Isover HVAC Application Handbook Installing fire protection insulation to metal ductwork

Isover HVAC Application Handbook Installing fire protection insulation to metal ductwork

HVAC - Fire protection of metal ductwork Fire protection Thermal insulation Isover ULTIMATE TM Protect - Fire protection for metal ductwork It is vital to develop safe, durable and reliable fire protection solutions for ventilation systems as a fire can easily spread from the point of origin via ductwork. Produced with Isover glass wool technology Isover Ultimate Protect is an innovative new generation mineral wool that combines all the advantages of conventional thermal and acoustic insulation with top level fire protection. Providing excellent fire resistance and top-rated reaction to fire, Isover Ultimate Protect fulfils the requirements of BS 476: Part 24 for ventilation and smoke extract ducts. The Isover Ultimate Protect product range, also known as U Protect, consists of Slab and Wired Mat solutions. Offering up to two hours fire protection for both vertical and horizontal applications of rectangular and circular ductwork systems. + + = Effective fire protection A top performer when it comes to material stability and thermal resistance at high temperatures, Isover Ultimate Protect offers a Euroclass A1 fire rating and has been certified to comply with BS 476: Part 24. Ease of installation Excellent manageability ensures that cutting, bending and fitting is faster and more efficient. The Isover Ultimate Protect Wired Mat range is specifically designed for easy installation on circular ductwork. Lightweight 65% lighter than conventional stone wool products, Isover Ultimate Protect makes light work of installation and its low pack weight meets the most stringent of workplace Health and Safety standards. up to 65% lighter than traditional stone wool 2 www.isover.co.uk

Effective fire protection Euroclass harmonisation Commonly accepted in England, Scotland and Wales, Euroclass is a harmonised European classification system (A1, A2, B, C, D, E and F) for products, measuring their reaction to fire. A1 corresponds to the safest situation, E the most dangerous and F would not be classified. Isover Ultimate Protect achieves Euroclass A1 rating, the fire classification for product of non-combustibility. Reaction to fire Under reaction to fire, one of the most important issues is the potential for flashover. This is the spontaneous ignition of hot smoke, gases and fuel which can lead to a fire spreading uncontrollably. Isover Ultimate Protect does not promote flashover. Other hazards found in fires and for risk assessment, are classified by s and d. These relate to the quantity of smoke production (s1 being the lowest production of smoke up to s3, which means high production of smoke) and the possible fall of flaming droplets d (d0 none, up to d3). Isover Ultimate Protect has an index of s1, d0 fire rating classification. Class 0 compliance Class 0 compliance refers to the surface properties of a product, specifically Surface Spread of Flame or non-combustability of the surface. BS 476: Parts 6 and 7 also needs to be satisfied. Isover Ultimate Protect range has a Class 0 foil and passes both these tests. Isover Ultimate Protect exceeds all these standards proving its excellent fire credentials Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 3

HVAC - Fire protection of metal ductwork protection Fire insulation Thermal Why use Isover ULTIMATE TM Protect? Easy and fast installation Ultra-light and adaptable, the Isover Ultimate Protect range makes cutting, bending or filling, faster and more efficient than ever. Lightweight Up to 65% lighter than conventional thermal, acoustic and fire insulation products, Isover Ultimate Protect s low pack weight and grip-friendly touch also meet the most stringent standards for Health and Safety in the workplace. Features Meets BS 476: Part 24 for ventilation ductwork Euroclass A1 fire rating; Class 0 compliance High levels of thermal performance Superior acoustic performance Up to 65% lighter than traditional stone wool systems Easy to cut, bend and fit Off-cuts can be used Only need glue at wall penetrations No need for pre-fabrication High quality mineral wool Benefits Increased fire protection performance Totally non-combustible, top level reaction to fire performance Meets all UK thermal Building Regulations and offers energy savings 50% better sound absorption than typical competitor products Easier to handle 50% faster installation Standard insulators knife can be used Minimises waste on site Less glue required, faster installation Cost savings Will not absorb moisture from the surrounding air and is chemically inert - will not accelerate corrosion of steel, copper or aluminium Performance will not deteriorate over time - long product life, no ageing of product Compression resistance - product will not sag or consolidate over time in normal applications up to 50% quicker installation time than traditional solutions 4 www.isover.co.uk

