Evaluation Reports and What They Prove

Why this matters

The code is written around materials it can name: dimensional lumber, specified nails, a masonry unit to a listed standard. A structural screw that replaces a through-bolt, a siding product that is not wood, or a foam that is not covered by a prescriptive table has no row in the code to point at. The evaluation report is how such a product gets into a code-compliant building. Shops treat the report number on the box as a permission slip. It is not one, and the gap between what the report actually proves and what the box implies is where failed inspections and unsupported decks come from.

What an evaluation report is

An evaluation report is a document issued by an accredited evaluation service stating that a specific product, used in a specified way, complies with specified sections of specified model codes. In US building work the two most often seen are issued by the evaluation arm of the International Code Council (ICC-ES, reports numbered ESR) and by IAPMO's evaluation service (IAPMO UES, reports numbered ER). Both are accredited to ISO/IEC 17065, the international standard for bodies that certify products.

The code hook is the alternative materials section: the building official may approve a material, design or method not specifically prescribed if it is at least the equivalent of what the code requires, and may require tests or research reports from approved sources to support that finding. That is R104.11 in the 2021 IRC and 104.11 in the 2021 IBC, as adopted by your jurisdiction; the 2024 editions moved the section, so check the numbering in yours. The report is the "research report from an approved source". It is evidence offered to the official, who then decides.

A report is built from the manufacturer's test data, evaluated against an acceptance criteria document (the evaluation service's published rules for what testing a product category must pass), plus a quality program: the manufacturer's plant is inspected, and the product must carry an identification that ties it to the report.

What a report proves

When it is current and you are inside it, a report establishes four things the inspector can rely on without re-testing:

• Identity. This product, from this report holder, made at a plant under the inspection program, marked in a stated way.
• Performance values for named properties. Allowable loads, fire classification, weather resistance, durability, whichever the report lists. Only those.
• Compliance with named code sections in named editions. A report lists the codes and editions it evaluated against, often three cycles at once.
• An installation method. Fastener spacing, substrate, edge distances, required accessories, given in the report's own text and tables.

That is a lot, and it is genuinely valuable. It turns a product the code cannot name into one whose compliance the official can check against a document instead of a test rig.

What a report does not prove

This is where the money is lost. Each of these is a real assumption made on real jobs.

It does not approve anything. The official approves. A report is the strongest kind of evidence an official commonly accepts for a non-prescriptive product, and most will accept a current, applicable report without argument, but the section that gives the report its force gives the decision to the official. A jurisdiction can decline a report, ask for more, or require a local supplement. Some reports carry a supplement written against one state's or one city's amended code, and some states run their own product approval system that a national report does not replace. See related: Product Approvals in High-Wind and Wildfire States.

It does not cover an edition it does not list. A report evaluated against the 2018, 2021 and 2024 IRC says nothing about the 2015 IRC, and a jurisdiction still on 2015 has to accept it on its own judgment. Read the edition on the permit first. See related: The Edition on the Permit, Not the Newest Edition.

It does not cover a use it does not name. A fastener evaluated for wood-to-wood connections is not evaluated for wood-to-steel, or for attaching to engineered rim board, unless the report says so. A siding product evaluated on wood-framed walls is not evaluated on steel studs. Silence in the report is not permission.

It does not cover outside its conditions of use. Every report ends with a numbered list of conditions: maximum spacing, minimum substrate thickness, exposure limits, where a design professional is required, which treated lumber the fastener coating suits. These are not advice. They are the terms on which the compliance finding was made, and a product used outside one of them is outside the report entirely, not slightly less compliant.

It does not cover a different product with the same name. Product lines change, coatings change, a "Pro" version appears beside the standard one. The report lists the products it covers by name, size and sometimes coating. If the box in your hand is not in that list, the report is not about it.

