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Legislation for Firestopping


Principle Control of Fire Spread and limitation of damage is principally achieved through compartmentation of a building.

These compartments are bounded by fire resisting elements:-

  • Walls
  • Floors
  • Ceilings

Fire resisting elements are often breached to permit access for services or functional joints:-

  • Cables
  • Pipes
  • Ventilation systems
  • Gaps between fire resisting elements and around the penetrations must be sealed so that the fire integrity of the fire – resisting element is maintained.

National regulations

The following national regulations are published as statutory instruments by Parliament with respect to life safety purposes:-

Building Regulations (England & Wales) 1991

  • These regulations are expressed as functional requirements.
  • Approved Document B (2007 Edition) Fire Safety, gives non- mandatory guidance.

Building (Scotland) Regulations 2004 

  • They are expressed as mandatory expanded functional standards found in Schedule 5 to Regulation 9
  • Non- mandatory guidance on compliance is given in Section 2 of both Domestic and Non-domestic Technical Handbooks

Building Regulations (Northern Ireland) 1994

Basic functional requirements with approval solutions are given in Technical Booklet E, which is similar to the England and Wales Approved Document B.

Building Regulations (Republic of Ireland) 1997 

The Building Regulations in the Republic of Ireland are similar in arrangement and content to the England and Wales Building Regulations, and are covered by Technical Guidance Document B.

Why does Firestopping need to be carried out?

 Approved Document B states the following with regards to re-instatement of fire rated elements:-

“If a fire separating element is to be effective, then every joint, or imperfection of fit, or opening to allow services to pass through the element, should be adequately protected by sealing or firestopping so that the fire resistance of the element is not impaired” 10.2 

This is quite categorical in its assertion that every opening in a fire rated element needs to be re- instated.

“In addition to any other provisions in this document for firestopping:

a. joints between fire separating elements should be firestopped; and

b. all openings for pipes, ducts, conduits or cables to pass through any part of a fire separating element should be:

i.kept as few in number as possible, and

ii.kept as small as practical, and

iii. firestopped (which in the case of a pipe or duct, should allow for thermal movement).” 10.17

The final sentence stating that firestop materials should allow for thermal movement rules out the use of sand/cement and concrete for filling round services.

 The Scottish Technical Handbooks make a very similar recommendation about movement. Movement is a major consideration of services as they are usually supported independently of the wall or floor and therefore will be subject to differential movement.

The Non Domestic Technical Handbook also states:

“ Compartment walls and compartment floors (including a fire resisting ceiling) are intended to prevent fire passing from one compartment to another. Openings and service penetrations through these walls or floors can compromise their effectiveness and should be kept to a minimum. The solum and roof space should not be forgotten. Openings and service penetrations should be carefully detailed and constructed to resist fire.” 2.1.15

” Where a wiring system passes through elements of building construction such as floors, walls, roofs, ceilings, partitions or cavity barriers, the openings remaining after passage of the wiring systems shall be sealed according to the degree of fire resistance required of the element concerned” 527- 02- 01

” Where a wiring system such as a conduit, cable ducting, cable trunking, busbar or busbar trunking penetrates an element of building construction having specified fire resistance it shall be internally sealed so as to maintain the degree of fire resistance of the respective element as well as being externally sealed to maintain the required fire resistance” 527- 02- 02

Why do you have to have all your Firestop products tested?

The Building Regulations, Approved Document B states the following with regards to testing:-

” the… product…should be in accordance with a specification or design which has been shown by test to be capable of meeting that performance or have been assessed from test evidence against appropriate standards” Appendix ‘A’ 1a

” Provide .. propriety fire-stopping and sealing systems which has been shown by test to maintain the fire resistance of the wall or other element” 10.19

The Scottish Technical Handbooks state:

” Fire-stopping may be necessary to close an imperfection of fit or design tolerances between construction elements and components, service openings and ventilation ducts. Propriety fire- stopping products, including intumescent products, should be tested to demonstrate their ability to maintain the appropriate fire resistance duration under the conditions appropriate to their end use.”

