When a building owner says “we have a twenty-year warranty,” there are at least three different documents that sentence could be describing, and they protect you from very different things.
Knowing which one you hold matters most on the day you need it. Here is what each warranty is, what voids it, and what to ask before you sign anything.
The three warranties, and why people confuse them
1. The manufacturer material warranty
This covers the membrane itself against manufacturing defects. If the sheet delaminates, blisters from a formulation problem, or otherwise fails because of how it was made, the manufacturer replaces the material.
What it does not cover is labor. If a defective sheet needs to come off and go back on, the material shows up free and you pay for the crew, the tear-off, the disposal, and everything else.
Material warranties are often what gets handed over on smaller projects. They are real coverage and they are the narrowest of the three.
2. The manufacturer system warranty, including NDL
A system warranty covers the assembly, not just the sheet. Membrane, insulation, fasteners, adhesives, and flashings, as long as every component came from the approved list and the installation followed the manufacturer’s published details.
NDL stands for “no dollar limit.” On an NDL warranty, the manufacturer’s obligation to repair covered leaks is not capped at the original material cost. On a limited system warranty, it often is, which means a large failure late in the term can exhaust the coverage and leave you funding the rest.
System warranties require three things that material warranties do not: an approved contractor, an approved full-system specification, and a post-installation inspection by the manufacturer before the warranty is issued. That inspection is the real quality control on the project, and it is one of the strongest arguments for specifying a system warranty on any roof you intend to keep.
3. The contractor workmanship warranty
This covers installation. Seams that were not welded properly, flashings that were not terminated correctly, fasteners in the wrong pattern, details that do not match the drawings.
Workmanship warranty terms vary widely, commonly from two to ten years depending on the contractor and the project. It is the warranty that covers the most common real-world cause of leaks on a new roof, and it is only worth the paper if the contractor is still in business when you need it.
Note the overlap: on an NDL system warranty, the manufacturer typically covers workmanship as well for the term, because the manufacturer inspected and approved the installation. That overlap is a large part of what the NDL premium buys.
Side-by-side
| Material warranty | System / NDL warranty | Workmanship warranty | |
|---|---|---|---|
| Who issues it | Manufacturer | Manufacturer | Contractor |
| Covers material defects | Yes | Yes | No |
| Covers labor to fix | No | Yes | Yes |
| Covers installation errors | No | Yes, for the term | Yes |
| Covers flashings and accessories | No | Yes, if approved components | Yes, as installed |
| Requires approved contractor | No | Yes | N/A |
| Requires manufacturer inspection | No | Yes | No |
| Typical term | 10 to 30 years | 10 to 30 years | 2 to 10 years |
| Transferable on sale | Sometimes | Usually, with conditions | Rarely |
What voids each one
Warranties are denied more often for maintenance and modification issues than for anything the roofer did.
Unauthorized work on the roof. The single most common denial. Another trade cuts the membrane to run conduit, patches it with the wrong material, and the manufacturer rightly says the assembly was modified. Every penetration added after installation needs to be flashed to the manufacturer’s detail by an approved contractor.
New equipment set without proper flashing. A new rooftop unit, satellite dish, solar array, or antenna bolted through the membrane voids coverage in that area and sometimes beyond it.
Standing water. Most manufacturer warranties exclude damage from ponding water that remains beyond a specified period after rainfall. If the roof does not drain, the coverage narrows.
Grease, chemical, or petroleum exposure. Covered only if the membrane was specified for it. Putting a kitchen exhaust fan over a membrane that was not selected for grease and then claiming membrane failure does not work.
Missing maintenance documentation. Most system warranties require periodic inspections and basic upkeep, with records. No records, no claim.
Failure to report leaks promptly. Warranties carry notice periods, often measured in days. A leak you lived with for two years and then reported is a maintenance failure in the manufacturer’s eyes.
Structural movement, deck failure, and acts outside the roof system. Foundation settling, deck deflection, and damage originating below the roof are excluded. So, usually, are hail and wind above a stated threshold, which is an insurance matter rather than a warranty matter.
