Jabroof Slimfix in a Structural Pitched Roof - Jablite

156APPLICATION:Roof insulation – structural pitched roofProduct: Jabroof SlimFixTraditional UK roofs are designed and constructed with the insulation at ceilinglevel, leaving a cold roof and under-used loft space. The Jabroof SlimFix insulatedstructural pitched-roof system provides a new method of constructing a tiled orslated pitched roof which offers structural support and, at the same time, satisfiesthe relevant U-value requirements. By spanning from eaves to ridge with aminimum number of purlin supports, the Jabroof SlimFix system also provides auseful insulated space in the roof void.Jabroof SlimFixJabroof SlimFix consists of a sandwichconstruction incorporating a low lambdaexpanded polystyrene (EPS) core andmoisture-resistant chipboard facings toprovide a warm-roof construction. Coldbridging at the structural members iseliminated, substantially reducing the riskof condensation.ConstructionLongitudinal ribs and gutter laths ofEuropean Fir are fitted to the edges of theJabroof SlimFix. Where ridge chamfering ofthe top end of the unit, to match the ridgeboard angle, is carried out in the factory,the top lath will be omitted. The upperlayer of chipboard has a factory-bonded,orange-coloured, moisture resistantchipboard facing, over which are fittedthree vertical counter battens. The lowerchipboard facing has a white finish.Longer spansFor new buildings, a minimum number ofpurlins can be used with the structuralJabroof SlimFix units enabling longer spansto be achieved. (See Jabroof SlimFix spantables 29.3 – 29.8)VentilationCreating a warm-roof construction, whichincludes a breathable sarking membrane,removes the need for ventilation of theroof void.Rooflight openingsSubject to dimensions and position,openings for rooflights or roof windows donot require trimming.Protection to servicesBecause the insulation is at rafter level,the roof space remains warm, providingthermal protection to water services inthe loft.Speed of constructionJabroof SlimFix is available in a choice oflengths providing fast, economicalinstallation. Counter battens and gutterlaths are already fitted. The insulatedstructural pitched roof system has been inuse in Europe for over thirty years.ApprovalsJabroof SlimFix has been assessed andapproved by the British Board of Agrément,certificate number 00/3696. The units aremanufactured in the Netherlands byVencel Resil’s sister company IsoBouwSystems bv.DimensionsLength: 3630 – 7520mmWidth: 1020mmTypeThe insulation core of Jabroof SlimFix issupplied as low lambda EPS and classifiedas Class E, flame-retardant additivematerial, as defined in BS EN 13163.ShapeJabroof SlimFix is square-edged; ridgechamferedunits have a splayed edge atone end only.AccessoriesThe following accessories are available:■ White plastic internal finishing trimsfor the edges if required.■ In-situ polyurethane foam for sealingjoints and gaps.■ Aluminium-butyl rubber tape forsealing horizontal butt joints.■ Hooked nails to suit product.■ Threaded or profiled nails with hooks orwashers to suit product.■ Lifting hoist.FireThe insulation core is manufactured fromClass E, flame-retardant additive material.Where Jabroof SlimFix panels are exposed,12.5mm plasterboard will be required tobe fixed over them once they have beeninstalled, in order to achieve a Class 1Surface Spread of Flame rating. Theexternal fire exposure rating will dependon the selected roof finish.Water-Vapour TransmissionJabroof SlimFix can be consideredto provide a vapour control ifinstalled correctly.

157Roof insulation – structural pitched roofU-valuesApproved documents L1 and L2 will recommend the required U-value for an integrated roof. Table 29.1 gives the U-values achievedbased on the various thicknesses of Jabroof SlimFix.Table 29.1Jabroof SlimFix Product and PropertiesRoof InsulationType: U-value (W/m 2 K)U-valuesOverall*Thickness (mm)Thickness of EPSinsulation (mm) Weight (Kg/m 2 )Jabroof SlimFix 79 8/8 0.37 95 79 14.6Jabroof SlimFix 97 8/8 0.31 113 97 15.3Jabroof SlimFix 113 8/8 0.27 129 113 16Jabroof SlimFix 131 8/8 0.24 147 131 16.7Jabroof SlimFix 157 8/8 0.20 173 157 17.7Jabroof SlimFix 195 8/8 0.16 211 195 19.5*excluding counter battensTable 29.2Jabroof SlimFix 195 plus additional thicknessof Jablite Premium board (mm)U value achieved (W/m²K)25 0.1450 0.1375 0.12100 0.11Table 29.2 shows how the U-value of Jabroof SlimFix 195 can be improved by using an additionalthickness of Jablite Premium board between 50mm-wide timber cross-battens at 600mm centres.For U-values for other combination, please contact Vencel Resil's technical services department.For technical information 0870 444 8769 technical@jablite.co.uk