Regulations and Guidelines

‘Hilti Firestop products are tested to current international standards. Hilti Firestop is tested to BS 476 and now to EN 1366, a more stringent and pertinent standard. Based on this comprehensive level of global testing Hilti are able to obtain assessments and engineered judgements for a wide range of non-standard applications making it the leader in firestopping internationally.’

Why does Hilti insist that our Specialist Contractors are members of a 3rd party accreditation scheme?

The Building Regulations, Approved Document B states the following with regards to accreditation of installers:-

” Third party accreditation of installers of systems, materials, products or structures provide a means of ensuring that installations have been conducted by knowledgeable contractors to appropriate standards, thereby increasing reliability of the anticipated performance in fire” 0.15

The Scottish Technical Handbooks state:

“Some methods of establishing workmanship are…. the workmanship is covered by a scheme, which complies with the relevant recommendations of BS EN 9000: Quality management and quality assurance standards (there are also independent schemes of accreditation and registration of installers of materials and products that provide a means of ensuring that the work has been carried out by knowledgeable contractors to an appropriate standard)” The Fire Protection Association Essential Principles Document ( representative of the UK insurance industry) states: “All fire protection products/systems should be installed by adequately trained specialist installers. Installers shall be third party certified to install the specific products/system when an appropriate scheme is available (e.g. FIRAS or LPCB)” Principle 11

All our accredited contractors are current members of FIRAS. FIRAS is a UKAS accredited scheme run by the Warrington Fire Research Establishment.

Why has Hilti gone to the trouble of having their Firestop products approved under the LPCB certification scheme?

The Building Regulations, Approved Document B states the following with regards to accreditation of products: 

” Third party accredited product conformity certification schemes not only provide a means of identifying…products…which have demonstrated that they have the requisite performance in fire, but additionally provide confidence that the…products…actually supplied are provided to the same specification or design as that tested/assessed” 0.15

 We meet the recommendations by having products certified by LPCB. There have proven cases in the past, of companies changing the formulation of their product without retesting it. This cannot happen with Hilti’s LPCB accredited products and therefore, they offer greater security to specifiers, building owners and contractors.

Who carries liability for poor or incomplete Firestopping?

During construction of a building a number of different pieces of legislation and guidelines apply.

Where do they apply?

On all construction sites and in buildings undergoing renovation.

Who is responsible?

At this stage, both the designers and constructors of the building have a responsibility. From the constructors’ side the ultimate responsibility will lie with the main contractor but all sub contractors will have a duty to ensure that they also comply.

What is their responsibility?

The Joint Code of Practice on the Prevention from Fire of Construction Sites states:-

” Construction works should be designed, planned and sequenced to achieve the early installation and operation of:-

(a) Permanent fire escape stairs, including compartment walls;

(b) Fire compartments within the building under construction, including the installation of fire doors, and the completion of fire stopping with special attention given to lift shafts, service ducts and voids which offer a passageway to heat and smoke” 8.1 

The Construction Design and Management Regulations 2007

Places duties of care on all who are involved in a construction project. Sufficient knowledge and competence by all involved has to be ascertained, whether designing or executing the work and the reduction or elimination of risks to health and safety must be achieved, not only for those involved in the construction process but also the end users of the building. Fire is an ever present hazard during the construction period (11 fires a day on UK construction sites- HSE) and also in occupied buildings.’

After commissioning of a building the Regulatory Reform (Fire Safety) Order comes into force for England & Wales.

Where does it apply?

It applies to all workplaces where staff are employed with a few exceptions such as mines, offshore, etc where other regulations apply.

Who is responsible?

Every employer shall appoint a ‘Responsible Person’ who has to ensure that their company complies with the requirements of these regulations in respect of every workplace, which is to any extent under their control.

What is their responsibility?

