Regulation 4 ‘Duty to Manage’ was introduced in the Control of Asbestos at Work Regulations 2002 and has been law since May 2004. The regulations have recently been replaced by the Control of Asbestos Regulations 2006 effective from 13th November 2006.

This regulation places a duty on a defined “Duty Holder” to manage the risk from asbestos in non-domestic premises. It is not a duty to survey asbestos or a duty to remove asbestos but a duty to MANAGE asbestos. There have been well published campaigns and road shows from the HSE and campaign partners since the 2002 regulations and the latest is the “Don’t take the Gamble with Asbestos Campaign”. Full details are on the HSE website

If you are responsible for maintenance and repair activities for non-domestic buildings or common areas in domestic buildings, through a contract, tenancy agreement or through ownership then you are a “Duty Holder” and you have the responsibility to manage asbestos. However, 3 years down the line since the May 2004 implementation (there was also an 18 month lead-in period prior to that) many “Duty Holders” have still not fully taken on board this legislation requirement. Some have done nothing, some have some form of survey undertaken but how many have adequate and effective Management Plans? Are the systems in place sufficient and robust enough to prevent employees and tradesmen from being inadvertently exposed to asbestos? Are the lines of communication, assignment of roles and responsibilities, easy availability and understanding of asbestos data, permits to work etc in place, working and sufficient to prevent inadvertent exposure? Is the information available regularly reviewed and updated? Have re-inspections been carried out and fresh risk assessments undertaken to detail changes in condition or usage since the last survey? HSE certainly expects all this to be in place.

The extent of full compliance is unclear and bearing in mind the size of the problem – more than 2 million non-domestic properties and with 4000 asbestos related deaths annually and rising – HSE will shortly embark on a programme of compliance checks and a review of the “Duty to Manage”. HSE is also concerned that the attitude of “Duty Holders” may be flippant to asbestos risks and that they may not recognise or understand that managing the asbestos risk is a key health & safety concern. So expect a visit from your friendly HSE Inspector shortly.

System building

Particular types of buildings or properties because of their age and type of construction may be challenging to the “Duty Holder” even if in apparent compliance with Regulation 4 of CAR 2006. Such buildings include “System Builds” which were so common in the boom building periods of the 1960s and 1970s but trace their history and prototypes to immediate post WW2. New and novel construction methods were being introduced to industrialise the building process especially in the public sector and various forms of factory prefabricated and site erected structural components were being introduced.

Proprietary lightweight prefabricated systems included:

  • CLASP – 1957 to 2005, local authority consortium, steel frame
  • SCOLA – 1962 to 1990, local authority consortium, steel frame, similar to CLASP
  • Hills – 1944 to 1963, privately owned, post-war forerunner to CLASP and SCOLA
  • Method – 1963 to 1988, South West area, similar aspects to CLASP
  • SEAC – to late 1970s, South East area, similar aspects to CLASP
  • Vic Hallam – 1960s and 70s, privately owned, timber framed

also MACE, ONWARD and A75 systems. Heavyweight prefabricated systems, essentially all in pre-cast concrete, include Reema, Bison Wall Frame, Intergrid, G80 and Laing (Sectra, Laingspan and Laingwall) systems.

Essential to the building design, especially to the steel and timber framed structures, is adequate fire protection and asbestos containing materials were certainly used for this purpose. The peak years of System Building in the 1960s and 70s also coincided with the peak years for asbestos imports and manufacture of asbestos containing materials so it is of no surprise to find ACMs used in a variety of components and situations.

In terms of asbestos CLASP buildings are the best documented. CLASP and its successor (Scape System Build Ltd from 2005) have published a CLASP Asbestos Awareness Handbook since at least 1995 and this is available on-line ( Recently potential problems with exposure to asbestos have arisen in certain CLASP properties and this can be presumed to be present in others and possibly in other system builds if the right circumstances take place.

What is CLASP?

CLASP stands for the Consortium of Local Authorities Special Programme and was formed as a group of mainly Local Authorities in 1957 in response to the overwhelming demand for new educational accommodation which the building industry was incapable of meeting through traditional construction methods. Its main purpose was to develop a method of building which did not rely on traditional building skills or wet trades and to provide a fast, efficient and cost effective method of meeting the demand for permanent education buildings. It became known as the “CLASP Building System”. It has been known since 2005 as Scape System Build Ltd and is a Local Authority controlled company whose shareholders are Derby City, Derbyshire County, Gateshead, Nottingham City, Nottinghamshire County and Warwickshire County Councils and is the trading company for the CLASP Consortium.

CLASP was used mainly for schools but also used for hospitals, computer installations, universities, fire stations, ambulance stations and offices. It was mainly used in the UK but is also found in Europe, Venezuela, Algeria and Hungary. Scape reckon that there are 4000 CLASP buildings worldwide with 3500 of these in the UK. HSE have recorded 3134 CLASP contracts in the UK with 1400 built as schools. Current owners include

Local Authorities, Government, Education (Public and Private), Police Authorities, Fire Departments, MOD, Health Boards, Railways and Universities.

