Typical scope
- Core cuts and moisture survey before the scope is written
- Full tear-off to deck, including disposal and deck repair
- Re-cover over an existing single layer where code and condition allow
- New insulation to the required R-value, with tapered board to correct drainage
- Complete detail rebuild at curbs, drains, scuppers and parapets
- Manufacturer system warranty through an approved applicator
Tear-off or re-cover
A re-cover installs a new system over the existing roof. It is cheaper and faster because there is no demolition and no disposal, and it exposes the building to weather far less. It is only appropriate when the existing insulation is dry, the deck is sound, and the number of existing layers permits another. Building codes generally limit a roof to two layers; a third means everything comes off.
A tear-off removes everything down to the deck. It costs more and takes longer, but it is the only honest option when insulation is saturated, when the deck needs repair, or when there are already two roofs up there. It is also the opportunity to correct slope properly with tapered insulation rather than working around the existing problem.
Core cuts settle the argument
A core cut is a small square removed through the whole assembly and then patched. It shows exactly how many layers exist, what they are, whether the insulation is wet and what condition the deck is in. It costs very little and it converts a guess into a specification. Any replacement quote written without core cuts or a moisture survey is an estimate with change orders built into its future.
What belongs on the quote
Membrane type and mil thickness. Attachment method, mechanically attached, fully adhered or ballasted. Insulation type, thickness and R-value. Whether tapered insulation is included and where. How each curb, drain, scupper and parapet will be flashed. Tear-off versus re-cover, and disposal. The workmanship warranty from the contractor and the system warranty from the manufacturer, which are separate documents with separate exclusions. Two quotes on the same roof can differ by half simply because one includes tapered insulation and the other does not.
Permits and Title 24
Replacement in California requires a permit, and the permit triggers a Title 24 energy compliance check, normally a CRRC-rated cool-roof surface on a low-slope roof, and depending on scope, added insulation. Settle this at permit stage, because insulation thickness affects edge metal heights, drain extensions and door thresholds.