Editorial Policy

What we cover

One-component spray foam insulation kits, two-component canister systems, wide-spray cans, foam sealants by job, and the guns, cleaners and nozzles around them. Caulk, grout and pastes are out of scope whatever claim they carry. Professional high-pressure spray foam systems, the truck- or rig-mounted equipment a contractor buys by the drum set, are out of scope as well: nothing on this site rates them, and a page that addresses contractors is addressing the portable products they can buy in a box.

What "best" means here, and what is in the record

"Best" on any page of this site means best among the products we have researched, ranked by the printed criteria, and not best of everything sold in the United States. Products enter the record through a marketplace intake that we screen by hand, which on the date above means the intake is led by what is listed on Amazon and, for some products, the maker's own store; the intake decides what we look at first, never how a product scores. A product that is not in the record has not been judged; it has not been reached. That includes some widely sold retail lines and some of the best-documented products in the sector, and where a page names one it says so. Makers, sellers and readers can put a product forward through the submissions page, and the exact type, variant and pack size are what we take in, because those are what the documents cover. Whether a product can be bought through an affiliate link is not a criterion for taking it in, keeping it or placing it.

What counts as evidence, in order

1. A technical data sheet from the maker with a date or a revision number on it.
2. A safety data sheet, a test report, a code evaluation report or a registration number that can be looked up.
3. A statement on the maker's own web store, quoted with its date.
4. A marketplace listing title or bullet, quoted with its date, and treated as the weakest source because it changes without notice.
5. Buyer reviews, read for patterns and never as performance measurements. How we read them.

A claim that names a standard without a result, or a result without the tested thickness, is recorded as incomplete. A missing document is recorded as missing, which is a finding, not an oversight. We do not fill gaps with assumptions.

Scores and marks

Insulation kits carry a 100-point research rating built from documents, traceability, kit contents, price and feedback, with every awarded point and its reason printed on the product page, and a separate confidence level that never changes the arithmetic. Foam sealants carry four yes-or-no evidence marks instead, because half their makers publish nothing and a score built on nothing would look like knowledge; what the "claim checkable" mark tests differs by category and each category page says which. Guns, cleaners and nozzles carry neither: that page reports what each maker publishes and orders the list by feedback base, and it says so. All of these are statements about what is documented. None is a performance test.

What no one can buy

A position, an eligibility decision, a score, a mark, a softer sentence, or the removal of an open question. We accept no payment, product, sample, sponsorship or advertising from any maker or seller we cover. The one income the site has is the Amazon Associates fee on qualifying purchases, which no maker pays and which is not a criterion in any score. If that changes, the policy changes first and the page says so. See Ownership and conflicts.

How we write

US English, for homeowners and contractors. Every figure names its source and the date it was read. Prices are dated snapshots. We quote makers in their own words when the wording is the point. We say "we have not seen" when we have not seen, and we do not describe a product as unsafe, non-compliant or illegal on the basis of a missing document; the finding we publish is that the claim cannot be checked by the person buying it.

The Spanish edition

Every page has a Spanish edition for US readers, under /es/. It is the English page in Spanish, not a second opinion: the figures, units, dates, sources and scores are the English page's own, and a Spanish page cannot go out while any sentence on its English page is untranslated. The translation itself is made with AI assistance and read by the Best Spray Foam research desk; no outside translator has reviewed it. Where the two editions ever differ, the English page is the one that counts, and each Spanish page links to it.

Who writes it

A small research desk that reads documents for a living and has no background as a manufacturer, laboratory, code official or contractor. That is stated on every page that could be mistaken for a test, and it is why the site links to the label, the data sheet and the local code rather than standing in for them. Makers who think we have read their documents wrong can send the documents; every submission is read against the record, and that page says what happens to it.