{"id":1795,"date":"2026-04-20T11:06:49","date_gmt":"2026-04-20T03:06:49","guid":{"rendered":"https:\/\/bopinchem.com\/?p=1795"},"modified":"2026-04-20T11:10:11","modified_gmt":"2026-04-20T03:10:11","slug":"selantes-corta-fogo-para-penetracoes-de-tubos-e-cabos-o-guia-completo-para-especificadores","status":"publish","type":"post","link":"https:\/\/bopinchem.com\/pt\/firestop-sealants-for-pipe-and-cable-penetrations-the-specifiers-complete-guide\/","title":{"rendered":"Selantes corta-fogo para penetra\u00e7\u00f5es de tubos e cabos: o guia completo do especificador"},"content":{"rendered":"
\"Firestop
<\/figcaption><\/figure>\n\n\n\n

Every building has them. Every fire safety audit looks for them. And in a significant proportion of building fires, they are the reason fire travels where it should not.<\/p>\n\n\n\n

Penetrations \u2014 the gaps where pipes, cables, conduits, cable trays and ducts pass through fire-rated walls and floors \u2014 are the most common failure point in a building’s passive fire protection system. A single unsealed cable bundle passing through a fire compartment wall can effectively negate the entire fire rating of that wall, allowing fire and smoke to spread freely across floors and zones that should have remained isolated.<\/p>\n\n\n\n

The solution is firestopping. Properly specified and installed firestop sealants and foams restore the fire resistance of the penetrated element \u2014 maintaining the compartmentation strategy that gives occupants time to evacuate and fire crews time to intervene.<\/p>\n\n\n\n

This guide is written for M&E contractors, passive fire protection installers, fire safety engineers, and construction project managers who need to specify and procure firestop products correctly. It covers the technical requirements for different penetration types, the standards that govern fire-rated sealing, product selection between sealants and foams, and the documentation requirements that increasingly form part of building inspection and handover.<\/p>\n\n\n\n

\n\n\n\n

1. Why Penetration Sealing Is the Critical Weak Point in Passive Fire Protection<\/h2>\n\n\n\n

Fire compartmentation only works if every penetration through every compartment boundary is properly sealed.<\/strong><\/p>\n\n\n\n

The Compartmentation Principle<\/h3>\n\n\n\n

Passive fire protection divides a building into fire compartments \u2014 zones bounded by walls, floors and ceilings that carry a defined fire resistance rating, expressed in minutes or hours. The principle is straightforward: contain a fire within its compartment of origin long enough for evacuation to complete and suppression systems or fire services to respond.<\/p>\n\n\n\n

A compartment wall rated at EI 120 (120 minutes of fire integrity and insulation) is meaningless if a 50mm steel pipe passes through it with a 10mm annular gap packed with mineral wool and nothing else. Without a tested and certified firestop system at that penetration, the pipe itself becomes a thermal conductor \u2014 and the gap around it becomes a smoke and flame pathway.<\/p>\n\n\n\n

Smoke inhalation, not direct flame contact, causes the majority of fire deaths in buildings. Even a small unsealed gap allows lethal smoke concentrations to spread rapidly across compartment boundaries, often well before the structure itself is threatened.<\/p>\n\n\n\n

Why Penetrations Multiply Faster Than Firestopping Keeps Up<\/h3>\n\n\n\n

In commercial construction, penetrations accumulate throughout the project lifecycle. The initial M&E design may specify a certain number of pipe and cable routes. By the time fit-out and tenant modifications are complete, the actual number of penetrations through any given fire wall may be three to five times the original count.<\/p>\n\n\n\n

Each addition \u2014 a new data cable run, an additional pipe for a tenant fit-out, a conduit for a security system \u2014 creates a new penetration that requires a certified firestop installation. In practice, late-stage and post-occupancy penetrations are the most commonly unsealed, because the fire protection inspection has already passed and the work is carried out under general maintenance or fit-out contracts without adequate oversight.<\/p>\n\n\n\n

The specifier’s role is to establish systems and materials that are practical to install correctly the first time \u2014 and to document them in a way that survives the building handover and future modification cycles.<\/p>\n\n\n\n