Installation detail Before you start A. Choose the insulation thicknesses Choose the appropriate thickness from the table below by selecting the desired duct type, fire rating, duct orientation and fire location. Isover Ultimate Protect thickness table Rectangular duct Circular duct Fire location Fire class 1 hour 2 hours Duct orientation Fire inside duct Inside 60mm 80mm* Horizontal 80mm 100mm Vertical Fire outside duct Outside 60mm 80mm* Horizontal 60mm 80mm* Vertical In case both fire locations need to be covered Both 60mm 80mm* Horizontal 80mm 100mm Vertical Use of 1 product for both duct orientations Outside 60mm 80mm* Inside 80mm 100mm Both Use of 1 product for all cases Both 80mm 100mm Both Fire location Fire class 1 hour 2 hours Duct orientation Fire inside duct Inside 75mm 120mm Horizontal 75mm 120mm Vertical Fire outside duct Outside 75mm 120mm Horizontal 75mm 120mm Vertical In case both fire locations need to be covered Both 75mm 120mm Horizontal 75mm 120mm Vertical Use of 1 product for both duct orientations Outside 75mm 100mm Inside 75mm 120mm Both Use of 1 product for all cases Both 75mm 120mm Both For rectangular ducts use U Protect 4.0 Alu 1 Slab and for circular ducts use U Protect 4.0 Alu Wired Mat. *Smoke extraction requires 2 hours fire protection. Note that for rectangular ducts these insulation thicknesses should be increased from 80mm as shown in the table to 90mm. Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 5

HVAC - Fire protection of metal ductwork Fire protection Thermal insulation Kitchen extract Type B kitchen extract solution Rectangular duct Fire location Inside Fire Class 1 hour 2 hours Duct orientation Kitchen Extract 60mm 80mm Horizontal 80mm 100mm Vertical Circular duct Fire location Inside Fire Class 1 hour 2 hours Duct orientation Kitchen Extract 75mm 120mm Horizontal 75mm 120mm Vertical For rectangular ducts use U Protect 4.0 Alu 1 Slab and for circular ducts use U Protect 4.0 Alu Wired Mat. Many specifiers and approval authorities consider that a fire inside a kitchen is the most difficult scenario for a kitchen extract system. This is simulated in test standards, BS476: Part 24: 1987, with a fire inside the duct (Type B) where: a) the inside of kitchen ductwork is required to be cleaned regularly (as per the HVAC s publication TR/19) and therefore the amount of grease should be minimal; and b) the extract system is likely to vent a fire away from the duct, and from the kitchen. This would mean that the kitchen extract fire protection solution would be the same as that prescribed for Type B ventilation duct systems, ensuring that they meet the required integrity, insulation and stability criteria of the previously mentioned standards. Should the approval authority be concerned that a fire in a compartment next to a kitchen could ignite grease that has built up within the duct, and thus cause a fire in the kitchen, then the guidance in BS476: Part24: 1987 for kitchen extract ducts with combustible linings should be used. Please contact our Technical department on 01928 796 180 or email: techinsulation@saint-gobain.com Insulation product range Product Order Thickness Width Length Slabs per m 2 per Packs per m 2 per Code (mm) (mm) (mm) pack pack pallet pallet Ultimate Protect Slab 4.0 Alu 1 Ultimate Protect Wired Mat 4.0 Alu 1 6 www.isover.co.uk 5200414575 60 600 1200 6 4.32 12 51.84 5200414577 80 600 1200 5 3.60 12 43.20 5200414578 100 600 1200 4 2.88 12 34.56 5200432184 75 600 4000 2 4.80 18 86.40 5200432186 120 600 2500 2 3.00 18 54.00

