01Profile the interior and roof-space conditions
Record building use, conditioned rooms below the roof, attic or compact-roof form, interior humidity concerns, insulation history and mechanical exhaust routes. Note whether bathroom, kitchen or dryer ducts terminate correctly without entering the attic. Different roof areas may have different cavities or renovations. This profile does not diagnose condensation, but it gives the project team context to distinguish exterior water entry from indoor moisture movement and cold-surface conditions.
- Map conditioned-space boundaries
- List exhaust routes
- Separate additions and original construction
02Separate leaks, condensation and construction moisture
Document when and where staining, dripping, frost, odour or damp materials appear. Relate observations to weather, occupancy and mechanical use without declaring a cause from photographs. A roof leak, air leakage, vapour diffusion, blocked ventilation or wet materials can produce overlapping symptoms. Ask what evidence is needed to diagnose the condition and which party is responsible for building-envelope, mechanical or roofing review before the new assembly is finalized.
- Use dates and weather context
- Do not label a cause remotely
- Assign investigation responsibility
03Verify the deck and substrate
Identify the proposed deck or support for the metal system and how existing condition will be checked. Record sheathing type and thickness only when supported by records or safe investigation. Ask how damaged, uneven or wet areas are handled, which tolerances apply and how fastening reaches verified support. Deck preparation should connect to the panel manufacturer’s current requirements and project-specific design, not a generic statement that the surface will be made ready.
- Separate observed and assumed substrate
- Define replacement pricing
- Verify fastening support
04Specify underlayment by zone and function
List field underlayment, eave or valley membranes, separation layers and transition products by exact name and location. Compare substrate preparation, primer, temperature, exposure-time, fastening and lap requirements in current documents. Show how materials meet at eaves, valleys, walls, curbs and penetrations. Underlayment should not be described as a universal cure for an unresolved assembly, and substitutions should reopen compatibility review before installation.
- Create an underlayment map
- Keep current product data
- Approve substitutions in writing
05Draw ventilation as a continuous route
Document intake and exhaust locations, roof cavities, baffles, blocked paths and interactions with insulation or mechanical ducts. Ask for the basis used to size openings and the method of preserving the route at valleys, hips, short rafter bays or additions. Counting vents is not the same as demonstrating connected airflow. If the design uses another moisture-control strategy, require it to be shown in the complete roof section and reviewed for the building.
- Connect intake to exhaust
- Show obstructions
- Photograph concealed ventilation work
06Coordinate metal details with hidden layers
Follow the deck and underlayment through eaves, rakes, ridges, valleys, walls, gutters, skylights, chimneys and curbs. Identify where fasteners penetrate, where water is redirected and where movement is accommodated. Confirm compatibility with sealants, treated wood, dissimilar metals and rooftop equipment. The visible flashing should be traceable to the concealed water-control layer so an attractive edge does not mask a discontinuity underneath.
- Use numbered details
- Assign interfaces
- Record concealed transitions before covering
07Create a hidden-assembly closeout package
Issue one roof-section schedule connecting interior moisture context, air and vapour assumptions, insulation, ventilation cavity, deck, underlayment zones and metal covering. Cross-reference accepted products and details, then add inspection notes and photographs before concealment. Record changes in geometry, material or ventilation and identify who reviewed them. The package supports future diagnosis and maintenance, but it cannot guarantee condensation control or establish the cause of a pre-existing moisture problem.
- Archive product revisions
- Index photos by roof area
- Keep unresolved observations visible