You never pay the reset twice
Removing and reinstalling an array to replace a membrane underneath it is pure cost with zero added generation.
Solution
Solar roofing and reroof coordination
The array will outlive the membrane underneath it. If the roof has under eight years left, doing solar first means paying twice: once to remove it and once to put it back.
- Typical range
- Any roof carrying a planned array
- Built for
- Buildings with 15+ year membranes and under 10 years left
Overview
What this actually involves
A commercial single-ply membrane has a service life. A solar array has a 25-year production warranty. If those two numbers do not line up, the building owner absorbs a remove-and-reset cost somewhere in the middle, and it is never budgeted.
So we survey the roof properly before the array is designed. Core samples where warranted, a moisture scan of the insulation, seam and flashing inspection, drain and ponding assessment, and a written remaining-life estimate with the manufacturer's warranty status attached.
Where the roof needs replacing, the sequence is simple and the savings are real: reroof, then install. One mobilisation, one crane, one set of safety rails, and the array lands on a membrane with its full warranty ahead of it. Doing it in that order typically costs far less than doing it in the wrong order and paying the reset.
We work with the membrane manufacturer throughout so the roof warranty is continued rather than quietly voided. That documentation matters when a leak shows up in year seven and two contractors are pointing at each other.
Scope of supply
What is included
- Roof condition assessment: membrane type, age, seams, flashings, drains, ponding and penetrations
- Infrared or capacitance moisture survey to find saturated insulation before it is built over
- Core sample where the assembly is unknown, with the deck and insulation build-up documented
- Written remaining service life estimate and a warranty status check with the manufacturer
- Reroof specification and scope coordinated with the array layout so ballast and attachment land correctly
- Combined schedule: one mobilisation, one set of roof protection, one crane pick where possible
- Manufacturer-approved attachment or ballast details, submitted for warranty continuation
- As-built roof plan showing every array component relative to drains, seams and equipment
Sequence
How it runs
- 01
Assessment
Walk the roof, scan for moisture, core where needed, and write down what is actually up there.
- 02
Decision
Reroof first, install now, or a partial overlay on the array footprint only. The membrane's remaining life decides.
- 03
Coordinated specification
Roofing scope and array layout drawn together so nothing lands on a seam or blocks a drain.
- 04
Sequenced build
Membrane goes down, slip sheets and pads go in, racking follows, all inside one site set-up.
- 05
Warranty package
Roofing manufacturer documentation, array as-builts and the combined maintenance schedule, handed over as one file.
Why it works
What you get out of it
One mobilisation, not two
Shared crane time, shared safety set-up and shared site access take real money out of the combined job.
The roof warranty survives
Manufacturer-approved details, submitted and documented, so you still have a warranty in year nine.
Moisture gets found early
Wet insulation discovered before the array goes on is a repair. Discovered afterwards it is a demolition.
What moves the price
Cost and schedule drivers
| Factor | Effect on the project |
|---|---|
| Remaining membrane life | Under 8 years strongly favours reroof-first; over 15 years usually means install now |
| Existing warranty terms | Some warranties require manufacturer approval and specific details before anything is attached or ballasted |
| Insulation moisture | Saturated areas must be cut out and replaced, which is discovered work and needs a contingency |
| Deck type and condition | Corroded steel deck or a rotted nailer changes both the reroof and the attachment strategy |
| Drainage and ponding | Ponded areas need slope correction before racking, or you build a problem into a 25-year asset |
Often paired with
Related solutions
Answers
Solar roofing and reroof coordination: common questions
Not covered here? Our engineers answer directly, not through a call centre.
Ask a question(661) 555-0183Membrane type and age set the baseline, then condition adjusts it: seam integrity, flashing condition, ponding, UV degradation and moisture in the insulation. We write the estimate down with the evidence behind it rather than offering an opinion on site.
Sometimes, and it can be a sensible compromise on a large roof with a small array footprint. It does create a transition detail and a mixed-age roof, so we only recommend it when the geometry is clean.
The membrane manufacturer holds the roof warranty, continued through their approved detail and documented submittal. We hold the workmanship warranty on the array and its attachments. You get both in writing.
It adds time to the front of the programme, typically a few weeks on a mid-size roof. Since the interconnection application is running in parallel, it often costs less calendar time than it appears to.
Bring us the bill before you bring us the roof
Every project starts with twelve months of interval data and a load shape. The array comes after that, sized to what you actually use.
CSLB #1071482 (sample). Prevailing wage on public works. Engineers answer, not a call centre.