Presented By Philip Beveridge

1 Residential Roofing GuidelinesPresented By Philip BeveridgeWeatherproofingPerformance requirements under the NCCThe National Construction Code Building Code of Australia 2019 sets out a number of criteria to be met in relation to Metal requirements: Part -Structure Part -Damp and Weather proofingAcceptable Construction Manuals Part -Roof Cladding, gutters and downpipes and wall claddingSA HB39 Installation code for metal roofing and wall cladding is another regularly referenced document on best practice regarding metal roof installationPerformance requirements under the WeatherproofingA Roof and external wall (Including openings and windows and doors) must prevent the penetration of water that could cause Unhealthy or dangerous conditions Undue dampness or deterioration of building elements Limitations Does not apply to a Class 10 Building (non-habitable buildings or structures)

2 Except where its construction contributes to the weatherproofing of the class 1 building. Metal Roofing LimitationsLimitations cannot be installed in less than 1 pitch quite heavily affected by expansion and durable in benign conditions, 20 year warranty against flake and peel on Colorbond sheeting typically 36 years warranty from corrosion to perforation. Environmental EffectsEnvironmental Effects Selection of Materials: RoofingRecommendedRoofing ProductMarine Environment SeverityDistance from Breaking Surf or Exposed MarineDistance from Calm MarineZINCALUME SteelCOLORBOND SteelCOLORBOND CoolmaxSteelCOLORBOND MetalicSteelBenign 1km 1kmZINCALUME SteelCOLORBOND SteelCOLORBOND Coolmax SteelCOLORBOND Metalic SteelModerate401-1000m201-1000mZINCALUME SteelCOLORBOND SteelCOLORBOND Coolmax SteelMarine201-400m101-200mCOLORBOND Ultra SteelSevere Marine101-200m0-100mCOLORBOND Stainless SteelVery Severe Marine0-100mn/aEnvironmental Effects Selection of Materials.

3 WallingRecommended Walling ProductsDistance from Marine Environment ZINCALUME SteelCOLORBOND steel 1kmCOLORBOND MetallicSteel 1km commercial applications 2km residential applicationsCOLORBOND UltraSteel501-1000mCOLORBOND StainlessSteel0-500mEnvironmental Effects: Dissimilar MetalsEnvironmental Effects: Dissimilar MetalsEnvironmental Effects: Contaminants -AC Condensation lines Incorrect discharge of air-conditioning unit condensation lines is a common cause of corrosion. The discharge of copper saturated water is corrosive to Zincalume steel . Condensation lines should be directed no less than 50mm into a PVC downpipe Rainfall Intensities &Water Carrying CapacityWater Carrying Capacity:The effects of PenetrationsWater Carrying Capacity:The effects of Penetrations Cont.

4 Important to assess the effects penetrations will have on the roof profile. This can be done by calculating the water diversion of blocked pans by traditional tray flashing and soaker methods. Profile assessed to be ok at 30m long, but because of small penetrations diverting water from 3 pans into a singular pan, can cause it to carry as much water as a 44m roof. Water Flow DiagramWater Carrying Capacity -Small Penetrations Small penetrations (150mm or under) should always be liaised with the installing trade , when possible. They should be positioned directly through the rib of a sheet so as to not obstruct water flow inside the Carrying Capacity -Small PenetrationsIf a Penetration blocks an entire pan, a tray flashing should be installed to the high point in the roof to ensure water is diverted away from the Carrying Capacity:Over Capacity Due to Penetrations Large unavoidable penetrations can make the specified roofing profile not suitable.

5 To combat this, we can manually divert water. The new proprietary PopUp Penetration kits are available to do this. Thermal Efficiency & MovementThermal Efficiency:Solar AbsorptanceThermal Efficiency:Determining the appropriate insulationTo determine appropriate insulation, to satisfy BCAS ection J requirements, refer to the ICANZ handbook. This is a free publication available online. Movement: steel ExpansionTable sourced from Lysaght Flashing Guide 2016 Thermal Movement: steel sourced from HB39 Installation code for metal roofing and wall claddingThermal Movement -Flashings When lapping flashingsa)Apply sealant in a continuous steady flowb)Apply sealant throughout the line of intended fasteners for complete bonding Sealed lap should be 25mm.

