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ASSESSMENT CRITERIA
ACTMAP 1 PART 2: REQUIREMENTS
REQUIREMENTS APPLICABLE TO ALL ROOF WATERPROOFING SYSTEMS
Safety
Wind loads. There must not be any risk of pull-off or mechanical failure of the waterproofing system and its support and any associated protection, as a result of repeated suction forces to which it is subjected by gusts of wind.
The suction effects which have to be taken into account are specified in SABS 0160, General procedures and loadings to be adopted for the design of buildings. They vary according to region, location, height, shape and orientation of buildings.
Behaviour in fire. The complete roof system must satisfy the fire requirements of the current National Building Regulations. The behaviour in fire of products used in any particular waterproofing system depends on the waterproofing medium (combustible or non-combustible), the substrate on which the system is laid (combustible or non-combustible), the protection given to the waterproofing medium and the slope of the roof. Minimum safety distances, as given in the deemed-to-satisfy rules of SABS 0400, The application of the National Building Regulations, are applicable in the case of combustible roof covering materials, with certain exceptions. (The spread of flame, ease of ignition, smoke development and toxic gases emitted in a fire must also be taken into account.)
Health. The suitability of rainwater runoff from the roof for drinking purposes must be assessed.
Fitness for use as a waterproof covering
Watertightness. The waterproofing system must prevent water from entering the substrate.
Staining. The waterproofing materials should not contain leachable or reactive components which would stain the outside of the building if runoff should come into contact with it.
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Preservation of qualities
General
The principal factors that are likely to influence the performance of the waterproofing and particularly the conservation of its waterproofing properties are:
- environmental factors: wind, temperature, ultra violet (UV) radiation, water
- chemical factors: atmospheric gases and chemical agents
- biological factors: bacteria, lichens, fungi, etc
- movements of the support: deflections, shrinkage, cracking
- user loads: indentation, wear
- the protection
Products used in waterproofing systems that can be easily repaired or replaced must preserve their properties satisfactorily for an assessed life of at least 10 years with only normal maintenance which may include periodic renovation. Products used in waterproofing systems that are difficult to replace must have an assessed life of at least 20 years.
Normal maintenance means the procedures recommended by the manufacturer (which must be specified in the Agrément Certificate) but also involves removal of leaves, the checking of roof drainage and, if necessary, the replacement and leveling of gravel or mineral chippings.
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Environmental factors
Effect of wind. The wind waterproofing system including any protection must resist without deterioration the effect of occasional extreme wind gusts and the fatigue effect of recurrent winds of lower speed. The action can either occur as a direct pull-off force or as a peel force. The effects to be considered are:
- for the system:
- loss of adhesion between the system and the support
- loss of adhesion at the joints between sheets, or between layers of the waterproofing material
- loss or movement of the protective layer.
- for the materials:
- delamination of composite materials.
Effect of temperature. The waterproofing system must resist without deterioration temperatures from –10 °C to +80 °C and rapid reversals of temperature of the order of 60 °C. Account must be taken of:
- the effect of temperature on the support of the waterproofing and its effect on the waterproofing system
- any protective finish and its effect on the maximum temperature and on temperature reversal
- the envisaged life of, and the effect of dirt accumulation on thin protective finishes.
The effects to be considered are:
- thermal movements of the waterproofing material in relation to joints between flexible manufactured sheets, roof details and bond to substrate
- thermal movements of the substrate in relation to possible splitting of the waterproofing material
- deterioration of the waterproofing material as a result of ageing.
Effect of UV radiation. The waterproofing material together with its protection must resist the action of UV radiation without deterioration of its essential properties.
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Distinction may be made between:
- exposed materials which must have an intrinsic resistance to UV radiation
- materials which are protected from UV radiation by a supplementary covering.
The effects to be considered are:
- deterioration in the properties of the materials
- changes in surface appearance.
Water. The waterproofing system must resist the action of precipitation (rain, hail and snow) and the effects of running or standing water on its top surface (including the action of ice formation), or being present at the undersurface (condensation).
Hot water or steam must not be discharged directly onto a waterproofing system.
The effects to be considered are:
- changes in the properties of the waterproofing materials
- moisture movements of the support in relation to the waterproofing system
- bond to the support and between layers of the waterproofing materials
- surface erosion
- mechanical stresses created by ice formation or by solids carried by the water
- mechanical damage (puncturing) by hailstones.
Chemical factors. Materials used in waterproofing systems should be capable of resisting chemical attack from:
- common atmospheric gases such as 02, 03, C02, S02, H2S and saline atmospheres
- industrial or other pollutants that may be specified.
