Commercial Roof Warranties: NDL vs Manufacturer vs Contractor Warranties
The Three Kinds of Commercial Roof Warranty
| NDL system guarantee | Material-only warranty | Contractor warranty | |
|---|---|---|---|
| Who stands behind it | The manufacturer | The manufacturer | The installing contractor |
| What it covers | Leaks from covered causes in the manufacturer's listed roof system, typically including installation workmanship on those materials | Manufacturing defects in the membrane | The contractor's workmanship, as written in the contract |
| Dollar cap | None on covered repairs | Often capped per roofing square | Set by the contract |
| Typical requirements | Approved contractor, manufacturer inspection, fee, maintenance records | Proof of purchase, timely notice, maintenance | Depends on the contractor |
The examples below come from manufacturers' published specimen forms. Issued warranties can differ, so always read the document for your own roof.
What an NDL Guarantee Covers
GAF's EverGuard (TPO) Diamond Pledge NDL Roof Guarantee form says GAF will repair leaks through its listed roofing materials "resulting from a manufacturing defect, ordinary wear and tear, or workmanship in applying the GAF Roofing Materials. There is no dollar limit on covered repairs." Johns Manville's Peak Advantage Guarantee sample lists the maximum obligation as "No Dollar Limit" and covers leaks from ordinary wear and tear, defects in JM components, or "workmanship deficiencies only to the extent they arise solely out of the application of the Roofing System."
Three limits are built into both:
- Only the manufacturer's system. GAF: "Leaks caused by any non-GAF materials, such as the roof deck or non-GAF insulation, are not covered." JM: "ALL OTHER NON-JM COMPONENTS OF THE OWNER'S BUILDING ARE EXCLUDED."
- Leaks, not everything. GAF's form says it does "NOT cover conditions other than leaks," and that GAF is not liable for "CONSEQUENTIAL OR INCIDENTAL DAMAGES of any kind, including, but not limited to, interior or exterior damages and/or mold growth." JM's sample says it "is not a maintenance agreement or an insurance policy."
- Weather limits. Both specimen forms exclude winds over 55 miles per hour. GAF's form with hail coverage covers hail punctures only up to a diameter written into the document, and then only the punctured membrane.
Manufacturers also inspect before issuing system warranties. Carlisle states that "all warranted roofs are thoroughly inspected by a field service representative," and JM says it makes a final inspection on each guaranteed roofing system on completion.
Material-Only Warranties
A material warranty is narrower. Johns Manville's Limited Labor and Material Warranty sample covers a membrane that is "free from manufacturing defects which could cause a leak" and that will not deteriorate from weathering to the point that it cannot stay watertight. It caps the total at $150 per roofing square: the form sets "maximum liability over the term of this limited warranty" at "$150.00 inclusive of both labor and material for each installed roofing square (100 SF) of membrane" (capitalized in the original). A leak caused by an installation mistake is not a membrane defect, so a material warranty may not respond to it at all.
Contractor Workmanship Warranties
A contractor warranty is the installer's promise to fix problems caused by its own work. Its length, what it covers and how claims are handled are whatever the contract says, so get it in writing. The two warranties work side by side: manufacturer forms make clear that the contractor does not speak for the manufacturer. GAF's form states, "The roofing contractor is NOT an agent of GAF; notice to the roofing contractor is NOT notice to GAF." JM's says "roofing contractors are not agents of JM."
In practice, that means a leak on a roof with both warranties should be reported to both, in the way each document requires.
The Fine Print Owners Miss
- Notice deadlines. GAF's form requires written notice to GAF "within 30 days" of a leak; JM's material warranty says claims are waived unless received within 30 days of discovery.
- Maintenance records. GAF: "You must perform regular inspections and maintenance and keep records of this work." Repairs needed to keep coverage "must be performed by a GAF-certified roofing contractor."
- Changes to the roof. New equipment, penetrations, solar or other additions without the manufacturer's written approval can fall outside coverage.
- Foot traffic and chemicals. GAF excludes traffic except on approved walkways, and "chemical attack on the membrane, including, but not limited to, exposure to grease or oil."
- Drainage. JM's NDL sample excludes leaks resulting from "improper drainage." Some other forms exclude ponding. See ponding water on a flat roof.
- Payment and transfer. GAF's guarantee takes effect only after installation and supply bills are paid. Transferring it to a buyer requires a written request within 60 days of the sale, any required repairs and a fee.
Questions to Ask Before You Sign
- Which warranty is included: NDL system, material-only, or contractor only? Ask for a specimen copy.
- What term, wind speed and hail size does it cover?
- Is the contractor approved by that manufacturer to obtain this warranty, and is the warranty fee in the price?
- What maintenance must the owner do, and who keeps the records?
- What is the contractor's own workmanship warranty, in writing?
- Can the warranty be transferred if the building is sold?
Driftwood is a GAF Master Elite contractor. For a specific building, our commercial roofing team can walk you through the warranty options for the proposed system and what each one would require of you as the owner.
Sources: GAF EverGuard Diamond Pledge NDL Roof Guarantee, Hail Coverage, specimen form COMTS728-1224; Johns Manville Peak Advantage Guarantee sample and Limited Labor and Material Warranty sample (RS-2357); Carlisle SynTec Warranty Services page; Johns Manville Guarantee, Technical and Warranty Services page. Specimen terms only; your issued warranty controls.
Frequently Asked Questions
What does NDL mean on a roof warranty?
NDL stands for no dollar limit. On an NDL roof guarantee, the manufacturer pays for covered leak repairs without a cap on the total cost, subject to the warranty terms and exclusions.
Does an NDL warranty cover workmanship?
The specimen NDL forms we reviewed do, for workmanship in installing the manufacturer's own materials. GAF's and Johns Manville's specimen NDL forms both include installation workmanship on their listed roof system, but not non-manufacturer components such as the deck.
What is the difference between a manufacturer warranty and a contractor warranty?
A manufacturer warranty is the product maker's promise about its materials or roof system. A contractor warranty is the installer's promise about its own work, with terms set by the contract. Report leaks to both, as each document requires.
Does an NDL warranty cover hail damage?
Only as written. Standard forms exclude hail above a stated size, and some hail-coverage forms repair only the punctured membrane. Check the hail size and coverage language on your own guarantee.
What can void a commercial roof warranty?
Common examples in specimen forms include late leak notice, missing maintenance records, unapproved changes or equipment on the roof, foot traffic outside walkways, chemical or grease exposure, and unpaid installation bills.