The Consequences of Non-Compliance<\/h3>\n\n\n\n

In jurisdictions where building codes enforce passive fire protection requirements \u2014 which includes most of Europe under EN standards, the Gulf states under IBC\/NFPA or local equivalents, and Southeast Asia under national building codes \u2014 an unsealed penetration is a code violation with direct liability consequences.<\/p>\n\n\n\n

Insurance policies for commercial buildings increasingly require documentary evidence of firestop compliance. In the event of a fire, an unsealed penetration that allowed spread can result in coverage denial, civil liability, and in severe cases, criminal prosecution of the parties responsible for the installation.<\/p>\n\n\n\n

\n\n\n\n

2. Penetration Types and Their Sealing Requirements<\/h2>\n\n\n\n

Different penetrations require different firestop approaches. Specifying the correct product starts with understanding the penetration type.<\/strong> <\/p>\n\n\n\n

\"Types
<\/figcaption><\/figure>\n\n\n\n

Steel and Copper Pipes<\/h3>\n\n\n\n

Steel and copper pipes do not burn. In a fire scenario, they conduct heat but do not contribute fuel. The primary concern at a steel or copper pipe penetration is the annular gap \u2014 the space between the pipe’s outer diameter and the edge of the hole through the wall or floor.<\/p>\n\n\n\n

For small-diameter pipes (up to approximately 160mm) with annular gaps up to 25mm, a fire-rated sealant applied to the full depth of the wall or floor thickness at the penetration is typically the correct approach. The sealant must bond to both the pipe surface and the surrounding concrete, masonry or gypsum board, creating a continuous fire and smoke barrier.<\/p>\n\n\n\n

For larger-diameter pipes or larger annular gaps, a combined system is often required: mineral wool packing to fill the majority of the gap, with fire-rated sealant applied over the mineral wool as the final seal. The mineral wool backing must meet minimum density requirements \u2014 typically 40 kg\/m\u00b3 \u2014 to maintain its integrity under fire conditions.<\/p>\n\n\n\n

Plastic Pipes (PVC, HDPE, PP)<\/h3>\n\n\n\n

Plastic pipes present a more complex sealing challenge. Unlike steel or copper, plastic pipes will melt and burn in a fire, leaving an open hole in the fire wall at exactly the moment containment is most needed.<\/p>\n\n\n\n

The standard approach for plastic pipe penetrations is an intumescent collar \u2014 a device containing graphite-based material that expands dramatically when exposed to heat, compressing inward to seal the hole left by the melting pipe. Intumescent collars are installed around the pipe at the wall or floor face and must be specified to match the pipe diameter precisely.<\/p>\n\n\n\n

Fire-rated sealant is used in conjunction with intumescent collars to seal the annular gap between the collar housing and the wall opening, and sometimes to provide additional protection on the unexposed face of the penetration. The sealant alone \u2014 without an intumescent collar \u2014 is generally not acceptable for plastic pipe penetrations, because the sealant cavity will become void when the pipe melts.<\/p>\n\n\n\n

Cable Bundles and Individual Cables<\/h3>\n\n\n\n

Cable penetrations are the most common and, statistically, the most frequently left unsealed. A typical commercial building may have hundreds of cable penetrations through fire-rated elements, created incrementally over the building’s life as data, power and communication systems are added and modified.<\/p>\n\n\n\n

For cable penetrations, fire-rated sealant is the primary sealing method. The sealant is applied to fill the annular gap between the cable bundle and the wall opening on both faces of the wall, penetrating into the depth of the opening to create a continuous barrier.<\/p>\n\n\n\n

The key challenge with cable penetrations is accommodating future modifications \u2014 additional cables added after the initial installation. Fire-rated sealants that remain permanently elastic allow cables to be added without fully breaking the seal, though any significant modification should be followed by resealing.<\/p>\n\n\n\n

For heavy cable tray penetrations, a combination of mineral wool packing and fire-rated sealant over-coating is typically specified, following the same approach as large-diameter pipe penetrations.<\/p>\n\n\n\n

