on the inspection and documentation requirements before work begins. The selected system and warranty may have conditions for installer approval, inspections, registration or maintenance. Confirm them in writing rather than assume every warranty works the same way.
At completion, review the installed scope against the agreed specification, record outstanding items and collect the required closeout documents. For a property within the City of Vancouver, check the applicable Vancouver Building Bylaw and permit requirements for that project.
Preparation, penetrations and roof edges
These photographs show separate details and stages of work. The sloped roof preparation is distinct from the Massey Street membrane roof details; each needs an assembly suited to the building.
What determines the installation schedule?
Build the duration around the defined scope
A reliable duration needs a defined roof area, assembly and work scope. Compare the proposed sequence for removal, deck work, insulation, membrane, details and inspections rather than assign a fixed number of weeks to each material.
Ask which tasks control the completion date and which can overlap. Access restrictions, occupied spaces, equipment shutdowns, delivery lead times and weather may matter as much as the membrane installation itself.
Factors that change sequencing and duration
Roof size and complexity affect sequencing and duration. Compare the work sequence, not just roof area. Multiple levels, penetrations, parapets, occupied areas and restricted access can require additional phases.
Schedule factors to define:
- Weather interruptions and protection between work phases
- The extent of deck or assembly repairs found during removal
- Access, lifting and coordination around occupied areas
- Permit and inspection requirements for the project
- Material delivery dates and sequencing with other trades
Hidden deck or moisture damage can change the sequence because it must be documented, approved and corrected before new work covers it. The proposal should state how discovered work affects the schedule and who approves changes.
Commercial roof installation costs: compare the full scope
What changes the proposed cost?
Roof area is a starting point for a budget, but two roofs of the same size can require very different scopes. Removal, deck condition, insulation, drainage, details, access and occupied building constraints all affect the proposal.
Compare like for like assemblies and inclusions. A low square foot figure is difficult to assess if it leaves out disposal, moisture repairs, equipment coordination or closeout requirements.
A recover proposal and a tear off proposal are different scopes. Ask what investigation supports each option, what remains concealed, which defects will be corrected and which exclusions remain. Compare the suitability and obligations before comparing the totals.
Identify the cost of deck repairs, insulation, drainage corrections, curbs and penetrations, equipment coordination, safety, access and disposal. Record allowances and exclusions separately so they can be compared.
Compare budgets on the same basis
Request an itemized proposal with the roof area and measurement basis, specified assembly, removal and disposal, deck repair assumptions, insulation, drainage work, flashing and penetrations, safety and access, equipment coordination, inspections and closeout. Identify allowances, exclusions, taxes and the process for approving changes.
The useful question is not only “What is the price per square foot?” It is “Does this price cover the same investigation, assembly, details and responsibilities?” An assessment and defined scope are needed before a project budget can be relied on.
Questions to resolve in the tender or proposal
- Investigation: Existing layers, moisture findings, deck condition, inspection limits and unresolved assumptions.
- Removal or recover: What stays, what is removed, suitability evidence, disposal and protection of retained components.
- Assembly: Named membrane, insulation, vapour control approach where required, attachment and compatible components.
- Drainage: Outlets, water paths, slope corrections, overflow review and named design responsibility.
- Details and interfaces: Curbs, penetrations, parapets, walls and the responsibilities of roofing and other trades.
- Weather protection: Daily exposure limits, temporary waterproofing, tie ins and checks before a weather stoppage.
- Occupied building plan: Phasing, deliveries, safe access, emergency exits, working hours, noise and equipment shutdowns.
- Changes: Evidence for discovered work, pricing basis and written approval before additional work proceeds.
- Closeout: Inspections, outstanding items, photographs, warranty documents and maintenance handover.
Plan the work around tenants and building operations
Occupant protection and site access
Plan occupant protection before mobilization. Define work hours, notice periods, restricted areas, safe entrances, emergency routes and a contact for daily coordination.
Identify overhead work zones, material movement routes and areas below the roof that need barriers or temporary closure. The site plan should reflect the building’s actual use.
Noise, deliveries and working hours
For an occupied building, identify which tasks create the most noise and coordinate them around the building’s operations where practical. Record any working hour limits and notice requirements in the schedule.
Keep emergency exits and required access open. Plan deliveries, lifting, waste removal and temporary parking restrictions before mobilization. The proposal should identify any crane or equipment coordination that depends on another party.
Discuss dust, odours or fumes associated with the proposed work method. Agree who issues notices, which entrances or parking areas are affected, and how occupants can raise an access or disruption concern.
Phasing and daily coordination
Phasing divides the roof into sections that can be opened, completed and protected in sequence. The plan should show each work area, daily waterproofing limits and the transitions between completed and active sections.
For a building with several tenants, coordinate the sequence with access, deliveries, sensitive operations and agreed working hours. The schedule should identify who receives updates and how changes are communicated.
Check warranties, approvals and closeout documents
Read the proposed warranty terms
Manufacturer and contractor warranties address different obligations. Request the actual proposed warranty documents and check the covered work, exclusions, duration, claim process, maintenance obligations and any registration or inspection conditions.
Confirm the workmanship terms in the proposal and identify who to contact if a leak occurs. A headline warranty length does not explain what is covered or what the owner must do to maintain that coverage.
Inspections and the closeout file
Confirm the inspections and approvals required by the selected system, project specification and written warranty. Identify who arranges them and when they must occur.
The closeout file should include the agreed scope and changes, relevant installation photos, product details, inspection records, warranty documents and maintenance instructions. Confirm any transfer requirements from the written warranty rather than assume coverage transfers with a sale.
Vancouver requirements and site safety
For work within the City of Vancouver, use the applicable Vancouver Building Bylaw and confirm the permit and inspection requirements for the actual project. Requirements in another municipality may differ. The proposal should identify the parties responsible for design, approvals and construction.
Safety planning must address the work and site conditions. Ask how the contractor will manage access, fall protection, material handling and protection of occupants, and request the relevant documentation.
Confirm responsibilities before work starts
Confirm which requirements apply to the building and the proposed work. Product and warranty requirements depend on the selected assembly and written project terms.
Record who is responsible for design, approvals, inspections and any warranty registration in the proposal.
Choose a contractor for the building and proposed assembly
Evaluate a contractor against the building and proposed assembly, not a generic label. Ask for comparable commercial work, the named installation team and a scope that explains investigation, preparation, drainage, details and closeout.
Contractor evaluation criteria:
- Comparable projects with similar roof assembly and operating constraints
- Current WorkSafeBC clearance and insurance documents
- Installer approval required for the proposed written warranty, where applicable
- References relevant to the proposed work
- Clear scope, schedule, allowances and exclusions
- Written process for changes, inspections and closeout
Request the safety and site plans that apply to this project. Confirm roof access, fall protection, material handling, work below the roof and communication with occupants.
Compare proposals line by line. A professional scope identifies responsibilities and unresolved assumptions instead of relying on broad promises.
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Commercial roof installation FAQs
Move from planning to a building-specific proposal
For a building-specific scope, ask Paragon Roofing BC to review the roof condition, access and operating requirements. Bring any available roof drawings, leak records, previous repair information and the date you need the work planned around.
This guide supports project planning. The proposed roof assembly, scope, schedule, price and warranty terms must be confirmed for the building before work is agreed.
Use the enquiry form below to describe the property, the current roof concern and the timing you need to plan around.
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Plan your commercial roofing project
For roofing enquiries, contact Paragon Roofing BC at 604-358-3436.
Share the building location, roof concerns, available records and preferred timing. The full enquiry form follows.