Very few CLASP buildings were actually designed by the Consortium. Rather design was by Private and Public Sector Architects using standard details, specifications and structural system provided by CLASP. The system was in use from 1957 onwards but forerunners go back to 1944. There was continual development over the years with each significant change denoted by a new Mark. Pilot projects were undertaken in Nottinghamshire, Coventry and Leicester in 1956 – 1958 and can be regarded as Mark 1 although was never used officially. Thereafter the designated marks were as follows:

  • Mark 2 1957 – 1960
  • Mark 3 1959 – 1962
  • Mark 3b 1962 – 1966
  • Mark 4 1966 – 1968
  • Mark 4b 1968 – 1971
  • Mark 5 1970 – 1984
  • Mark 6 1984 on

The basis of the CLASP system is a steel frame (of columns, cross-bracing and ceiling/floor trusses) planned on a structural grid and is governed by a basic module dimension. The module dimension and floor to ceiling heights changed between imperial and metric units in 1970 (Mark 5). Single storey blocks were common but the system could also be used for 2 to 4 storey blocks. The system relied on a mixture of factory assembled and site assembled elements. Differences between Marks related to the main steelwork design (3 to 3b, 4 to 4b) and in the arrangement, materials and components of external elements (windows, cladding and eaves) and internal elements (ceilings and partitions). Fire protection was necessary especially on ground floors. No asbestos products were specified as part of the standard construction since 1980 (mid Mark 5) but could have been built-in on site.

The CLASP Asbestos Awareness Handbook lists many ACMs known to have been part of the CLASP Standard Details. These vary with Mark and include asbestos insulation board, asbestos cement, woven cloth and standard building features such as vinyl floor tiles, stair-treads, stair nosings and boiler lagging. Other ACMs are listed as possible and include other standard building

ACM Trade Name Location/Use Mark
Insulation board Asbestolux Suspended ceilings, porches, recessed areas, kitchens, fire protection 2 to 5 *
Insulation board Asbestolux Heater cabinets 2 to 4 *
Insulation board Asbestolux Wall linings to stud frames 2 *
Insulation board Asbestolux Backings to pressed metal sheet casings to columns 3 to 4b *
Insulation board Asbestolux Backings to window infill panels 3 *
Insulation board Asbestolux Tolerance packs for metal casings to columns 5 *
Insulation board Asbestolux Lining to window board 3 to 5 *
Insulation board Asbestolux Packing pieces between ceilings and stair support beams 5 *
Insulation board Marinite Glazing beads to fire doors 2 to 5 *
Cement TAC Plinth upstand below concrete cladding 5 *
Cement TAC Gutter unit 2 *
Cement Turners Troughed boiler house roof 2 to 5 *
Woven cloth Fortex Fire stops above suspended ceiling 5 *
Woven cloth Fortex Bedding strips between steel beams and pc concrete floor decks 5 *
Asbestos wood TAC Moulded casing to columns 4 *
Vinyl floor tiles Dunlop Semtex etc Floor tiles 2 to 5 *
Stair-tread Ferodo Stair-tread 4 to 5 *
Stair nosings Ferodo Stair nosings 3 to 5 *
Insulation lagging Andrews Weatherfoil Boiler lagging 2 to 5 *
Insulation board Asbestolux Beneath sinks and worktops 2 to 5 O
Cement TAC Cycle sheds, external store roofs, boiler room linings 2 to 5 O
Cement TAC Moulded goods – tanks, rainwater goods, flue pipes 2 to 5 O
Cement TAC Soffits and fascias 2 to 5 O
Lagging Various Insulation to pipework, boilers etc 2 to 5 O
Roofing felt Andersons, Briggs – Amasco Roofing 2 to 5 O
Sprayed coating Various Thermal and acoustic insulation, condensation and fire control 2 to 5 O
Insulation board Various Fire, thermal, acoustic insulation. Moisture movement. General building board. Ducts, fire-breaks, infill panels, partitions, ceiling tiles, roof underlays, wall linings, bath panels, canopy and porch linings. 2 to 5 O
Insulation board Various Cores and linings to composite products 2 to 5 O
Compressed boards Various Partitioning, shuttering, decorative panels, facings, soffits and linings 2 to 5 O
Cement tiles and slates Various Cladding, decking and roofing 2 to 5 O

ACMs that may be included in any construction of that year of build – roofing felt, laggings etc. In particular asbestos insulation board is well used in all Marks. The table summaries some of the main uses of ACMs in CLASP buildings:

Problem with CLASP buildings

In July 2006, during a programme of asbestos removal work, the Rhondda Cynon Taf local authority in Wales experienced unexplained disturbed air monitoring failures in a CLASP school which had a potential for significant asbestos exposure. The problem was found to be related to asbestos insulation board linings and debris within column casings in conjunction with a poor seal to the column casings. By mid September 2006 the problem had been reported to HSE and on 12 October 2006 Scape issued a “FORMAL NOTICE – Release of Asbestos Fibres in CLASP Buildings” to CLASP building owners. By mid to late October 2006 Advisory Notes to all Directors of Education etc and a Joint Message from HSE/COSLA in Scotland were issued to the Education sector. On 3 November 2006 IOSH published “Risk of asbestos exposure in CLASP schools” on its internet notice board to the wider Health & Safety community.

