APPLICATION: Roof insulation warm pitched roof

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2 138 APPLICATION: Product: Jabroof Premium panel Jabroof Premium panel is specially designed to be incorporated into warm pitched-roof constructions to provide a high level of insulation to meet the current Building Regulations requirements. The panels are placed immediately below the roof covering where they also insulate the rafters, thus avoiding cold-bridging; a layer of plasterboard is fixed below the insulation to provide the necessary fire performance. Jabroof Premium panels Jabroof Premium panels provide insulation above and between the rafters to give a warm-roof construction. Cold bridging at the structural members is eliminated, substantially reducing the risk of condensation. Easy to handle Jabroof Premium panels are manufactured from low lambda expanded polystyrene (EPS) which is lightweight and easy to handle. Permanent Jabroof Premium panels are rot-proof and durable and will remain effective for the life of the building. Environment Expanded polystyrene has been awarded an A+ rating by the BRE s Green Guide to Specification. Ventilation Creating a warm-roof construction which incorporates a breathable sarking membrane removes the need for ventilation of the roof void. Rafter variations Jabroof Premium panels are available in a range of sizes and edge-profile dimensions to suit different rafter centres and thicknesses; panels are also available with an offset edge profile to suit double-lapped rafters. Protection to services Because Jabroof Premium panels are positioned at rafter level, the roof space remains warm, providing thermal protection to water services in the loft area. Type Jabroof Premium panels are supplied as EPS 100 as defined in BS EN Reaction to Fire Class E, containing a flame retardant additive. Dimensions Standard size: length 1200mm width to suit 600, 450 and 400mm rafter centres. Thickness: 65, 95, 145 and 190mm; other thicknesses are available to order. Edge profile rebated to suit nominal 38 or 50mm single- or double-lapped rafters. Shape The edge profile provides support for the panel on the rafter and includes a recess for the counter battens used to retain the panel in position. Figure 25.1 shows the profile dimensions. Water-vapour transmission Jabroof Premium panel has a significant resistance to the passage of water vapour, but should not be regarded as a vapourcontrol layer. However, in this application, a vapour-control layer need only be considered where the system is used over areas of high humidity or high water-vapour emissions. Fire A protective layer of plasterboard must be provided to the underside of the rafters in order to provide the necessary standard of fire protection. U-values Table 25.1 shows the U-values achieved based on various thicknesses of Jabroof Premium panel. The values given are based on a k-value of 0.030W/mK for the insulation. Their calculation complies with the procedures contained in the Conventions for U-value calculations document.

3 139 Table 25.1 U-values (W/m 2 K) Thickness (mm) 400mm centres 600mm centres 65mm mm Roof Insulation 145mm mm Other thicknesses are available to order. Figure Dimension (mm) X Y X Y For technical information technical@jablite.co.uk

4 140 APPLICATION: Figure 25.2 Roof tile and batten system Breathable sarking membrane Treated timber counter batten Treated timber stop end Jabroof Premium panel Rafter

5 141 INSTALLATION Figures show typical methods of installing Jabroof Premium panels with single- and double-lapped rafters. Rafters The rafters should be positioned at the required centres, preferably using a Jabroof Premium panel of the required size as a template to ensure accurate spacing. Any internal cross-bracing of the rafters should be installed in the normal way. Figure 25.3 Finished installation Roof Insulation Fitting Jabroof Premium panels The first run of Jabroof Premium panels is installed from the ridge towards the eaves; the first panel should be splay-cut at the ridge board to match the pitch of the rafters. The rafter run is completed by installing full panels towards the eaves. The last panel should be cut to length and splay-cut to the required angle to match the rafter ends. Each successive rafter-run across the roof should be installed in the same way. Once all the panel runs have been installed, a 38x50mm-wide treated timber batten should be attached to the tops of the rafters at the eaves, abutting the last run of Jabroof Premium panels. This provides a stop end to retain the panels in position. The panels are secured using a 38x50mmwide treated timber counter batten positioned in the recess formed between two rows of panels. The batten should be nailed in using 3.35mm diameter nails, 115mm long, in accordance with BS 5534:Part 1; alternatively, details of suitable proprietary fixings are available from Vencel Resil s technical services department. The counter batten should overlap, and be nailed to, the stop end Jabroof Premium panel 2. Breathable sarking membrane 3. Roof tile and batten system mm Plasterboard 5. Treated timber counter batten Figure 25.4 Jabroof Premium panel section Jabroof Premium panel 2. Roof tile and batten system 3. Breathable sarking membrane mm Plasterboard 5. Treated timber counter batten 6. Ventilated void 5 For technical information technical@jablite.co.uk