Biological factors. The material used must not support the growth of bacteria, lichens, fungi, etc or be liable to damage by insects, birds, small rodents, etc.
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Effect of movement. The design of the total roof and the properties of the waterproofing system must be such that the system can withstand the normal movements which may be expected of its direct support or transmitted to it from other parts of the building. The movements to be considered are:
- Deflections under load. The recommended deflection limits of the structural components are defined in SABS 0160 and in the relevant code of the material concerned. In some instances the waterproofing system may impose its own deflection limitations.
- Irreversible movements. Shrinkage and/or deformability of the support which may cause monolithic supports to crack or joints in composite supports to open.
- Reversible movements. Moisture and thermal movements of the support. The frequency and magnitude of the movements have to be considered.
Where a waterproofing system is based on flexible sheets, the effect of any movement will largely depend on the method of fixing the sheets.
The effect of any given amplitude and frequency of movement will be greatest for fully bonded systems and the effect will decrease through partially bonded to loose laid systems.
User loads. The waterproofing system, its support and its protection if any, must be capable of supporting normal user loads. Normal specified loads should not cause any punctures or undue permanent deformation in the waterproofing layer.
Account must be taken of the softening of the waterproofing material at elevated temperatures and embrittlement at low temperatures and the possible deformation of the support.
Two types of loading are considered: static loads and impact loads. Static loads are loads applied for indefinite periods (ie plant), or for one or two days (eg maintenance equipment, ladders), and transient loads created by pedestrian traffic. Impact loads result from dropping tools, etc.
The risk of mechanical damage due to static or impact loads and the level of loading will depend on the accessibility of the roof, and the type and frequency of the traffic.
Compatibility. The materials used in the waterproofing system must be compatible one with another, with the other parts of the roof system (in particular the waterproofing support and the protection) and with those materials normally used in building construction with which it may be in direct contact or in indirect contact, via water-borne solvation products.
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Compatibility problems may arise during the installation process (eg the support layer may be softened by the solvents or by the temperature at which the adhesive is applied).
Incompatible materials may affect long term performance, for example plasticiser migration from the waterproofing materials into the adhesive.
Protection. Any gravel or other protective coverings (eg paving slabs, paving bricks, hollow blocks, etc) applied to or placed on the upper surface of the waterproofing system must not cause any punctures or excessive deformation in the waterproofing layer during application or when the roof is in use.
Maintenance.In the event of the waterproofing system being damaged (eg unforeseen building movements, or by accident), it is essential that the system can be repaired effectively, despite ageing of the materials.
REQUIREMENTS RELATING TO INSTALLATION ON SITE
General requirement
Detailed instructions for installing the waterproofing system must be provided.
The installation procedure must be such that it can be carried out in a satisfactory manner by roofing contractors.
The instructions for detailing to cope with jointing, internal and external angles, upstands including vertical flashings at junctions with walls, parapets, etc, verges, gutters, gullies, rainwater outlets, expansion joints, vent pipes, etc must be in accordance with good waterproofing practice and compatible with normal building site conditions.
Climatic conditions affecting the materials. The materials must be able to be installed under normal climatic conditions for external construction work in South Africa.
In the case of flexible sheet materials, interruption of the installation process (eg by sudden rain storms) must not be adversely affected to the extent that would impair its waterproofing and durability properties. The system must be able to withstand the normal changes in climatic conditions which may occur within a few hours of installation.
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Where sudden rain storms occur during the application of liquid-applied systems, or before the finished system has cured, the waterproofing must be removed and the process repeated.
Conditions affecting the support. The system must be able to be installed on support materials at the ambient humidity conditions.
Detailed information must be given of the system’s requirements with regard to the planeness, irregularities, etc of the surface of the support.
Requirements for the installation of sheet material or pre-assembled sheets
Resistance to tearing. The tear strength must be such that the material is not easily damaged during handling under normal conditions.
Handling characteristics at low temperature. Materials that cannot readily be heated without risk must be sufficiently flexible at the lowest temperature specified as being acceptable for the roofing materials, so that they do not crack or split when roofing details are being formed.
Impact damage at low temperature. The lowest temperature must be specified at which the material does not shatter or show more than superficial damage when subjected to impacts likely to occur during handling and installation.
Unrolling at low temperature. When tested as specified, the material should be able to be unrolled easily and without damage at 0 °C.
Requirements for in situ liquid-applied membranes, and for primers and adhesives used with sheet materials on site
General. Only primers and adhesives which are recommended by the manufacturer for a specific waterproofing membrane or system may be used.