By December 2006 the Asbestos in Schools CLASP Working Group was set up and met on 13/12/06 and subsequently on 26/02/07 with representative of HSE, Local Authorities, COSLA, Scape and others. The Health & Safety Laboratory (HSL) had been commissioned to carry out research and this was published as “Summary of fibre concentrations in CLASP construction schools containing asbestos” at the start April 2007. The Working Group through HSE quickly published guidance – “Asbestos in CLASP and other System Buildings: Control of Asbestos Regulations 2006: Guidance for duty holders produced by the HSE Asbestos in Schools ‘CLASP’ Working Group” – in late April 2007.

The metal casing to columns is formed of 2 U-shaped sections which encase the columns. There is therefore a vertical joint on the front and back faces where the 2 sections meet. The casing may have an insulation board lining glued to the inside face of the casing. The column itself may also have an insulation board lining attached to the column and insulation board packers or spacers may also have been used in the space between the column and casing. The casing normally extends into the ceiling void above the suspended ceiling system but does not normally extend full height to roof level. Any column lining and/or packers or spacers may thus be visible in the ceiling void.

Circumstances for fibre release

There are three parameters for fibre release associated with column casings into a room or area:

  • Damaged insulation board lining, packers, spacers or debris within the column casing; the damage having occurred due to earlier maintenance, or associated with window installation work, or by being built in during construction
  • Significant impact on the casings or vibration from closure of adjacent windows or doors to release asbestos fibres into the casing air space
  • Poor seal between the casing halves or at the casing – wall or casing – skirting joints to although asbestos fibres to be released into the room

If one or more of the above parameters is absent then no asbestos fibres should escape into the room or area. Other factors such as original construction AIB waste in wall cavities and column casings, column casings cut for cabling routes and disturbance during window replacement work will also play a part.

Actions required by duty holders

The HSE Working Group recommends the following actions:


  • Identification of CLASP buildings
  • Visually inspect full length of column casings for cracks, gaps, presence of screws, dents, damage and movement
  • Visually inspect top and bottom of casings
  • Check for signs of maintenance work since installation e.g. drilled holes, attached fixtures
  • Seal all gaps in the joints between column casing to casing, column casing to skirting and column casing to walls using silicone based sealant and UPVC finishing strips if required
  • Visual check if sealing is effective
  • Re-secure casings if lose – fixings normally at top and bottom of column
  • Note and record actions taken


  • Inspection of ceiling void and any resulting actions if asbestos present
  • Prevent teaching, janitorial and other staff from lifting ceiling tiles
  • Training
  • Procedures for any further work that will disturb column casings

All work requires to be undertaken in accordance with CAR 2006 and “Duty Holders” have a Duty to Manage the CLASP problem under Regulation 4. HSE will shortly be writing to all known owners of CLASP buildings for details of their asbestos management arrangements under Regulation 4 Duty to Manage.

Further problems with CLASP buildings

Nationwide school modernisation programs are underway and CLASP buildings are scheduled for major refurbishment or demolition now or in the near future over much of the UK. Indeed many CLASP properties have already been demolished. Asbestos matters will play a large part in any planned refurbishment or demolition due to the potential for additional ACMs especially asbestos insulation board hidden within column casings, wall voids and ceiling voids, woven blanket fire stops and bedding strips and the ubiquitous use of insulation board as a general purpose building board. This will impact on the Type 3 Intrusive survey prior to refurbishment or demolition and it is recommended that asbestos surveyors have training specific to CLASP and other System Build buildings to ensure that the Type 3 survey is effective in finding and quantifying all ACMs. CDM Co-ordinators will also require to have knowledge of System Builds and the potential Health & Safety difficulties that may ensue as will Designers and Quantity Surveyors especially when compiling Bills of Quantity for asbestos removal.

The difficulties mainly relate to the hidden ACMs. Wall voids may contain asbestos (AIB) insulation board spacers or packers between wall and columns plus AIB debris in the void. Support tracking for walls at floor level may have AIB packers or hide AIB debris. Cross-bracings may be clad in AIB or wrapped in woven blankets. Columns may have metal casings with AIB linings, AIB packers/spacers and AIB debris in the void. The column itself with or without casings may have 1 or more sides with AIB board glued to the metal. Woven blanket may be used as fire stops in ceiling voids. AIB may be used in any situation that requires a liner, packer, spacer, batten, board or plank and if this is the situation then debris is expected to be present in any adjacent void. Woven bedding strips in Mark 5 buildings between concrete floor decks and support beams will be glued to the concrete.

A further difficulty is the variability of it all. Some buildings have no ACMs associated with columns. Others vary from room to room, floor to floor or even between adjacent columns. Others have linings, spacers or packers of plasterboard or timber or mixtures of AIB, plasterboard and timber. False columns (i.e. casings only without structural columns) may also be present. This means that any inspection or survey has to be thorough enough to overcome all the variabilities and any decision made on that information must be interpreted in light of the inherent variations.

Published: 10th Jul 2007 in Health and Safety International