6 Sealed aluminum rivets or solid fasteners are preferred and are to be spaced at no more than 40 mm centresThermal Movement source: HB39 Installation code of Metal Roofing & Wall Cladding Flashings should cover the roof by at least 150mm. All flashings running parallel with the roof should encompass at least two ribs and therefore create a dry pan .Metal Battens Metal Battens Refer to manufacturers technical manual when determining batten spacing. Most commonly used batten size is 40mm Typically, Metal roof battens can be sufficiently spaced at 900mm centres, however closer at the ridge and eaves to suit end-spans and wind load ratings. Safety battens should be installed if rafters/trusses are spaced over 600mm centres.

7 Battens should always be lapped over a rafter/truss where possible and fixed either side with the correct size screw. Metal Roof Batten Installation Fastener TypesAs per table from the HB39 Installation code for Metal Roof and Wall Cladding, at an absolute minimum, class 3 fasteners should be used. Some commonly used fasteners below:Fastener TypesAs per table from the HB39 Installation code for Metal Roof and Wall Cladding, at an absolute minimum, class 3 fasteners should be used. Some commonly used fasteners below:Fastener TypesAs per table from the HB39 Installation code for Metal Roof and Wall Cladding, at an absolute minimum, class 3 fasteners should be used. Some commonly used fasteners below:Fastener TypesAs per table from the HB39 Installation code for Metal Roof and Wall Cladding, at an absolute minimum, class 3 fasteners should be used.

8 Some commonly used fasteners below:Foot Traffic -Correct walking procedure & Intended traffic design plansRe-roofing & Building ApprovalBuilding ApprovalWhen roofing works involve the replacement of more than 20% of the existing roof area, a Building Approval is Building approval mustbe obtained by eitherthe roofing contractor or the property is responsible??Roofing contractors should ensure quotes and contracts clearly state whether the property owner or the roofing contractor is responsible for obtaining building approvalEaves Gutters, Valleys & Down PipesInstallation of GuttersGutters must be installed with a fall of not less than (i)1:500 for eaves gutters, unless fixed to metal fascia's; and (ii)1:200 for box gutters.

9 Eaves gutters must be (i) supported by brackets securely fixed at stop ends and at not more m centres; and (ii) be capable of removing the overflow volume. This volume will vary with locality and rainfall intensity. Acceptable Overflow MeasuresFront Face Slotted Gutter (a)a minimum slot opening area of 1200 mm2 per metre of gutter; and (b)the lower edge of the slots installed a minimum of 25 mm below the top of the fasciaControlled Back Gap(a)a permanent minimum 10 mm spacer installed between the gutter back and the fascia; and (b)one spacer per bracket, with the spacer not more than 50 mm wide; and (c)the back of the gutter installed a minimum of 10 mm below the top of the Overflow MeasuresControlled Front Bead Height with the front bead of the gutter installed a minimum of 10 mm below the top of the fascia.

10 End Stop WeirWith-(a)A minimum clear width of 100 mm; and (b)The weir edge installed a minimum 25 mm below the top of the fasciaAcceptable Overflow MeasuresInverted Nozzleinstalled within 500 mm of a gutter high point with (a)A minimum nozzle size of 100 mm 50 mm positioned lengthways in the gutter; and (b)The top of the nozzle installed a minimum of 25 mm below the top of the fascia. Front Face WeirWith-(a)A minimum clear width of 200 mm; and (b)A minimum clear height of 20 mm; and (c)The weir edge installed a minimum of 25 mm below the top of the fascia. Acceptable Overflow MeasuresRainwater HeadWith-(a)a 75 mm diameter hole in the outward face of the rainhead; and(b)The centreline of the hole positioned 100 mm below the top of the fascia.