This is a checklist for the weeks before a commercial roof replacement. It covers what has to be known, decided, budgeted and agreed before the first area is opened.
Work through it before the quotes go out. Most of it shapes what you are asking for.
The evidence
| Settle | Why it matters |
|---|---|
| Current condition report | The scope rests on it, and so does the decision to replace at all |
| Moisture survey | Decides recover against tear off, and nothing else does |
| Deck type and condition where visible | Drives the largest unknown in the budget |
| Existing build up | System, insulation, attachment, number of existing layers |
| Repair and leak history | Shows whether the failures are general or concentrated |
| Roof plan with areas numbered | Lets the scope be phased rather than quoted as one block |
The decisions
| Decide | What depends on it |
|---|---|
| Recover or tear off | The largest single cost difference between two quotes |
| System and manufacturer | Warranty, approved installers, detail availability |
| Insulation type and thickness | Code compliance, energy performance, detail heights |
| Attachment method | Wind uplift performance and deck suitability |
| Drainage changes | Whether existing falls and outlets are being corrected |
| Phasing | Whether the roof is done in one project or in areas |
| Surfacing or coating | Reflectivity, traffic protection, later maintenance |
The budget
| Include | Why it is missed |
|---|---|
| Tear off and disposal | Omitted whenever a recover is assumed |
| Deck repair rate | Unknown until the roof is open, so it is left out |
| Code driven upgrades | Insulation values move, and the existing roof predates them |
| Equipment removal and reinstatement | A different trade, so it falls between scopes |
| Craneage and access | Priced only when somebody visits the site |
| Temporary protection | Needed in occupied buildings and rarely allowed for |
| Design and inspection fees | Small, predictable, and forgotten every time |
| Contingency | The deck is the reason it exists |
The logistics
| Agree | What to watch for |
|---|---|
| Start and completion dates | With the weather assumptions behind them stated |
| Nightly watertight plan | How an open roof is secured at the end of each day |
| Storm response | Named contacts and a response time, in writing |
| Working hours | Occupied buildings and hot weather both constrain them |
| Crane and lay down areas | Which parts of the site stop working, and when |
| Air intakes | Identified before any hot or odorous work begins |
| Tenant notice | Dates, hours, expected noise, and a named contact |
The paperwork
| Confirm | Why |
|---|---|
| Written scope | The only thing that makes two quotes comparable |
| Contractor license and insurance | Verified directly, not through a forwarded document |
| Manufacturer approval | Confirmed with the manufacturer for this system |
| Permit responsibility | Who applies, who pays, who schedules inspection |
| Payment schedule and retention | Proportionate to work completed |
| Lien waivers | Provided as payments are made |
| Warranty specimen | The conditions, not only the certificate |
What to do with it
- Survey before you quote. The survey decides the scope, and the scope decides the price.
- Write one scope and send it to everybody. Three quotes against three scopes is not a comparison.
- Get a deck repair rate from every bidder. This is where the surprise lives.
- Agree the weather plan in writing. An open roof is the most exposed the building will ever be.
- Tell the tenants two weeks out. Most complaints are about surprise, not disruption.
Want the reasoning behind these checks? Read how replacement works and recover against tear off.
Walked by Date Roof
Common questions
How do you know a roof is ready to be replaced rather than repaired?
When repairs stop holding, when the failures spread rather than repeat in one place, or when a survey finds wet insulation across a meaningful area. Age on its own is not the test, and neither is a single bad winter, because a well maintained roof can outlive its nominal service life by years.
- Repairs that fail within a season rather than lasting
- Failures appearing in new places rather than recurring in one
- Wet insulation confirmed across a measurable area
- Deck corrosion or rot found during a repair
- Repair spend approaching a meaningful fraction of replacement each year
The honest version of this decision needs a number on both sides. Annual repair spend against the amortized cost of replacement, with the risk to the contents of the building added to the repair side. Most buildings cross that line two or three years before anybody writes it down, and the gap between crossing it and acting on it is where most of the avoidable cost sits.
Recover or tear off?
Recover is cheaper and faster where the existing build up is dry and sound, the deck is in good order and the code and the structure both allow another layer. Tear off is the answer everywhere else, and the test is a survey rather than a preference or a budget.
- Wet insulation rules out a recover entirely
- Most codes limit how many layers a roof may carry
- Structural capacity has to allow for the additional weight
- A recover hides the deck, which is sometimes the point and sometimes the problem
- Existing drainage and detail heights constrain what a recover can achieve
Get the survey before the quotes, not after them, because the answer changes the scope and therefore every price you are about to receive. A recover quoted against a roof that turns out to need stripping is not a saving, it is a variation waiting to happen, and it will arrive at the point in the project when you have least room to respond to it.
What is the commonest budget surprise?
The deck. Nobody knows what is under the insulation until the roof is open, and a deck that has been wet for years can need patching, plating or wholesale replacement across areas nobody anticipated. It is also the one item that cannot be surveyed away in advance.
- Deck condition is unknown until the roof is stripped
- Corroded metal deck and rotted timber both need replacing, not coating
- Code driven insulation upgrades can add materially to a like for like price
- Equipment removal and reinstatement is often a separate trade
- Disposal costs rise sharply with certain older materials
Ask every bidder for a stated rate for deck repair per unit area, and build a contingency around it rather than hoping. A named rate turns the unknown into arithmetic you can do on the day the roof is opened, and it removes the single commonest source of mid project argument between an owner and a roofer.
What has to be agreed before work starts?
The scope in writing, the payment schedule, the change order process, the plan for making the roof watertight each night, and what happens to the building if weather arrives while the roof is open. All five are cheap to agree in advance and expensive to settle afterwards.
- A written scope naming the system, build up and detail treatment
- A payment schedule proportionate to work completed
- How a variation is priced and who may authorize it
- Nightly tie offs and temporary waterproofing
- Who carries the risk of water entering during the works
The phase of the project where the building is most vulnerable is the phase where nobody has agreed anything in writing, because it begins the moment the first area is opened. A contractor who has a clear, practiced answer to the weather question has done this work before on occupied buildings, and that is worth more than a small difference in price.
What about the tenants and the operation below?
They need to know what is happening, when, and what it will sound and smell like. Roof replacement is noisy, it can be disruptive to anyone directly beneath it, and some systems involve odors that will find their way into a building through its air intakes.
- Notice to tenants with dates, hours and expected disruption
- Air intake locations identified before any hot or odorous work
- Protection for equipment, stock and finishes beneath open areas
- Agreed working hours, particularly where the building is occupied
- A route for deliveries and craneage that does not block the operation
Most tenant complaints during a roof replacement come from surprise rather than from the disruption itself, which people accept readily when they have been told what to expect. A single letter two weeks ahead, naming dates and a contact, prevents the majority of them and costs an afternoon of somebody's time. Name one person as the point of contact for the duration and put their number in the letter, because a complaint that reaches the right person on the first attempt rarely becomes a dispute.