Shelf life. The maximum shelf life and conditions of storage must be clearly marked on the containers. If a material is adversely affected by exposure to high or low temperature conditions, this must be clearly indicated on the containers, and the highest or lowest temperatures that the material can withstand.
Drying time. The drying time and lowest temperature at which primers and other materials may be applied on site, must be clearly marked on the containers and a drying time of less than 24 hours must be achieved at the lowest temperature.
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Setting time. The setting times at the lowest and highest temperatures for adhesives and other materials that are applied on site must be clearly marked on the containers. A setting of less than 24 hours is required at the lowest temperatures, while setting times at the highest temperature should not be so short that proper adhesion of subsequent layers cannot be assured.
Softening. Adhesives for sheet waterproofing and the materials used in in situ liquid-applied systems, must not cause softening and/or damage to the supporting layer due to the effect of solvents or the temperature at which the materials are applied.
Water sensitivity. The properties of primers, adhesives and other materials and their drying or curing time must not be adversely affected by the ambient humidity of the support.
Requirements for making joints on site (flexible sheet materials)
The reliability of joints is particularly important for single layer roofing systems.
Failure often occurs where there are discontinuities in the joint sealing; it is therefore essential to comply with the requirements set out below.
Jointing system. Detailed instructions on the methods of jointing must be provided by the applicant, including any limitations that apply.
Sensitivity to climatic conditions. The maximum and minimum temperatures and humidity levels which the joints withstand must be specified.
Condition of the support. The instructions for making joints on site should specify that at the joints between roofing sheets, the support must have a smooth surface, free from irregularities that might reduce or prevent the bonding and consolidation of the joint.
Overlap of flexible roofing sheets. The minimum width of overlap of roofing sheets must be specified.
Workability of adhesives (for bonded joints). The temperature extremes which can be tolerated and the pot life of the adhesives and the length of time the pot may be left open, must be indicated by the manufacturer.
Compatibility of jointing materials with the support. Any special measures that are needed to prevent contact between the jointing materials and the support where these are incompatible, must be specified.
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QUALITY CONTROL
Products used in roof waterproofing systems are awarded Agrément certificates only if the manufacturer applies a system of quality management which is acceptable to the Board of Agrément South Africa.
A requirement for certification by Agrément South Africa is that the certificate holder has a simple, approved quality management system in place. This system must be based on the recommendations of the ISO 9000 series.
The system is required to ensure that good quality materials and satisfactory standards of design, manufacture and, where appropriate, erection, are consistently maintained within defined parameters.
The quality assurance system is an aid to continuity of operations which helps eliminate unacceptable changes that might occur as a result in changes in personnel.
Guidelines for the preparation of a a quality management system have been prepared to help certificate holders and applicants to prepare and implement acceptable quality schemes for their products.
The quality document must deal separately with the procedures for
- the manufacturing process and
- the transportation and erection or installation process.
Surveillance inspections
Periodic inspections of the factory are carried out on behalf of the Board in the course of the evaluation and during the period of validity of the certificate to monitor compliance with the conditions of certification.
Identification symbol
Agrément certificated roof waterproofing products must be identified with the appropriate symbol in accordance with the requirements of the Agrément Board.
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CONTENTS OF THE AGREMENT CERTIFICATE
In addition to providing a technical assessment of the subject and indicating how it relates to the National Building Regulations, the Agrément certificate will provide the following information.
Intended use or purpose
This will be defined as a function of:
- slope
- accessibility
- presence or otherwise of protection
- compatible supports (eg concrete and similar, timber and similar, insulation not acting as support).
Description
Sheet waterproofing
Manufactured sheets (waterproofing sheets). The following information will be given:
- type
- presentation: length, width, thickness and mass of roll
- description of build-up of sheet
- chemical composition of components, type and mass of reinforcement, coating mass, etc
- specified properties as determined during assessment
- other properties
Other materials (eg adhesives, screeds, other sheets) used with the sheets will be described according to:
- type
- general identification properties
- In situ liquid-applied systems
- The following information will be given:
- presentation (packaging) of the system
- chemical composition of components, type and mass of reinforcement, volume of liquid(s) applied per square metre
- specified properties
- other properties
Brief description of manufacturing process
Brief list of main quality controls applied in the course of manufacture
Storage conditions
The shelf life and any special precautions relating to storage conditions will be given.
Installation procedures
- preparation work on the substrate
- composition of roofing on main part of the roof and type of connection of the roofing to its support
- installation process (including joints between sheets) and any points that should be specially mentioned to the contractors.
Repair and maintenance
Detailed repair and maintenance procedures (including the frequency) recommended by the manufacturer/applicant.
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