Choose the insulation thickness: Summary Isover Ultimate TM Protect applications: Supply and extract ventilation systems Smoke extract Kitchen extract Isover Ultimate Protect performance summary: Thickness requirements of slabs for rectangular ductwork 1 hour protection 1 hour fire protection horizontal ventilation and smoke extract ductwork: 60mm Isover Ultimate Protect Slab 1 hour fire protection vertical ventilation and smoke extract ductwork: 80mm Isover Ultimate Protect Slab 1 hour fire protection horizontal Type B kitchen extract: 60mm Isover Ultimate Protect Slab 2 hours protection 2 hours fire protection horizontal ventilation ductwork: 80mm Isover Ultimate Protect Slab 2 hours fire protection vertical smoke extract ductwork: 100mm Isover Ultimate Protect Slab 2 hours fire protection vertical ventilation and smoke extract ductwork: 100mm Isover Ultimate Protect Slab 2 hours fire protection vertical Type B kitchen extract: 100mm Isover Ultimate Protect Slab Thickness requirements of Wired Mats for circular ductwork 1 hour fire protection for all applications: 75mm Isover Ultimate Protect Wired Mat 2 hours fire protection for all applications: 120mm Isover Ultimate Protect Wired Mat Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 7

HVAC - Fire protection of metal ductwork Fire protection Thermal insulation B. Choose pins and pin fixing positions Steel pin information The insulation is fixed to the duct using steel pins, 2.7mm to 3mm nominal diameter, and spring steel washers, minimum 38mm diameter. The pins are stud-welded or self-drilling steel pins. Pin options Stud welded or self-drilling pins Self-drilling pins e.g. LENNE IBS1 self-drilling screw pins OR Pins that include a steel base plate which fasten to the duct (minimum of two M4 steel self-drilling/ self-tapping screws or two M4 steel rivets, e.g. Big head M5/B23 studs) NOTE: The length of pin should be equal to the insulation thickness + 3mm Pin fixing positions Horizontal and vertical rectangular ducts See pin pattern pages 9 and 10 Horizontal circular ducts No pins required Vertical circular ducts Vertical installation requires that the insulation mats are to be secured with pins and washers Place 2.7mm diameter pins and 30mm washers around the duct with c 250mm, at 100mm distance from all mat joints. For further information on the Isover Ultimate Protect range, please contact us on 0115 969 8010 email: techinsulation@saint-gobain.com or for technical advice please call 01928 796 180 8 www.isover.co.uk

There are two simple rules that apply: The distance of the self drilling pins OR stud welded pins from the edge of the duct OR the slab joints should not exceed 80mm. The maximum distance between pin OR Isover FireProtect Screws should not exceed 260mm. These apply to all rectangular duct orientations. See page 10 for cross-section of duct and slab overlaps. Rectangular horizontal ducts Underside slabs (note the side slabs are omitted) Example of pin positions and Isover FireProtect Screw positions l = 1200mm 1200mm l = 1200mm l 420mm 420mm Side slabs (note the top slab is omitted) l 420mm Example shows overlapping of the side slabs onto the underside slabs l = 1200mm l = 1200mm l 420 l = 1200mm l 420mm l 420mm l 420mm Key = Pins = Isover FireProtect Screw l 420 l 420mm NOTE: No glue or pins are used to fix the top slab. These are only fixed with the use of Isover FireProtect Screws, (shown above as the top row). l 420 Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 9

HVAC - Fire protection of metal ductwork Fire protection Thermal insulation Rectangular vertical ducts Example of pin positions and Isover FireProtect Screw positions Overlapping on main duct face Side slabs showing pin positions 1200mm l = l = l = l 420 l 420 l 420mm & Wool & Wool 420mm thickness 90mm l or 420 or & Wool l 400mm thickness & Wool & Wool 90 thickness = 100mm or or l 400 & Wool 400 Wool For rectangular thickness vertical = 100 ducts, apply the largest board to the longest side leaving an overlap equivalent thickness to the thickness 100 of the U Protect slab, on either side of the duct. Repeat for the other side, then place the smaller boards between the overlaps created from the first two steps. 10 www.isover.co.uk

