Plan a new roof installation around the complete roof assembly, site conditions and a clear written scope.
Start with the roof design
A new roof on an addition or new building must suit its structure, slope and drainage. The covering is only one part of the system. Ask how the installer plans the deck, underlayment, flashing, ventilation, edges and transitions. A roof that looks straightforward from the street may have details around walls, valleys or equipment that need special attention.
Compare a complete specification
Ask each professional to name the proposed product, installation method and components in writing. Confirm how the work will follow manufacturer instructions and current local requirements. The proposal should say who obtains permits, how inspections are scheduled and what happens if construction drawings or site conditions change.
- Which roof areas and slopes are included?
- How will the assembly manage water at edges and penetrations?
- Are flashing, ventilation and cleanup in the price?
- What documentation is provided at completion?
Coordinate the job with other work
On a new build or addition, roof installation may depend on framing, decking, masonry, siding and mechanical work. Ask who coordinates penetrations and who is responsible for final weatherproofing at each trade interface. Agree on a process for changes before work starts, especially if the roof design or materials are still being finalized.
Review the completed installation
Keep the product information, warranty terms, final invoice and permit records together. Ask for a walkthrough of critical details and a plan for reporting a concern after the crew leaves. A clear handoff helps distinguish normal upkeep from an installation question later.
How the scope can change
A new addition meets an existing roof at a wall and valley. The visible covering may match, yet drainage and flashing at the junction can make or break the result. Ask for drawings or a clear written detail showing how the new underlayment, edges and covering connect to the old assembly. Also clarify which trade completes each roof penetration and who checks the weatherproofing afterward.
Evidence to compare before choosing work
| If the assessment finds | What to discuss |
|---|---|
| The new roof ties into an existing roof | Focus on transitions, material compatibility and responsibility at the interface. |
| The project changes roof pitch or framing | Confirm structural design and a permit route before selecting covering. |
| The house has a low-slope portion | Choose an assembly suited to its drainage and access rather than default shingles. |
What to get in the written proposal
Ask for enough detail to compare the physical work and understand what could change after materials are opened.
- Roof plan, slope and structural assumptions for each new area.
- Exact covering, underlayment, flashing, edge and ventilation components.
- Trade coordination at walls, vents, skylights and other penetrations.
- Permit, inspection, schedule, change-order and completion-document responsibilities.
Before and after the work
Ask for a pre-covering photo record at critical transitions and keep the product specification with approved plans. At completion, review drainage paths and roof openings with the installer. If an addition is part of a larger construction job, make sure the roofing handoff explains who handles later siding or mechanical work that touches the roof.
Common questions
Is roof installation the same as replacement?
Installation can be part of a new build or addition. Replacement also includes removing or covering an existing system and handling its condition.
Can I choose material only by appearance?
Appearance matters, but slope, structure, drainage, climate and product requirements also affect suitability.
What should be included in a bid?
Ask for product names, complete components, labor, permits, disposal where needed, schedule, payment stages and written terms.
Sources and further reading
These resources can help you verify general guidance or current local requirements for your property.