To carry out an annual risk assessment on their premises which includes identifying any structural features that could promote the spread of fire and, where possible, taking steps to reduce the potential for rapid fire growth. The workplace may contain features that could promote the rapid spread of fire, heat or smoke and affect escape routes. These features may include ducts or flues, openings in floors or walls, or combustible wall or ceiling lining. Where people are put at risk from these features, appropriate steps should be taken to reduce the potential for rapid fire spread or to provide an early warning of fire so that people can leave the workplace before their escape routes become unusable.

In Scotland The Fire (Scotland) Act 2005 applies in the way the RRO does in England & Wales.

Similar requirements of the Act are made through the provisions of the Fire Safety (Scotland) Regulations 2006. Both Act and Regulations impose duties and are not to be considered in isolation. Information about the regime and guidance can be had by visiting www.infoscotland.com/firelaw. In essence, employers have a duty to protect their employees and users of their building from the hazard of fire. A fire risk assessment must be carried out and maintained. The employer has to implement risk reduction measures and these extend to more than fire drills, alarms, escape ways and extinguishers. The fabric of the building is also included, so compartmentation, where it is part of the building, has to be maintained. This means that all service penetrations and imperfections of fit require to be sealed. Prosecutions under this legislation carry a fine of £20,000 and/or 2 years imprisonment.’

Thank you to Hilti for allowing Breakfire Ltd to reproduce this information.

 Firestop Application & Problem Checklist for Hilti Materials

 Head of wall joint

  • If differential movement is expected, an elastomeric system must be used that is capable of meeting the design requirement – CP601S (± 25%)
  • Profile deck – ensure that there are no gaps for smoke to pass through, particularly in suspension nut grooves. Seal with a suitable sealant – CP606 / CP672
  • If services penetrate the head of wall joint they have to be sealed with an appropriate intumescent material – CP611A, CP606, CP601S

Wall / floor joints

  • If movement is expected, seal with elastic sealant capable of the design requirements. Check for cracking of the seal – CP601S (± 25%), CP606 (±12%)
  • If slab edge / cladding joints are firestopped with rigid mineral wool systems, supporting brackets must be fixed at a safe distance from the slab edge. All gaps must be filled with sealant and joints between boards taped. Cladding movement must be  adequately accommodated by a flexible seal that has adhered to the concrete slab and the cladding – CP672, CP604

Plastic pipes

  • Wall penetrations must have a pipe collar or wrap fitted to each face unless the product has been successfully tested in a centrally mounted position – CP643N, CP649, CP645
  • Floor penetration must be firestopped from the underside of the floor slab
  • Pipe collars must be fitted hard against the compartment wall / floor face
  • All collars must be secured to the base material using fire rated fixings
  • Collars and wraps should carry test certificates for the appropriate type of pipe eg ABS, PE, HDPE, etc.
  • Collars should not be fitted over pipework joints

Metal pipes

  • Seals must be flexible to allow movement – CP601S
  • If cement has been used it must be reinforced and applied to the full depth of the wall or floor
  • Insulated pipes must be sealed with a pressure exerting intumescent product to cope with burning insulation – CP645,CP611A, CP643N, CP649
  • Sleeves around pipes must be firestopped inside and outside – CP601S, CP606, CP611A


  • Dampers must be installed in line with compartment walls and floors
  • Dampers to be secured with mechanical installation frames in accordance with manufacturers’ instructions
  • Dampers in solid wall to be firestopped using compound – CP637, CP638
  • Dampers in drywall should be fixed to studding by a fixing plate and sealed with batts that have been suitably tested for the application – CP670

Trays / baskets

  • Fireseal has to be capable of expanding to replace plastic sheaths on cables such as armoured and bunched computer installations – CP611A, CP657
  • If further cables are to be added firestopping to be repenetratable – CP651N, CP657
  • To ensure insulation ratings cable trays may need to be coated back in accordance with manufacturers’ recommendations

Single cables

  • Smaller single cables can usually be sealed with a low intumescent sealant – CP606

Bunched cables

  • Firestop has to be a pressure exerting intumescent product capable of replacing platic sheaths on cables such as armoured and bunched computer installations – CP611A, CP657