C. Calculate the amount of glue and paint needed Typical coverage rates for a penetration: Isover Protect BSF Intumescent Paint and Isover Protect BSK Adhesive both supplied in 15kg tubs. Volume 7.9 litres OR supplied in 310ml tubes. Weight 0.59kg. Coverage rates are given below per linear metre of joint in Isover Ultimate Protect Slab and Wired Mat, based on a thickness of 2mm. On-site usage of paint / glue will vary - these coverage rates should therefore be used for guidance purposes only. How much paint and glue is required: 1) Calculate the total linear metreage of the penetration using the following sum: (4 x width of duct) + (4 x height of duct - (2 x insulation thickness in metres)). 2) Select the insulation thickness requirement from the table below, read across the table to identify the approximate weight (kg) of Isover Protect BSF Intumescent Paint and Isover Protect BSK Adhesive required per linear metre. 3) To calculate the total paint / glue required for this job, use the following: Total linear metreage of the penetration (calculated in step 1) x approximate weight (kg) of Isover Protect BSF Intumescent paint / Isover Protect BSK Adhesive (identified in step 2). 4) Use this final figure to determine if the job requires a 15kg Tub or a 310ml (0.59kg) tube, by comparing the total weight calculated in Step 3 to the corresponding tub / tube weight. Thickness of Isover Protect BSF Intumescent Paint Isover Protect BSK Adhesive Ultimate Slab Approximate weight Approximate volume Approximate weight Approximate volume (kg) of Isover Protect (l) of Isover Protect (kg) of Isover Protect (l) of Isover Protect BSF Intumescent BSF Intumescent BSK Adhesive per BSK Adhesive per Paint per linear Paint per linear linear metre linear metre metre at penetration metre at penetration at penetration at penetration 30 0.12 0.06 0.12 0.06 40 0.15 0.08 0.15 0.08 50 0.19 0.10 0.19 0.10 60 0.20 0.10 0.24 0.12 70 0.20 0.10 0.26 0.14 80 0.20 0.10 0.32 0.16 90 0.20 0.10 0.36 0.18 100 0.20 0.10 0.39 0.20 For further information on the Isover Ultimate Protect range, please contact us on 0115 969 8010 email: techinsulation@saint-gobain.com or for technical advice please call 01928 796 180 Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 11

HVAC - Fire protection of metal ductwork Fire protection Thermal insulation D. Complete wall / floor penetrations 5 steps to installation Installation through the construction is completed in 5 steps. The same general principle is used for both rectangular and circular ducts regardless of duct orientation. Step 1: Positioning Place the duct in the penetration of the construction, with a 50mm gap between the duct wall and opening. Fit a stiffener (steel tube) to the duct where the duct passes through the penetration. NOTE: Stiffeners are not used with circular ducts Step 2: Insulation Using the same insulation being used for the rest of the duct, fully pack the space between the duct and the partition. Ensure tight compression in order to completely fill the opening. Step 3: Sealing Using a spatula apply an approx 2mm thick layer of Isover Protect BSF to BOTH sides of the construction, to seal the joint. < Isover Protect BSF Intumescent Paint 310ml tube < Isover Protect BSF Intumescent Paint 15kg tub 12 www.isover.co.uk

Installation procedure Step 4a: Reinforcing a rectangular duct Fix an L-profile (30mm x 30mm x 3mm) around the duct on both sides of the construction with steel rivets. Using two steel screws for each side, ensure the top and bottom profiles are fixed to the construction. Step 4b: Reinforcing a circular duct Steps 1-3 are completed using U Protect Wired Mat. Screw a suspension bracket (30mm x 2mm) to the duct on both sides of the construction. Fix long L-profiles (30mm x 30mm x 3mm) above and below the bracket with one rivet each (4mm x 13mm). Fix short L-profiles (30mm x 30mm x 3mm) with nuts and bolts (M8) to the bracket eye. The use of L-profiles is part of the integrity requirements of BS 476: Part 24 and is a compulsory requirement with all manufacturers passive fire protection systems. Step 5: Duct insulation Glue the ends of the insulation to the construction using Isover Protect BSK Adhesive (thickness approx 2mm). Install the insulation so that it is adjacent and tightly fitted against the penetration. The insulation must be cut leaving excess length, so that it exerts some pressure between the penetration and the last fitted piece of insulation. This applies to both rectangular and circular ducts. Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 13

