Portal Steel Framed Building & Fire Regulations

Portal Steel Framed Buildings & Fire Regulations

Is your current building fit for purpose ?

Does your new building adhere to fire regulations ?

Has your building been designed with fire boundary conditions taken in consideration ?

In the United Kingdom Building Regulations require all portal steel framed buildings to maintain its structural stability when exposed to fire.

Regulations can vary in UK Countries but generally a portal steel framed building is required to retain its load bearing capacity for a reasonable time to allow occupants to safely escape from the building.

The regulations vary depending on the size, use of the building and its position in relation to the property boundary as it is very important that a fire cannot easily spread to neighboring properties.

Full details of the regulations applying to England & Wales are set out in Approved Document B which can be downloaded from the Government’s Planning Portal.

Regulations for Scotland are contained in the Scottish Technical Handbook and the regulations for Northern Ireland can be found in Technical Booklet E.

Fire Protection Solutions for Steel Framed Buildings

There has been a considerable amount of research carried out into the behavior and effect of fire on steel over the past 20 years and fire protection solutions for steel frames are now widely available. Click Report

Hot rolled steel frames can be treated with an intumescent paint Click for info

Cold rolled steel frames and hot rolled counterparts react differently in a fire meaning the product can not be coated in intumescent paint. In order to protect the columns etc on a cold rolled steel structure Fire protection boards are frequently used which can provide a fire resistance of up to 1.5 hours (based on double thickness with staggered joints).

Fire Resistance Classification of Building Walls

Insulated cladding with fire resistant cores have been developed to help the spread of fire in a steel building.

The most common product that is used within the design is a KS1000rw composite cladding Kingspan.

Oxford Leathercraft was a cold rolled project that we carried out using KS1000rw 40mm composite cladding on the side elevations due to close proximity of the neighboring property.

Firth Brothers Developments was a hot rolled project we carried out using the KS1000rw composite cladding on the side elevations due to the close proximity of the neighboring building.

Building walls are required to contain a fire inside a building and are assessed on their ability to meet the following :-

  • Stability – the ability of the wall to remain in place during a fire
  • Integrity – resistance to flame and hot gases
  • Insulation – resistance to heat transmission

If the cladding used in the building walls is able to meet these criteria for 1 hour it is classed as having 1 hour fire resistance.

Class 0 Classification

This is the best possible classification used for wall or ceiling material that does not help the spread of fire and meets tests set out in Building Regulations Approved Document B.

Class 0 – is an additional level of protection for walls or ceilings where limited combustibility is required in high-risk areas, such as escape routes. To comply with Class O materials must have a Class 1 Surface Spread of Flame and low fire propagation index, in accordance with BS 476 Part 6.

Class FAA/SAA Classifications

These classifications are used for material that does not allow fire to penetrate a roof or spread across a roof if burning material falls from an adjacent burning building.  A surface is classed as FAA (flat) or SAA (sloping) if it has no spread of flame and resists fire penetration for at least one hour.

Unprotected Areas

Windows and areas of wall which do not provide fire resistance are classed as unprotected areas.  Building Regulations allow more unprotected areas as the building is located further from the property boundary.

Fire Resistance of the Building Roof

The roof of the building envelope does not generally require fire resistance, however, building owners may be required to include fire resistant panels which conform to Factory Mutual (FM) or Property and Business Protection – Loss Prevention Certification Board (LPCB) standards to obtain insurance cover.

One thought on “Portal Steel Framed Building & Fire Regulations