Metal trunking

  • Cables within trunking to be firestopped where they pass through compartment wall / floor – CP651N, CP657
  • Short piece of trunking lid to be applied over firestopping to aid inspection
  • Trunking should also be sealed around the outside Compartmentation Guide


  • Floor openings for service shafts must be sealed with a loadbearing fireseal – CP638
  • Plastic pipes passing through compound seals have to have the correct collar or wrap fitted. If cast into the compound pour they must be exposed on the underside face – CP643N, CP649
  • Insulated pipes should be sealed with a pressure exerting intumescent product or have the insulation removed for the depth of the seal – CP643N, CP649, CP611A
  • HVAC dampers should be secured with an installation frame

Electrical sockets

  • All electrical sockets in fire rated partition walls should be fire and acoustically sealed. This can be either by the installation of a baffle box or by the easier method of fixing a putty pad to either the interior or rear of the back box – CP617

Flat plastic duct

  • The ducting will need to be sealed where it passes though a fire rated wall – CP648
  • If firestop material can only be applied to 3 sides (ie where the duct is fixed tightly to a soffit), it needs to be confirmed that the product has been tested in this scenario

Access flooring / suspended ceiling

  • A fire rated compartmentation wall is designed to go from the base of the floor slab to underside of the next floor slab. The firebreak must continue beneath an access floor and above the suspended ceiling in order to achieve the same fire and insulation rating as the rest of the wall – CP670, CP657

Fire doors

  • Door frames must be secured using fire rated fixings – HUS, HT, HRD
  • Gap between frame and wall must be sealed to the same fire and insulation rating as the door – CF125

One component fire rated foams

  • Although many cans will state “up to 4 hours fire integrity” this will generally have been tested in a very restricted environment. This usually consists of an opening 15mm in diameter and 200mm deep. The lack of available oxygen in such a small hole will mean that the flame cannot be sustained and the test will achieve 4 hours. When the size of the opening is increased and a more realistic 100mm depth is tested, this may burn through in under 10 minutes. The products are rarely tested around services and do not exert any pressure in a fire so should never be used around plastic components. Hilti’s recommendation is that single component polyeurethane foams should only be used as a backing material for a tested firestop product

General situations to be considered

  • Has the firestopping been carried out by 3rd party accredited contractors (FIRAS, LPS) as recommended in the Building

Regulations and by the Insurance Industry?

  • Have the products that have been installed been 3rd party accredited (LPCB, Certifire, FM) as recommended in the Building Regulations and by the Insurance Industry?
  • Do all the solutions have valid test certificates or, where no direct test evidence is available, is there an assessment, engineering judgement or engineered solution that has been compiled by a suitably qualified engineer?
  • Have the firestop materials been age tested. No one knows when a fire is likely to break out and so the firestop should have a life expectancy equivalent to the building (min 25 years)
  • Have all plastic pipes below 40mm been firestopped as stated in 11.7 of Approved Document B?
  • Has the coated batt ever been tested in a full scale (3 metre) drywall? Batts only tested in solid walls cannot be assed for use in drywall although the reverse is acceptable
  • Is the insulation rating of the product the same in minutes achievable as the fire integrity. Approved Document B gives the same value for both in all circumstances
  • Is the installation in accordance with all the manufacturer’s instructions and recommendations
  • Have all the services been independently supported and are the fixings suitable?
  • Have all the applications been labelled and recorded?
  • Ensure that no glass wool has been used around penetrations or in joints (eg Cornings Pink)
  • Ensure that no loose fill mineral has been used around penetrations or in joints without a suitable covering of firestop material
  • Are there chemicals present that might affect the performance or installation of firestop materials?
  • Will the firestop materials be subject to extremes of temperature and can they cope?
  • Have all possible routes for smoke, gas and flame been sealed?
  • Ensure that an ongoing inspection regime has been put in place to ensure that installations are not compromised in the future Compartmentation Guide 2007

Thank you to Hilti for allowing us to reproduce this information