HVAC - Fire protection of metal ductwork Fire protection Thermal insulation E. Complete the installation Horizontal and vertical rectangular ducts Secure the corner joints with Isover FireProtect Screws (Three screws per side at 300mm centres). The screw length must be twice the insulation thickness. Isover FireProtect Screws No glue or pins Top slab covering side slabs Welded pins Isover Ultimate Protect slab, Isover FireProtect Screw and pin position for horizontal ducts Installation principle for horizontal circular ducts 14 www.isover.co.uk Isover Ultimate Protect slab, Isover FireProtect Screw and pin position for vertical ducts Isover Ultimate Protect insulation slabs need to be cut to fit the duct as tightly as possible. The insulation may need to be cut to fit around flanged duct joints (see left). Horizontal and vertical circular ducts Using clamping rings, secure the joints of the insulation mats together; or bind the edges of the wired mats together with stainless steel wired, minimum 1.5mm in diameter. For ducts greater than 1000mm diameter (up to 1250mm diameter), add a 120mm wide x 30mm thick collar of insulation over the duct joints to protect the flanges. Use standard threaded rods and suspension brackets as hangers for the duct. Place these hangers inside the insulation. The rods do not need to be protected by insulation, except the first 30mm of the drop rod (see pages 18-19). For vertical circular ducts, fix the insulation using self-drilling or self-tapping pins, spaced at 250mm nominal centres (see page 8). Note: There is no need to cut the insulation at the duct joint due to the flexibility of the insulation.

Installation procedure Access hatch design Any access hatch needs to be easy to remove and replace, therefore the design must maintain the strength of the duct section and not interrupt a cross joint or stiffener. The hatch can be a proprietary design provided that it is securely fastened to the duct. The Isover Ultimate Protect insulation slabs can overlap the opening (see below), or can have a stepped perimeter. The pigtail screw type of fixing can be used, provided that it is capable of being used repeatedly. Alternatively the fixings can penetrate through the fixed insulation to the steel duct. Access panels Isover FireProtect Screws Slab with the same thickness as the one needed for the classification Two or three-sided ducts Isover Protect BSK Adhesive is to be used between the insulation slab edges and the soffit. If the gap between the duct and soffit is less than 50mm, no additional fixtures are needed. < Isover Protect BSK Adhesive For larger distances (up to 100mm), a metal angle 50mm x 50mm x 1.2mm should be fitted internally and fixed to the slab with a proprietary metal fixing at max 300mm centres. Additional Stud Welded Pins or Self-Drilling Pins should be fixed to the metal angle at the required centres. < Isover Protect BSK Adhesive < Isover Protect BSK Adhesive < < Isover FireProtect Screws, fixed at required centres Stud Welded Pins or Self-Drilling Pins, fixed at required centres < < Stud Welded Pins or Self-Drilling Pins, fixed at required centres Isover FireProtect Screws, fixed at required centres Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 15

HVAC - Fire protection of metal ductwork Fire protection Thermal insulation Preparation of rectangular ductwork prior to insulating Duct sheeting The steel duct is constructed in sections of hot dipped galvanised steel sheet, mild steel sheet or stainless steel sheet, minimum 0.7mm thick. Thickness of steel sheet 0.7mm 0.8mm 1.0mm Maximum size of duct (longer side) Up to 1250mm Up to 1500mm Up to 2000mm Maximum duct sizes: Rectangular ducts 2000mm x 1500mm Drop rods and hangers for rectangular horizontal ducts Each steel hanger consists of two threaded drop rods, minimum M10, and a channel section bearer, minimum 30mm x 30mm x 3mm thick. Fasten the bearer to the drop rods using hexagonal nuts and washers. Each hanger must be positioned so that it is adjacent to (within 250mm of) a cross joint or stiffening collar. The maximum spacing of the hangers is 1250mm. The spacing of the hangers and the size of the steel hanger components must be adjusted so that the tensile stress in the rods and the bending stress in the channels do not exceed 15N/mm 2 for fire resistance periods up to 60 minutes and 10N/mm 2 for fire resistance periods up to 120 minutes. The drop rods and bearers are positioned inside the insulation material, with the drop rods nominally 10mm from the steel duct. NOTE: The steel frame to be independently fire rated. Drop rod anchors When fixing to a concrete construction Use all-steel expanding anchors to fasten the threaded rod hangers to concrete soffits. The drop rod anchors should penetrate the concrete by at least 50mm, to achieve 120 minutes of fire resistance. When fixing to a steel supporting construction Drill a hole through the steel member, allowing the drop rod anchors to be supported by a steel nut and washer above. If a clamp type fixing is used, the clamp must be steel, suitable for the purpose. It should pass around the steel member and be fastened back on itself. 16 www.isover.co.uk

