Apply liquid membrane systems Legacy

Business Sectors (Suites): Waterproof Membrane Roofing Systems
Developed by: Construction Skills
Approved on: 17 Mar 2023


This standard is about applying liquid waterproofing systems on new and re-roofing contracts including liquid preparation and the base and finishing coats

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This standard will also involve interpreting information, adopting safe, healthy and environmentally responsible work practices, selecting and using materials, components, tools and equipment, in accordance with organisational requirements which are equal to or exceed current statutory and legislative requirements

This standard is for people working in the occupational area of waterproof membrane roofing systems and can be used by operatives, supervisors and managers

Performance criteria

You must be able to:

**P1 Interpretation of information**
interpret the following information to confirm its relevance to the work: 
method statements
risk assessments
permits to work
manufacturers’ information
electronic data
oral and written procedures
current regulations
site inductions
**P2 Safe work practices**
comply with the relevant legislation and official guidance to carry out the work and maintain safe and healthy work practices relating to the following:
methods of work
safe use of health and safety control equipment
safe use of access equipment
safe use, storage, handling and distribution of materials, tools and equipment
specific risks to health
specific risks associated with asbestos containing materials
specific risk associated with respirable crystalline silica (RCS)
**P3 Selection of resources**
select the required quantity and quality of the following resources for the methods of work:
components and fixings
tools and ancillary equipment
**P4 Minimise the risk of damage**
comply with site specific 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, clean and tidy work area 
disposing of waste in accordance with current legislation
**P5 Meet the contract specification**
comply with the contract information to apply single ply membrane roofing systems efficiently to the required specification by:
demonstrating work skills to:
- measure
- cut

- mark out
- fit
- position 
- secure

use and maintain hand tools, power tools and ancillary equipment
install air and vapour control layers (warm and cold roofs) and insulation

apply two of the following single ply membrane roofing systems 

- adhered
- ballasted
- mechanically fixed 
to given working instructions, relating to the following:
- protection layers
- separation layers
- water control membranes (inverted roofs only)
- edges and upstands
- penetrations, pipes and vents
- perimeters, gutters and rainwater outlets

P6 Allocated time
complete the work within the estimated, allocated time in accordance with the organisational procedures 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 and how they are implemented

K2 The following types of information, their source and how they are interpreted:
method statements
risk assessments
permits to work
manufacturers’ information
electronic data
oral and written procedures
current legislation 
site inductions

K3      the importance of reporting and rectifying inappropriate information 

K4 the range of relevant digital services, tools and systems, and how they are used

P2 Safe work practices
K5 information for relevant, current legislation and official guidance and how it is applied

K6 the following types of fire extinguishers and how and when they are used: 

K7 how emergencies should be responded to in accordance with organisational authorisation and personal skills in relation to: 
fires, spillages, injuries
emergencies relating to occupational activities
identification of and reporting of asbestos containing materials
identification of silica

K8 the organisational security procedures for tools, equipment and personal belongings in relation to:
the general public

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

K13 the organisational procedure when dealing with potential accidents, health hazards and the environmental impact whilst working:
below ground level
in confined spaces
at height
at proximity to fragile roofs
with tools and equipment
with materials and substances
moving and storing materials by manual handling and mechanical lifting

P3 Selection of resources
K14 why the characteristics, quality, uses, sustainability, limitations and defects associated with the resources are important and how defects should be rectified

K15 the organisational procedures to select resources, why they have been developed and how they are used

K16 how to confirm the resources and materials conform with the specification and how any problems associated with the resources are reported

K17 how the following resources should be used and how any problems associated with the resources are reported:
single pack
multi pack and heated liquid components
air and vapour control layers (AVCL)
preparation coats
base coats
pedestrian surfacing
protection layers
separating layers
movement joints
associated materials
fixings and fittings
spray equipment
hand and/or power tools 
ancillary equipment

K18 how to identify the hazards associated with the resources and methods of work and how they are overcome

K19 methods of calculating the quantity length and wastage associated with the method and procedure to apply liquid membrane systems

P4 Minimise the risk of damage
K20 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 

K21 how to minimise the damage to existing building fabric

K22 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

K23 why it is important to maintain a safe, clear and tidy work area 

P5 Meet the contract specification
K24 how to meet the contract specification in relation to the following:
install air and vapour control layers (AVCL)
install insulation materials
prepare single pack, multi pack and heated liquid components by mixing and heating techniques
apply liquid membrane systems with control of application thickness by brush, roller, trowel, squeegee and spray application
apply multiple coats including base and finish coats, implementing applicable control and constraints
install reinforcement systems utilising both fleece and glass fibre
install vertical upstands, including internal/external corners, joints and junctions, straight and curved and incorporating changes of plane and treatment of internal angles
install terminations (cover flashing, external trim, termination bar, junctions to other materials)
install to perimeters (eaves, mono ridge, verges and drips), outlets (spigot, sump parapet, overflow), pipes, structural penetrations (vertical, pitched and horizontal, including plinths and hand rolled collars), safety systems, internal gutters, stop ends, rooflights, hips, valleys and pedestrian finishes, incorporating vertical surfaces
take account of the effects of temperature and weather conditions
implement snagging procedures and appropriate remedial work, including preparation for test procedures
the relevance of an assessment of significance
how to recognise specific requirements for structures of special interest, traditional construction, hard-to-treat buildings and historical significance
work with, around and in close proximity to plant and machinery
safely work at height using access and fall prevention equipment
how to use all hand and power tools and ancillary equipment
how and why operative care and maintenance of all hand, power tools and ancillary equipment is carried out

K25 the importance of teamwork and communication

K26 the importance of mental health awareness and wellbeing 

K27 the importance of applying Fairness, Inclusion and Respect (FIR) when dealing with others

K28 the needs of other occupations associated with apply liquid membrane systems 

P6 Allocated time
K29 the programme of work to be carried out including the estimated and allocated time and why deadlines should be kept

K30 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





Links To Other NOS

External Links

Version Number


Indicative Review Date

17 Mar 2028





Originating Organisation


Original URN


Relevant Occupations

Roof Tilers and Slaters, Roofers

SOC Code



Waterproofing; Multiple coats; Base-coats; Top-coats; Reinforcements; Insulation; Fleece; Glass fibre; Air and Vapour control layer (AVCL); Roofing