Line chimney structures and flues with flexible liners

Business Sectors (Suites): Chimney Occupations (Construction)
Developed by: Construction Skills
Approved on: 31 Dec 2022


​This standard is about preparing chimney services and systems, insstalling flexble metallic lining systems, interpreting information, adopting safe, healthy, and environmentally responsible work practices, selecting, and using materials, components, tools, and equipment, in accordance with the work area and the organisational procedures which are equal to or exceed the current statutory and legislative documentation and specificationsThis standard is for people working in the occupational area of Chimney Occupations and can be used by operatives, supervisors and managers

A description of terms in bold font in this National Occupational Standard can be found in the Glossary which should be used as a reference point

Performance criteria

You must be able to:

​Interpretation of information
P1 interpret the information relating to the work and resources to confirm its relevance for the following:
•  documentation and specifications
•  drawings
•  schedules
•  contract information
•  pre-installation surveys
•  risk assessments
•  method statements
Safe work practices
P2 comply with the relevant legislation, official guidance and organisational procedures, to carry out your work and maintain safe, healthy and environmentally responsible work practices relating to the following:
•  methods of work
•  safe use of health and safety control equipment relevant to the           task being undertaken and the working environment
•  safe use of access equipment and working platforms
•  safe use, storage and handling of materials, tools and equipment
•  specific risks to health including mental health
•  specific risks associated with asbestos containing materials
•  specific risks associated with silica dust, mortars and sealants
Selection of resources
P3 select the required quantity and quality of resources for the methods of work:
•  materials, components and fixings
•  tools and equipment
•  access equipment
Minimise the risk of damage
P4 comply with organisational procedures to minimise the risk of damage to the work and surrounding area by:
•  protecting the work and its surrounding area from damage
•  maintaining a safe, clear and tidy work area *
•  disposing of waste in accordance with         current legislation and industry best practice
Meet the contract specification

P5 comply with the contract information to carry out the work efficiently to the required specification by the following:
•  demonstrating work skills to remove, measure, cut, mix, position,        secure and finish
•  assessing suitability and identifying remedial repairs 
•  inspecting, preparing and installing flexible chimney liners to                 working instructions
•  using and maintaining hand and power tools and ancillary                  equipment
Allocated time
P6 complete the work within the estimated, allocated time in accordance with organisational procedures, the programme of work and to meet the needs of other occupations and/or client

Knowledge and Understanding

You need to know and understand:

P1 Interpretation of information

K1 why organisational procedures have been developed, to report and rectify inappropriate information and unsuitable resources, and how they are implemented
K2 the types of information, their source and how they are interpreted in relation to:
•  documentation and specifications
•  drawings
•  schedules
•  contract information
•  pre-installation surveys
•  risk assessments
•  method statements
K3 the range of relevant digital services, tools and systems, and how they are used
K4 the importance of organisational procedures to record, report and solve problems with the information and why it is important to follow them
P2 Safe work practices
K5 information for current legislation and official guidance and how it is applied
K6 the types of fire extinguishers and how and when they are used in relation to water, CO2, foam, powder
K7 how emergencies should be responded to and reported in accordance with organisational authorisation and personal skills in relation to: 
•  fires, spillages and injuries
•  emergencies relating to occupational activities
•  identification and reporting of asbestos containing materials
K8 the organisational security procedures for tools, equipment and personal belongings in relation to:
•  operative 
•  site
•  workplace
•  vehicles
•  company
•  access equipment
•  plant equipment
•  customer
•  the general public
•  other occupations within the workplace
K9 how to report risks and hazards identified by the following:
•  methods of work
•  risk assessment
•  personal assessment
•  manufacturers’ technical information
•  statutory regulations
•  official guidance
•  Control of Substances Hazardous to Health (COSHH)
K10 the accident reporting procedures and who is responsible for making the report
K11 why, when and how health and safety control equipment identified by the principles of prevention should be used in relation to:
•  collective protective measures
•  personal protective equipment (PPE)
•  respiratory protective equipment (RPE)
•  local exhaust ventilation (LEV)
K12 how to comply with environmentally responsible work practices to meet current legislation and official guidance when dealing with potential accidents, health hazards and the environment in relation to working:
•  in the workplace
•  below ground level
•  in confined spaces
•  at height
•  with tools and equipment
•  with materials and substances
•  whilst moving and storing materials by manual handling and             mechanical lifting
P3 Selection of resources
K13 why the characteristics, quality, uses, sustainability, limitations and defects associated with the resources are important and how defects should be reported and rectified
K14 the organisational procedures to select resources, why they have been developed and how they are used
K15 how to confirm the resources and materials conform with the specification
K16 how the resources should be used and how any problems associated with the resources are reported in relation to:
•  flexible liners
•  backfill
•  insulation materials
•  sands, mortars, cements and compounds
•  fixings and fittings
•  support components
•  closure plates
•  adaptors
• hand and power tools and  equipment
K17 how to identify the hazards associated with the resources and methods of work and how they are overcome
K18 how to calculate quantity, length and wastage 
P4 Minimise the risk of damageK19 how to protect work and its surrounding area from damage and the purpose of protection from general workplace activities, other occupations and adverse weather conditions and how to minimise damage to existing building fabric
K20 why and how the disposal of waste must be carried out safely in accordance with the following
•  environmental responsibilities
•  organisational procedures
•  manufacturers’ information
•  statutory regulations
•  official guidance
K21 why it is important to maintain a safe, clear and tidy work area
P5 Meet the contract specification*
K22 how the methods of work, to meet the specification, are carried out and how problems are identified and reported by the application of knowledge for safe, healthy and environmentally responsible work practices, procedures and skills relating to the method and area of work in relation to the following:
•  how and why it is important to inspect and prepare chimney              structures and identify remedial work
•  how to install flexible metallic liners for designated fuel types 
•  how to provide permanent and temporary support
•  why it is important to provide permanent and temporary support
•  why it is important to select the correct flue diameter
•  why it is important that the flue terminates in an appropriate               position
•  the importance of flue designation and how to check that the               flue is compatible with the appliance and its intended use
•  how to provide access for inspection and maintenance
•  how to remove and replace chimney pots
•  the relevance of an assessment of significance and how to                   recognise specific requirements for structures of special interest,        traditional construction, hard-to-treat buildings and historical            significance
•  how to work safely with, around and in close proximity to plant          and machinery
•  how to use hand and power tools and equipment
•  how to work at height using access equipment
•  how and why operative care and maintenance of hand and power      tools and equipment is carried out
K23 the importance of team-work and communication, organisational procedures with respect to site behaviours, and how to respond to inappropriate site behaviours
K24 the needs of other occupations associated with lining chimney structures and flues with flexible liners
P6 Allocated time
K25 the programme of work to be carried out including the estimated and allocated time and why deadlines should be kept
K26 the types of progress charts, timetables and estimated times and the organisational procedures for reporting circumstances which will affect the work programme


Scope Performance

Scope Knowledge





Organisational procedures
Insurances – public, product and employers liability, professional indemnity
Company documents
contract for the work, safety management plan, Construction Design and Management regulations, environmental policy, complaints procedure, information privacy and security policy, management structure
Work area
The area where the equipment will be installed and all areas affected by the work extending to topographical features and meteorological conditions
Services and systems
Chimney and flue systems, appliances, ventilation systems and appropriate utilities
Documentation and specifications
Manufacturers’ instructions for all equipment that forms part of the work
architect’s plans and site-specific documentation
local building rules and regulations
Party Wall legislation
Clean Air Act
Environment Act
Smoke Control Zones
Permitted Development
Conservation Areas
Heritage status
Areas of Outstanding Natural Beauty
Sites of Special Scientific Interest
specific requirements of insurance underwriters
Building regulations in England and Wales, particularly ADJ but also ADA, ADB, ADF, ADL and AD7
Building Standards Technical Handbook in Scotland
Technical Booklets in Northern Ireland, particularly B, D, E, F1, F2, K and L
BSEN’s particularly 8303, 15287, 1856, 16510, 1251, 3376, 4834, 12815, 13229, 13240, 15250
Note: Technical and BSEN documents may be withdrawn or superseded during review programmes, it is therefore important to check the currency and validity of all such documents to ensure the correct version is being referenced.
Solid fuel burning appliances up to 50kW output including but not limited to the following:
•  open fires
•  free standing room heaters
•  inset room heaters
•  free standing cookers
•  independent boilers
•  slow heat release stoves

Links To Other NOS

External Links

Version Number


Indicative Review Date

31 Dec 2027





Originating Organisation


Original URN


Relevant Occupations

Construction and Building Trades nec

SOC Code



Chimneys; Flues; Metallic-lining; Flue-systems; Chimney-pots