Preparation of ductwork Flanges As per HVAC Specification DW144, typically use J3 and above at maximum 1250mm centres. Using spot welds at 150mm nominal centres fasten the Lindab flanges or equivalent, (minimum size 30mm x 30mm x 1.2mm thick) at each cross joint. Fasten the flanges together with 40mm steel clamps at 265mm maximum centres. Use a ceramic tape gasket (20mm wide x 3mm thick) between the flanges to seal the joints. See Figure below: The Lindab flanges are fitted with steel corner plates (minimum 95mm x 95mm x 2.5mm thick). Slot these into the flanges at each corner and bolt them together with an M10 steel nut and bolt at each corner. Stiffeners Attach steel stiffeners at 90 angles to any side of the duct section where the width or depth exceeds 500mm. Position these at mid-width / depth and mid-length in each duct section. Each stiffener should consist of a steel tube (16mm diameter x 2mm thick) Fasten the stiffeners to the duct walls with a steel washer of the same size, on the outside of the duct wall. Use 72mm diameter x 1mm thick washers to fasten the stiffener, on the inside with M6 steel bolts. Rectangular duct showing stiffener NOTE: Clamps that rely on friction to hold them in place are not suitable. Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 17

HVAC - Fire protection of metal ductwork Fire protection Thermal insulation Supports for rectangular vertical ducts The steel section can either span across the opening in the concrete floor or form part of a cantilever bracket that is fastened to the building structure. To prevent buckling of the duct, the distance between supports should not exceed eight times the smallest lateral dimension across the outside face of the steel duct. The weight of the duct system is taken by the building structure at each floor level. Stiffening collars - refer to DW144 If the longer side of the duct is greater than 1500mm, and the ducts have a section length greater than 625mm, then a stiffening collar is required. 1. Fit each collar to the duct at approximately mid-length. The collar should be made to the same size steel section as the cross joints (or equivalent). Suspension system spacing rectangular vertical ducts The maximum vertical distance between supports is 5000mm. 1. Fasten steel sections to the steel duct in order to support the duct system vertically. The maximum vertical distance between supports is 5000mm. 2. The supporting steel members, where they emerge from the protection around the duct, must be clad with the same thickness of insulation for at least 300mm. 2. Weld or bolt the sections together at the corners and fasten to the duct walls with steel rivets (or equivalent) at maximum 300mm centres, or spot-welds at maximum 150mm centres. Rectangular horizontal ducts The maximum distance between supports should not exceed 1250mm. For more information on the Isover Ultimate Protect range, please visit www.isover.co.uk 18 www.isover.co.uk

Preparation of ductwork Preparation of circular ductwork prior to insulating Duct sheeting The spirally wound steel duct is constructed in sections up to 3000mm long using hot dipped galvanised steel sheet, mild steel sheet or stainless steel sheet, 0.7mm thick. Thickness of steel sheet 0.7mm 1.0mm Maximum diameter of duct Up to 1000mm Up to 1250mm Maximum duct sizes: 1250mm diameter Drop rods and hangers for circular horizontal ducts Each steel hanger consists of two threaded drop The ends of each band section are bent rods, minimum M8, and a two-part circular band, outwards. Fasten the band sections together 25mm wide x 2mm thick. The maximum spacing and attach to the drop rods with hexagonal of the hangers is 1200mm. nuts and washers. Position the drop rods and bearers inside the insulation material, with the drop rods 10mm from the steel duct. NB: The spacing of the hangers and the size of the steel hanger components must be adjusted so that the tensile stress in the rods and the bands do not exceed 15N/mm 2 for fire resistance periods up to 60 minutes and 10N/mm 2 for fire resistance periods up to 120 minutes. Drop rod anchors When fixing to a concrete supporting construction Use all-steel expanding anchors to fasten the threaded rod hangers to concrete soffits. The drop rod anchors should penetrate the concrete by at least 50mm, to achieve 120 minutes of fire resistance. When fixing to a steel supporting construction Drill a hole through the steel member, allowing the drop rod anchors to be supported by a steel nut and washer above. If a clamp type fixing is used, the clamp must be steel, suitable for the purpose. It should pass around the steel member and be fastened back on itself. NOTE: Clamps that rely on friction to hold them in place are not suitable. Technical enquiries: techinsulation@saint-gobain.com or 01928 796180 19

