Guidelines for the Use of Glass - fhbrundle.co.uk

1 Guidelines for the Use of Glass in Protective BarriersContentsIntroduction1. Scope2. Definitions and descriptions3. Design considerations4. Design criteria5. Barrier types6. Glass types7. InstallationBibliographyAnnex A Conformity with Building RegulationsIntroductionGlazing in protective barriers can be regarded as a safety risk if anindividual can accidentally come into contact with are two specific risks that need consideration and these are: Cutting and piercing injuries resulting from accidental impact; Falling through the glazing if the impact causes breakageNOTE: Injuries resulting from walking into unseen glazing isexcluded from this Data Sheet. This risk can be alleviated by theuse of appropriate manifestation.

2 Advice on manifestation can befound in BS 6262-4:2005, GGF Publication The Right Glazing in theRight Place and the applicable Building ScopeThis Data Sheet covers the use of Glass in protective barriers (generallyreferred to as balustrades) that are designed to offer protection topeople where a difference in height constitutes a falling risk. It covers:a. Full height protective with Glass infill standing Glass protective barriersAs well as giving the basis of design there is an Annex that coversthe situation with respect to conformity with Building Regulations inthe United does not cover curved Glass when used in the above applications. 2. Definitions and DescriptionsNOTE: Definitions , , and Figure 1 are reproducedfrom the appropriate Building Regulations eg Approved Document BarrierAny element of building or structure intended to prevent personsfrom falling and to retain, stop or guide DatumFinished level on which people may stand, floor, roof, balcony,pitch line of stairs external ground, etc.

3 (see Figure 1) Design levelLevel at which the horizontal force on the barrier is assumed to actfor the purpose of design (see Figure 1)November and Glazing FederationTel: 020 7939 9100 Fax: 0870 042 4266 While every attempt is made to present up to dateinformation, this data sheet, produced by the Glassand Glazing Federation, is issued for guidance butwithout responsibility for any advice given therein oromission therefrom or for the consequences of actingin reliance thereon and all liability on the part of theGlass and Glazing Federation however arising in connection therewith is expressly 1 Datum, barrier heightand design height Line loadLoad, horizontal force, which is applied at the design Uniformly distributed loadLoad, wind loading.

4 Applied over the entire surface area of the Concentrated loadLoad applied over a small Impact loadThe load applied when a person falls against the ContainmentAbility of glazing when subjected to impact loading to resistpenetration and hence prevent people from falling through 1: Thermally toughened safety Glass will provide containmentwhen under the applicable impact test it does not 2: Laminated safety Glass will provide containment whenunder the applicable impact test it either does not break or breaks 3: Applicable impact test method, EN BalusterPost supporting the handrail in a HandrailRail acting as a guard or support to be held by hand in : It enables the line load to be transmitted to the structurewithout stressing the Glass .

5 With the exception of free standingprotective barriers ie the handrail shall be connected to the Full height protective barrierThese can take many forms and are not necessarily composed offull floor to ceiling Glass /glazing. If any part of a glazed structure,whether it forms the whole or part of a wall element, extendsbelow the minimum barrier height given in it is classed as a fullheight barrier. See Figure Barrier with Glass infill panelThis type of protective barrier comprises the main frame, and balusters, which carry the appropriate loads. The glassis used to form the infill panel and provides no support to the mainframe. Handrail loads are not transferred to the Glass are four main types of infill panels (see figure 3): Fully framed; Two edge framed Clip fixed Bolt fixedThe two edge frames, clips and bolts can relate to infill panes ineither landscape or portrait 3 Examples of infill panelsNOTE: The application of a structural sealant between adjacentpanes of Glass does not change the support Free-standing Glass protective barrierThis type of protective barrier consists of Glass panes affixed, or bonded, to the structure along the bottom edge (see figure 4).

6 A handrail is generally attached to the top edge ofthe Glass and there are no 4 Examples of free-standing protective barriers3. Design AssessmentWhen assessing the need for a barrier and the type of barrier to Guidelines for the Use of Glass in Protective BarriersFigure 2 Examples of full height protective barriersNOTE: Compliance can be achieved by: installing an appropriatehandrail; or ensuring that the Glass specification will withstand theappropriate provided, consideration should be given to the likely hazards,building use and the risks to building , in a building, more than one use of the building isanticipated, either the barrier design should be chosen to suit theworst case, or more than one type of barrier should be provided,as appropriate, to the Difference in levelsThe protective barrier shall provide guarding when the following apply: In dwellings where the difference in adjacent level is > 600mm; In building other than dwellings where the difference is:On stairs greater than two risers.

7 Other location > Other considerationsThe barrier selected shall be designed so as to minimise the risk ofpersons falling, rolling, sliding or slipping through gaps in the barrierand/or the barriers are used when children under five are present thegap in the barrier shall not exceed 100mm. This dimension is givenwith the applicable Building Regulation. NOTE 1: The 100mm is to prevent the child being held fast by theguarding (see applicable Building Regulation in Bibliography [B1])NOTE 2: Any guarding protecting glazing has to prevent a sphereof 75mm diameter touching the glazing (see applicable buildingregulation in Bibliography [B1])NOTE 3: The break safe criteria for laminated safety Glass and wiredsafety Glass are that no opening through which a 76mm diametersphere can pass.

8 (see EN 12600) : Care should be taken to consider the possible deflectionunder Design IntroductionThe presence of protective barriers may be one of guidance forpersons moving about a building. However, the majority ofprotective barriers are positioned to prevent persons from fallingfrom the edges of floors, stairs, elevated walkways and main requirement of a protective barrier is, therefore, toprovide containment. It performs this function by being able toresist the likely applied forces without excessive deflection andwithout being forces to be resisted are generally described as follows: Line loadis related to the possibility of persons leaning against the barrier, applying a force normal to a conventional barrier at the top edge.

9 It is generally given in the form of kN/m run, applied at a height above finished floor level, datum, roughly equivalent to the waist height of an adult Uniformly distributed load(UDL) is related to the pressure exerted on the infill area (that part of the barrier below the position of application of the line load). It is generally given in the form of kN/m2, applied over the entire infill area. Concentrated loadtakes into account any non-uniformity of the load applied to the infill and may also represent a static equivalent to a localised human impact (from hand, knee, elbow, etc.). It is generally given in the form of kN, applied at the most vulnerable position on the infill 1: Line and concentrated loads are given in Eurocode EN 1991-1-1 and are the subject of a National 2: Uniformly distributed loads are given in Eurocode EN 1991-1-4 and are the subject of a National 3: Minimum horizontal imposed loads for parapets, barriersand balustrades are provided in Table 2 of BS 6180: : Barriers shall be designed to resist the most unfavourablelikely imposed loads, line and concentrated.

10 And wind loadswithout unacceptable deflections or Load valuesThe value of the design loads shall relate to the building with higher usage levels will generally be designed tohigher load design loads and building usage categories can be found inapplicable national Building Regulations. Impact loadingIn addition to the loading requirements given in , which areapplicable to any design of barrier, where Glass is used, theperformance under impact must be performance of glazing is determined under material Europe the appropriate standard is EN 12600. The classificationof flat Glass under this test method is presented as follows: ( )Ф Where: is the highest drop height class at which the product either did not break or broke in accordance with a) or b) of EN 12600: 2002, Clause 4; is the mode of breakage (see Annex A of EN 12600);Фis the highest drop height class at which the product either didnot break or broke in accordance with a) of EN 12600: 2002, Clause Impact classesThe energy level of an impact will vary according to the position ofthe barrier relative to the unhindered distance a body can travel ina direction perpendicular to the surface of the protective barrier(free path - see figure 5).