Conduits and Trunking<\/h3>\n\n\n\n

Metal conduits and trunking are generally treated similarly to steel pipes \u2014 the conduit itself will not burn, so the sealing requirement focuses on the annular gap around the conduit and, critically, the interior of the conduit itself.<\/p>\n\n\n\n

An open conduit running through a fire wall is effectively a chimney \u2014 it channels smoke and hot gases directly through the compartment boundary via the conduit interior. Firestopping at conduit penetrations must therefore address both the annular gap around the conduit and the conduit bore.<\/p>\n\n\n\n

For conduit bores, fire-rated foam is the most practical solution. The foam can be injected into the conduit through the wall opening to a specified depth, creating an internal plug that blocks smoke and fire transmission through the conduit.<\/p>\n\n\n\n

HVAC Ducts and Mechanical Penetrations<\/h3>\n\n\n\n

HVAC duct penetrations through fire-rated elements require fire dampers \u2014 mechanical devices that close automatically in response to heat \u2014 rather than sealant-based firestopping. Fire dampers are regulated separately and fall outside the scope of this guide. However, the annular gap between the duct casing and the wall or floor opening does require a firestop sealant installation around the duct perimeter.<\/p>\n\n\n\n

\n\n\n\n

3. Understanding EN 1366-4 and Fire Resistance Classifications<\/h2>\n\n\n\n

Knowing which standard applies to your project is not optional \u2014 it determines which products are legally acceptable.<\/strong><\/p>\n\n\n\n

What EN 1366-4 Tests and Certifies<\/h3>\n\n\n\n

EN 1366-4<\/a> is the European test method for linear joint seals \u2014 the standard under which firestop sealants and systems for linear joints and penetrations are tested and classified. It is the primary standard for firestop sealant certification in Europe and is increasingly referenced in international specifications outside Europe.<\/p>\n\n\n\n

The test subjects a joint or penetration assembly to a standardised fire exposure (the ISO 834 temperature-time curve) and measures performance against two criteria:<\/p>\n\n\n\n

Integrity (E):<\/strong> The ability of the assembly to prevent the passage of flames and hot gases. Failure occurs when flames or hot gases penetrate through the specimen.<\/p>\n\n\n\n

Insulation (I):<\/strong> The ability of the assembly to limit the temperature rise on the unexposed face to 180\u00b0C above ambient. Failure occurs when any point on the unexposed face exceeds this limit.<\/p>\n\n\n\n

A product achieving EI 120 under EN 1366-4 has maintained both integrity and insulation for 120 minutes under standardised fire conditions. EI 60, EI 90, EI 120, EI 180 and EI 240 are the common classifications encountered in building specifications.<\/p>\n\n\n\n

Critical caveat:<\/strong> Fire resistance ratings are configuration-specific. A product achieving EI 120 in a 150mm concrete wall with a 20mm \u00d7 20mm joint does not automatically achieve EI 120 in a 100mm gypsum board wall with a 30mm \u00d7 30mm joint. The rating applies to the specific tested system \u2014 wall type, thickness, joint dimensions, backing material, and sealant depth. Installations that deviate from the tested configuration cannot claim the tested fire rating.<\/p>\n\n\n\n

BS 476 Part 20 and International Equivalents<\/h3>\n\n\n\n

BS 476 Part 20<\/a> is the British Standard method for testing fire resistance of building elements. It predates EN 1366-4 and uses a similar approach but with some procedural differences. Products tested to BS 476 Part 20 carry EW or EI classifications under the British system.<\/p>\n\n\n\n

In markets transitioning from BS to EN standards \u2014 including many Commonwealth countries, the Gulf states, and parts of Southeast Asia \u2014 specifications may reference either or both standards. When a project specification references BS 476 Part 20, verify whether EN 1366-4 is also acceptable before substituting products certified under only one of the two standards.<\/p>\n\n\n\n

In the United States and markets following US codes (some Gulf projects, Philippines), UL 1479<\/a> (ANSI\/UL 1479 \u2014 Fire Tests of Through-Penetration Firestops) is the applicable standard. Products must carry UL classification for use on US-code projects.<\/p>\n\n\n\n

What the Specification Should State<\/h3>\n\n\n\n

A properly written fire protection specification for penetrations should identify:<\/p>\n\n\n\n