HVAC - Fire protection of metal ductwork protection Fire insulation Thermal Joints As per HVAC Specification DW144. The spirally wound steel duct is constructed in sections up to 3000mm long using hot dipped galvanised steel sheet, mild steel sheet or stainless steel sheet, 0.7mm thick. The spiral seam of the spirally wound ducts must be the grooved seam, Lindab SR Series or equivalent. Stiffeners Where 120 minutes of fire resistance is required for steel ducts, 40mm x 5mm steel flanges should be positioned approx 10mm from each duct connection. Supports for circular vertical ducts The steel sections either span across the opening in the concrete floor or form part of a cantilever bracket that is fastened to the building structure. The maximum vertical distance between supports is 5000mm. The distance between supports should not exceed eight times the smallest lateral dimension across the outside face of the steel duct, to prevent buckling of the duct. The weight of the duct system is taken by the building structure at each floor level. Suspension system spacing Circular horizontal ducts The maximum distance between supports should not exceed 1200mm. 1. Fasten minimum M4 steel self-tapping screws to the duct at 150mm centres on both sides of the joint, at each cross joint Lindab NPU steel sleeves (or equivalent), minimum size 100mm wide and thickness as per following: 0.6mm up to 500mm diameter 0.7mm from 501mm up to 709mm 0.9mm from 710mm up to 1000mm Flanged connections from 1001-1250mm 2. Fit a sealing strip of EPDM rubber and a ceramic tape gasket, 15mm wide x 3mm thick, between the sleeve and the duct, on both sides of the joint, to seal the joints. 1. Fasten steel sections to the steel duct, either along the two longer sides, or on all four sides. 2. Clad the supporting steel members, where they emerge from the protection around the duct, with the same thickness of insulation for at least 300mm. Circular vertical ducts The maximum vertical distance between supports is 5000mm. For further information on the Isover ULTIMATE Protect range, please contact us on 0115 969 8010 email: techinsulation@saint-gobain.com or for technical advice please call 01928 796 180 20 www.isover.co.uk

Technical Insulation Preparation of ductwork including HVAC, Marine and OEM Dedicated Technical Helpline Tel: 01928 796 180 email: techinsulation@saint-gobain.com Advice on >> Compliance with Building Regulations for Pipework and Ductwork solutions >> Consultant performance specifications >> Technical Product range and system applications >> Heat Loss and energy savings calculations www.isover.co.uk

Less Materials Less Energy Less Emissions www.3pointplan.co.uk www.isover.co.uk Isover Order Placement or Order Enquiries: Tel: 0800 032 2555 Fax: 0800 917 9188 Publish date: March 2012 Isover Document Reference: FPI-IG-12-03 Technical Insulation - Technical Enquiries Tel: 01928 796 180 Email: techinsulation@saint-gobain.com Saint-Gobain Isover UK Commercial Centre Gotham Business Park Leake Road Gotham Nottinghamshire NG11 0LB Tel: 0115 969 8010 Fax: 0115 983 1675 Email: isover@saint-gobain.com Isover reserves the right to revise product specifications without notice. The information in this document was correct to the best of our knowledge at the time of publication. It is the users responsibility to ensure that it remains current prior to use. The information in this document is for guidance only and should not be read in isolation. Users should read and familiarise themselves with all the information contained in this document and ensure that they are fully conversant with the products and systems being used, before subsequent specification or installation. For a comprehensive and up to date library of information visit the Isover website.