Product Identification Testing for Siding Claims

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Before anyone can determine whether replacement siding will match existing siding, someone first has to determine exactly what the existing siding is. That identification step sounds simple and often is not, particularly on a home that has changed hands once or twice since the siding was installed and where no records survive describing the original product.

Manufacturers commonly emboss identifying marks on the back or the locking edge of vinyl siding panels, including a product code, color designation, and sometimes a manufacturing date or plant code. When accessible, usually by removing a single panel from an inconspicuous area, this embossed information can identify the product line directly, allowing a straightforward comparison against the manufacturer’s current catalog to determine whether the exact product remains available or has been discontinued. This is the most reliable identification method when the marking is legible and the manufacturer maintains accessible historical records for that product line.

When embossed markings are absent, illegible, or belong to a manufacturer no longer in business, evaluators often turn to profile comparison, matching the panel’s exposed width, lock design, and surface texture against known manufacturer profiles using reference catalogs or databases maintained by industry organizations and testing laboratories. Profile matching can narrow the field of likely manufacturers even without a legible mark, though it typically cannot pinpoint an exact discontinued color with the same confidence as a direct embossed identifier.

Color identification adds a further layer of testing beyond simple visual comparison. A spectrophotometer measures the precise wavelength characteristics of a surface’s color, producing a numeric value that can be compared against a manufacturer’s color specifications or against a sample of new material, accounting for the oxidation and fading that naturally affects older siding. This instrument-based approach reduces the subjectivity involved in deciding whether two materials constitute a visual match, though it still requires interpretation, since a policy’s own matching standard, not the spectrophotometer reading alone, ultimately determines whether a given color variance matters.

It is worth being clear about what this testing does and does not resolve. Identifying the product, determining whether it remains in production, and quantifying any color difference are factual exercises that an appraiser, contractor, or testing laboratory can perform and document. Whether a given degree of variance obligates a carrier to replace additional undamaged siding is a separate question governed by the policy’s specific language and any applicable state standard, and that determination belongs to the parties, their appraisers, or the courts, not to the identification testing itself.

This type of identification testing is usually commissioned by whichever party needs a defensible factual record, which in practice can be an appraiser working through a matching dispute, a contractor preparing a repair proposal, or an attorney building a record for later review. Access to the siding itself is often the limiting factor rather than the availability of testing methods, since a homeowner or contractor generally needs to remove at least one panel to expose an embossed marking or obtain a usable sample for spectrophotometer comparison, and that removal should be done carefully to avoid creating additional damage that then has to be accounted for separately in the claim.

This article is provided as general education on the appraisal process. It is not legal advice, and procedures vary by state and by policy.

Based in Minnesota and serving clients nationwide, Russ Lis is a working property insurance appraiser and umpire. Contact Appraisal Resolution.