Does a contractor’s scope of work always align with manufacturer specifications?
Understanding the Gap Between Quotes and Compliance
In commercial roofing, there is often a significant disconnect between a contractor’s proposal and the manufacturer’s technical requirements for warranty issuance. A common misconception among facility managers is that if a contractor specifies a certain brand of membrane, they are automatically including every component and method required by that manufacturer.
However, manufacturer specifications are often rigorous and include specific requirements for fasteners, adhesives, flashing details, and insulation densities. Because these components increase material and labor costs, they may be excluded from a competitive bid to keep the price lower. If these elements are missing, the manufacturer may refuse to issue the warranty upon final inspection, leaving the asset owner with an unbacked system.
Why the Discrepancy Occurs
- Standard vs. Enhanced Wind Uplift: Manufacturers have different attachment patterns based on building height and geographic location. A standard quote may not account for the specific wind-uplift requirements of your asset.
- Accessory Substitutions: Contractors may use third-party adhesives, boots, or termination bars that are not approved for use within a total-system warranty.
- Ambiguous Language: Phrases such as "installed per industry standards" are not the same as "installed per manufacturer's written specifications for a 20-year NDL warranty."
How to Verify Alignment
Before signing a contract, request the manufacturer’s "Specification Plate" or the specific system code (e.g., an Assembly Number from UL or FM Global) that the contractor intends to follow. Compare the line items in the contractor’s scope of work against the requirements listed in the manufacturer’s technical manual for that specific system code.
If the proposal lacks detail on fastener frequency, insulation type, or specific flashing membranes, the risk of a warranty rejection at the end of the project increases significantly.
Key Takeaways
- Brand mention is not compliance: Simply naming a manufacturer in a quote does not obligate the contractor to follow every warranty-critical step unless specified.
- Omissions reduce price but increase risk: Lower bids often achieve their price point by excluding manufacturer-mandated accessories.
- Demand specificity: Ensure the contract explicitly states that the installation will meet all requirements for the specific duration and type of warranty requested.
Next step
Verify that your contractor's written scope of work explicitly matches the manufacturer's required assembly components for the intended warranty.