158APPLICATION:Roof insulation – structural pitched roofFigure 29.1Roof tiles & battensRidge beamJabroof SlimFixcounter battenJabroof SlimFixJablite Premium EPSPurlinBottom facingStructural ornon-structuraltimber studWall plateLongitudinal ribGutter lathStructural floor

159Roof insulation – structural pitched roofINSTALLATIONDesignJabroof SlimFix units are simply lifted The following general points should be(a crane is recommended) and positioned noted:in accordance with the Vencel Resil layout ■ Most roof shapes on plan can bedrawing provided. They are secured, in accommodated.accordance with the Vencel Resil fixing ■ Maximum span depends on the roofschedule provided, to the wallplate, ridge pitch, wind loading, element loading,beam and purlin(s) using a combination of element thickness and weight of thehooked and washered nail fixings supplied roof covering and internal finishes.(See figures 29.2 – 29.5 for typical section ■ The design can incorporate gutterdrawings). All joints between units should overhangs up to 700mm according tobe tightly butted and sealed using the the roof pitch.in-situ polyurethane foam spray supplied, ■ Gable ends can overhang to awhich can also be used to seal gaps at the maximum of 150mm withoutridge. Rooflight apertures are cut outadditional support.when the units have been installed. If ■ Trimming at openings is not requirednecessary, a breathable sarking membrane providing they fall within theis installed. Tile battens are nailed to the longitudinal timber ribs of onecounter battens and the roof finish isstructural unit.installed in the normal way.■ Chimney or flue penetrations shouldinclude a collar or other device toprevent the outer temperature of thechimney or flue exceeding 90°C.■ Accepts a tile or slate finish. Concretetiles do not require a breathablemembrane in this application.For advice on other finishes pleasecontact Vencel Resil’s technical servicesdepartment.■ If the units are to be moved manually,they should be kept upside-down, i.e.with the counter battens downward sothat when they are slid upwards overthe wall plate and purlins damage tothe internal face of the chipboard isavoided.■ Design advice is available from VencelResil’s technical services department.Roof InsulationFor technical information 0870 444 8769 technical@jablite.co.uk

160APPLICATION:Roof insulation – structural pitched roofFigure 29.2Detail at eaves5321461. Jablite Premium EPS2. Jabroof SlimFix – 8mm Chipboard3. Jabroof SlimFix – Counter batten4. Jabroof SlimFix – Fixing5. Roof tile and batten system6. Wall plateNote: Gutter and eaves detail will vary according to requirementsFigure 29.3Detail at ridges1. Jablite Premium EPS2. Jabroof SlimFix – 8mm Chipboard3. Jabroof SlimFix – Counter batten21454. Jabroof SlimFix – Fixing5. Roof tile and batten system6. 12.5mm Plasterboard7. Ridge beam367

161Roof insulation – structural pitched roofFigure 29.4Detail at intermediate purlin5121. Jablite Premium EPS2. Jabroof SlimFix – 8mm Chipboard3. Jabroof SlimFix – Counter batten4. Jabroof SlimFix – Fixing5. Roof tile and batten system6. 12.5mm Plasterboard7. PurlinRoof Insulation3647Figure 29.5Detail at structural stud wall1. Jablite Premium EPS5122. Jabroof SlimFix – 8mm Chipboard3. Jabroof SlimFix – Counter batten4. Jabroof SlimFix – Fixing5. Roof tile and batten system6. 12.5mm Plasterboard7. Structural timber stud3647For technical information 0870 444 8769 technical@jablite.co.uk