It does not outlive its date. Reports carry an issue date and a reissue or expiration date, commonly one or two years out, and are reissued, revised or withdrawn. A PDF from a sales sheet three years old may describe a report that has since been revised to cut allowable values, or withdrawn because the plant left the program.

It is not a safety listing. An evaluation report addresses building code properties: structure, fire, weather, durability. Electrical and many mechanical safety questions are answered by a listing from a testing laboratory. Some products need both; one does not stand in for the other. See related: Listed, Labeled and Approved: Three Words That Are Not the Same.

It does not overrule the code where the code speaks directly. A report helps the official approve something the code does not prescribe. Where the code has a mandatory requirement on the same question, the report works within it.

How the report relates to the instructions on the box

Most reports reference the manufacturer's published installation instructions and require that a copy be on the jobsite. Many reports also say, in plain words, that where the instructions and the report conflict, the report governs. That clause matters, because marketing literature drifts: a carton may show a fastener pattern looser than the report's table, or advertise a use the report never evaluated. The report is what was evaluated; the carton is what was printed. See related: When the Instructions and the Code Disagree.

Worked example: a ledger screw that was in, then out, of its report

A deck crew is attaching a new ledger to a house band joist with a structural screw that carries an evaluation report number on the box, instead of the half-inch through-bolts the prescriptive deck table assumes. The permit is under the 2021 IRC as adopted. The report (values illustrative) says:

• Evaluated under the 2024, 2021 and 2018 IRC and IBC.
• Ledger to band joist: 2x ledger to a minimum 2x nominal solid sawn band joist, lumber of a minimum specific gravity of 0.42 (which covers common southern pine and Douglas fir-larch, but not every species group).
• Spacing given in a table by joist span; for a 12 ft joist span, illustrative spacing of 12 in on center in a two-row staggered pattern.
• Condition of use: the ledger may not be installed over siding or sheathing thicker than 1 in, with spacers or flashing per the report's details.
• Condition of use: in preservative-treated lumber, the screw's coating is evaluated for a named range of treatment chemicals and retentions; other treatments are outside the report.
• Report reissue date eleven months before the job.

Inside the report. The permit edition (2021) is listed. The house band is a 2x10 solid sawn joist of southern pine, which meets the species and size condition. The deck's joist span is 12 ft, so the crew installs to the 12 in two-row pattern. The ledger is treated to a retention named in the report. The report is current. Everything the inspector needs is in one document, and the crew leaves a printed copy, with the relevant table marked, in the permit box.

Outside the report. The same crew's next deck, a month later, is on a newer house whose rim is engineered rim board, not solid sawn 2x lumber. The report is silent on rim board. It is not a less-capable connection; it is an unevaluated one, and the screw's spacing table is meaningless there. The crew's options are a fastener whose report names that rim board product type, the rim board maker's own published ledger detail, or an engineered connection. Using the first deck's spacing on the second house is the defect, and it looks identical from the yard.

What changed the answer. Not the screw, the deck or the crew. One condition of use, about the substrate, which nobody reads because the first job passed.

How an inspector reads one

An inspector looking at a report on site usually reads it in this order, which is a fair checklist for the person who chose the product: is it current (checked on the evaluation service's own site, not from the printout); is the product on the box the product in the report; does the report list this edition; does it name this use; and are the conditions of use met as built. They will compare a fastener spacing or a sheathing thickness with the table, and they will look for the product's identification marking. A report they cannot connect to the material in front of them is not much use to them. Reading a report step by step before you buy the product is its own procedure. See related: How to Read an Evaluation Report Before You Use a Product.

References

• International Residential Code R104.11 and International Building Code 104.11, 2021 editions, alternative materials, design and methods, as adopted by your jurisdiction (relocated in the 2024 editions).
• ISO/IEC 17065, conformity assessment requirements for bodies certifying products, the accreditation basis for evaluation services.
• The evaluation service's own online directory, for a report's current status and revision history.
• See related: Field Evaluation When a Product Has No Listing; How to Request Approval for an Alternative Method.