Required maintenance documentation
Treat this as a filing obligation from the day the roof goes on.
Keep, for each roof:
- The warranty certificate itself, with the warranty number and the exact term
- Inspection reports, typically twice yearly, from a qualified contractor
- A repair log with dates, locations, descriptions, and who performed the work
- Photographs of conditions found and work completed
- Drain cleaning records
- Documentation of every rooftop change, including new equipment and new penetrations, with proof the flashing work was done to the manufacturer’s specification
When a claim gets filed, the manufacturer asks for this file. The owners who have it get paid and the owners who do not spend months arguing.
Transferability when the building sells
Most manufacturer system warranties are transferable, and almost all of them have conditions:
- A limited window. Transfer requests usually must be made within a set number of days after the sale closes.
- A transfer fee. Modest, but real, and someone has to remember to pay it.
- An inspection. The manufacturer frequently requires an inspection before transfer and will list required repairs that have to be completed at the seller’s or buyer’s cost before the warranty moves.
- A one-time limit. Many warranties allow exactly one transfer over the life of the term.
Contractor workmanship warranties are usually not transferable unless the document says so.
If you are buying a building, ask for the warranty certificate during due diligence, not after closing. If you are selling, a clean warranty transfer with a recent inspection report is a genuine asset at the table.
Questions to ask before you sign
- Is this a material warranty, a system warranty, or NDL? Ask for the actual document, not the brochure.
- If it is a system warranty, is there a dollar cap, and what is it?
- What wind speed is covered, and is there a wind rider available?
- What is the workmanship warranty term, in writing, separate from the manufacturer document?
- Who responds first on a leak call, the contractor or the manufacturer, and how fast?
- What maintenance is required to keep the warranty valid, and who is performing it?
- What is the notice period for reporting a leak?
- Is the warranty transferable, how many times, and what does transfer require?
- Is every component in the assembly on the manufacturer’s approved list, including insulation, cover board, fasteners, and edge metal?
- Is the installing contractor currently approved by this manufacturer for this system at this warranty tier?
That last one is not a formality. Manufacturers only issue system warranties through contractors they have approved for the specific product line. We install systems from manufacturers including Carlisle, Johns Manville, FiberTite, Sika Sarnafil, Soprema, Siplast, GAF, and CertainTeed, which lets us match the warranty tier to how long you plan to hold the building rather than to whatever one product line we happen to stock.
Frequently asked questions
Does a roof warranty cover storm damage?
Generally no. Wind damage above the warranty’s rated speed, hail, falling trees, and similar events are insurance claims, not warranty claims. Some manufacturers offer wind riders that extend coverage to higher speeds for an added cost, which is worth pricing on exposed buildings. For damage that has already happened, storm damage restoration and the insurance process are the right path.
My tenant’s HVAC vendor worked on the roof. Did that void my warranty?
It can, in that area. Any penetration, curb modification, or membrane cut made by another trade needs proper flashing by an approved roofing contractor. The practical fix is a written rooftop access policy requiring your roofing contractor to be notified before any other trade goes up, and to perform or inspect any work that touches the membrane.
Is an NDL warranty worth the extra cost?
On a building you plan to hold for a long time, usually yes. The value is less about the dollar cap and more about what NDL requires: an approved contractor, a full approved system, and a manufacturer inspection before the warranty issues. On a building you expect to sell in a few years, a transferable system warranty may serve you better than the highest tier.
What happens to my warranty if my roofing contractor goes out of business?
The manufacturer system warranty stays in force, because it is the manufacturer’s obligation, and the manufacturer assigns another approved contractor to perform covered work. The contractor workmanship warranty goes away with the contractor. That asymmetry is one of the better reasons to carry a manufacturer system warranty on a significant roof.
Get the warranty that matches the building
Warranty tier is a design decision, not a line at the bottom of a proposal. We walk through holding period, building use, rooftop equipment, and risk tolerance before recommending one.
See our approach to commercial roofing, review how we plan a roof replacement, or look at warranty specification on new construction roofing projects. To talk through what is on your building now, contact Red Letter Roofing at (919) 977-5318.