How to Specify Firestop in a Tender That Holds Up on Site

One line in a tender does more damage than any other: supply and install firestopping to achieve 60 minutes, product by an approved manufacturer. It looks finished. It has a time in it and it sounds like quality. On site it means whatever the cheapest honest reading of it means. By the time anyone argues, the walls are already closed.

How to specify firestop in a tender comes down to a single shift in thinking. A weak clause names a product. A strong clause names a performance and the tested arrangement that delivers it, then demands the paperwork that proves both. Get that right and the rest of the package polices itself.

This is written for the person drafting the document, not the person answering it. Simfy Exim supplies passive fire protection product into Europe and Africa, which means we read these documents from the tendering side every week and see exactly where they leak.

Why a firestop specification fails

Consider what a contractor does with that opening line. Sixty minutes could mean integrity alone or integrity with insulation, and those are materially different products at materially different cost. An approved manufacturer is not defined anywhere in the document, so approval becomes self declared. And because no submittal is demanded before work starts, the first time anyone examines the evidence is at handover, when the only remedy left is opening finished construction. None of that is dishonesty. It is a document that asked a vague question and got a literal answer. The fix is not longer text. It is text that can be checked, item by item, by somebody who was not in the room when it was written.

Specify a classification, not a duration

The letters carry the substance. Integrity is the ability to stop flame and hot gas passing to the unexposed side. Insulation is holding the temperature of that unexposed side below a limit. A penetration that keeps flame back but runs hot can still set fire to what leans against the wall in a stairwell. Deciding which of those you need is a design decision belonging in the specification, not a pricing decision belonging to a subcontractor. Where legacy evidence appears, be explicit about which regime governs. In the United Kingdom, BS 476-20:1987, the method for determination of the fire resistance of elements of construction, still turns up in existing building records, and Approved Document B is withdrawing those national classes in favour of the BS EN 13501 series. A document that accepts either, without saying so, will receive both.

Require the tested arrangement, and its limits

BS EN 1366-3:2021 is unusually direct about this. It sets out criteria for evaluation including field of direct application rules, which define how far a laboratory result may be extended before fresh testing or a written assessment becomes necessary. It also states that supporting constructions represent separating elements such as walls or floors, simulating the interaction between the test specimen and the element the sealing system will sit in. Linear gaps are a separate question again, handled by BS EN 1366-4:2021, which assesses joint seals by intended end use, both with and without mechanically induced movement, and excludes curtain walling perimeter seals. So the clause should name the parts that apply. Requiring evidence to BS EN 1366-3:2021 for penetrations and BS EN 1366-4:2021 for movement joints removes the single most common gap in these packages.

Demand the evidence pack by name

For product placed on the European market the anchor document is defined in law. Regulation (EU) No 305/2011, the Construction Products Regulation, requires in Article 4(1) that a manufacturer shall draw up a declaration of performance when a product covered by a harmonised standard is placed on the market. Article 6(1) requires the declaration to express performance against the essential characteristics, and Article 6(3)(c) requires performance for at least one essential characteristic relevant to the declared intended use. Article 8(2) closes the loop: where no declaration has been drawn up under Articles 4 and 6, the CE marking shall not be affixed. For projects in Great Britain, GOV.UK guidance on the Construction Products Regulation confirms that harmonised European standards became designated standards, and that a product carrying both UKCA and CE marks needs valid declarations satisfying both regimes.

The firestop schedule is the clause people forget

Ask for it early, before first fix, and ask for it to be updated as services change, because they always do. The schedule is what turns an argument about quality into an arithmetic check. It also carries the coordination problem into the open, since a partition with fourteen services through it is a design issue rather than a sealing issue, and it is far cheaper to move a service on paper. Make the schedule a submittal with a named approver and a date, not an appendix that appears at handover. On multi building programmes this is also the document that lets a buyer aggregate real quantities across sites, which is where our sourcing and supply solutions become useful rather than theoretical.

The as built register, and why it now matters legally

The Building Safety Act 2022 created the building safety regulator and set duties around higher risk buildings, including registration, certificates and accountable persons, alongside provisions on construction product liability. GOV.UK guidance on keeping information about a higher risk building describes the golden thread as a digital record that acts as a building single source of truth, kept accessible and written in plain English, and places that duty on clients, principal designers, principal contractors and accountable persons. Firestopping evidence is exactly the kind of information that ends up in it. Specifying the register at tender stage costs nothing. Reconstructing it two years later, from memory and a folder of delivery notes, is close to impossible, and the photographs that would have settled it no longer exist because the ceilings went in.

Make substitution a controlled event

The reason is technical rather than contractual. Because a class attaches to the arrangement that was tested, swapping in a different material at the same stated minutes changes the configuration unless separate evidence covers it. Two products can hold identical classifications and still be assessed in different wall constructions. The clause should therefore ask for the report, not the assurance. It should also name who approves, because a substitution approved by a site manager under time pressure is how a compliant specification becomes a non compliant building. Buyers who want the comparison done properly before an order is placed can send both options to Simfy Firesys and get the evidence read against the actual drawings.

Separate supply from installation

When a seal fails, there are only two possible causes: the wrong product was supplied, or the right product was installed outside its tested arrangement. A single combined line gives the responsible party an incentive to keep that question unanswered. Splitting the scopes forces the evidence to sit with the supply package, where it can be checked before delivery, and forces the installation method statement to reference the approved detail sheet. It also removes an argument that has become common on tenders using centrally purchased product, where a contractor declines responsibility for goods it did not select. Say who selects, who supplies, who installs and who verifies, in four sentences, near the front of the document. Our working process is written around that split, because it is the one we operate on.

What to ask a supplier to produce before you order

Put these in the tender as submittals rather than requesting them later. A supplier who cannot produce them at enquiry stage will not produce them at delivery either.

• The declaration of performance for each product code you intend to buy, matched to packaging
• The classification report showing the class in letters and minutes and the standard it was issued against
• The underlying test or assessment report, so the tested arrangement can be read in full
• Installation details covering every element type on your drawings, including the awkward ones
• Confirmation of the manufacturing site, with the option of a factory audit and pre shipment inspection
• Batch marking and shelf life terms, with a minimum remaining life on delivery

If a market outside Europe governs the project, ask which evidence the local authority accepts before the enquiry goes out. Certification regimes differ between European and African markets, and in the United States a separate framework applies, where ASTM E814-26, the Standard Test Method for Fire Tests of Penetration Firestop Systems, produces an F rating based on flame occurrence on the unexposed surface and a T rating based on temperature rise as well as flame. Deciding that at drafting stage is a paragraph. Deciding it at customs is a delay.

When we are not the right fit

We supply and source product. We do not install, we are not a fire stopping contractor, and we do not survey buildings, write method statements or sign off workmanship. If your tender needs an installer, a competent person to certify installed work, or a remedial survey of existing penetrations, we are not that company and we will tell you at the first enquiry rather than the third meeting.

We are also careful about what certification means on our side. Any approval or listing sits with the manufacturers who make the goods. We do not hold it and we do not present it as ours. What we contribute is requirement led sourcing against a written specification, supplier verification, factory audit and pre shipment inspection where wanted, and open book pricing so you can see what you are paying for.

Knowing how to specify firestop in a tender is mostly a drafting discipline. If you are drafting a package now and want the evidence requirements checked before it goes out, send the specification and drawings through our requirement form. Common questions are answered on our frequently asked questions page, and if it is easier to talk it through, reach the team directly.