6 142 Lapped rafters If lapped rafters occur in the run, a specially-designed Jabroof Premium panel is available to accommodate the wider rafter opening required on one side. These panels are 1200mm long and are intended to be cut to length on site; at either side of the lapped rafter, these panels will match the profile of the standard Jabroof Premium panels. Figure 25.5 Jabroof Premium panel section with lapped rafters Jabroof Premium panel 2. Roof tile and batten system 3. Breathable sarking membrane mm Plasterboard 5. Treated timber counter batten 6. Ventilated void 7. Double rafter Maintaining the insulation envelope In order to complete the insulation envelope and to prevent the occurrence of cold bridges and areas of discontinuity in the insulation, the Jabroof Premium panels should meet the wall and gable insulation; any gaps should be filled with a suitable in-situ expanding foam sealant. Ridges, abutments and other penetrations should also be sealed Breathable sarking membrane A proprietary breathable roof-tile underlay should be installed over the counter battens and detailed at the eaves, gables, valleys etc in accordance with the manufacturer s recommendations. Details of suitable products are available from Vencel Resil s technical services department. Tile battens and tiles The tile battens should be fixed to the counter battens using 3.35mm diameter nails, 65mm long, and the tiles installed in the normal manner. The work should be carried out in accordance with BS 5534:Part 1, and following the tile manufacturer s instructions. Internal finish The underside of the rafters should be lined with 12.5mm thick plasterboard and finished as required. This provides mechanical protection to the insulation and provides the required degree of fire performance. Vapour-control layer A vapour-control layer is not an essential part of the normal specification. However, if conditions of use are such that consistently high levels of moisture vapour will be present in the roof space, it is suggested that a vapour-control layer be positioned immediately behind the protective layer of plasterboard. References BS 5534 Code of practice for slating and tiling. Part 1 Design. BS EN Thermal insulation products for buildings Factory made products of expanded polystyrene (EPS) Specification.

7 198 Jablite Premium Low lambda Expanded Polystyrene (EPS) Technical Information Jablite Premium low lambda EPS is a lightweight cellular plastic material suitable for a wide range of applications. Uniquely identifiable by its grey board with orange speckles, it is an excellent insulating medium which exhibits consistent thermal performance over the range of temperatures normally encountered in buildings. Technical Description Composition Jablite Premium is manufactured from EPS. The material comprises of expanded beads of low lambda polystyrene pre-foamed and fused together in a steam-heated mould under pressure. This produces a block of material, up to 7314mm long, which is then cut to size and/or shape. After cutting to size, the material may be faced or laminated with other materials to suit its application. Alternatively, the beads, may be moulded into a finished shaped section which requires no further processing. Jablite Premium is supplied as Reaction to Fire Class E, containing a flame-retardant additive. Typical properties of Jablite Premium Mechanical Properties Compressive 10% compression (kpa) Tolerances In accordance with BS EN tolerances on the cut dimensions are defined as follows: Length: ± 3mm or ± 0.6% whichever is greater (L1) Width: ± 3mm or ± 0.6% whichever is greater (W1) Thickness: ± 2mm (T1) Squareness: ± 5mm per 1000mm (S1). Alternative tolerances can be provided for specific applications. Dimensional stability: ± 0.5% under constant laboratory conditions (DS(N)5) Jablite Premium Type EPS 70 EPS Standards Jablite Premium is produced to the requirements of BS EN Thermal insulation products for buildings Factory made products of expanded polystyrene (EPS) specification. Vencel Resil Limited has been assessed and approved to BS EN ISO 9001 (2000) Quality Management Systems Requirements. Properties and Performance Mechanical properties Jablite Premium has a high strength to weight ratio. Moisture Properties Although Jablite Premium has significant resistance to the passage of water vapour, it should not be regarded as a damp-proof membrane or vapour-control layer, and will not provide a barrier against damp penetration. A suitable damp-proof membrane or vapour-control layer will be required in most forms of construction see individual product and application data. Compressive 1% nominal strain (kpa) Bending strength (kpa) Moisture Properties Water vapour diffusion resistance factor µ Water vapour permeability δ mg/(pa.h.m) Vapour resistivity (MNs/gm) Thermal Properties Thermal conductivity (W/mK, at 10ºC) Thermal resistivity (mk/w)

8 199 Fire Properties In common with all organic materials, Jablite Premium is combustible. However, provided it is specified and installed correctly, in accordance with the manufacturer s instructions and BS 6203 guidance, it will not present any undue fire hazard. The standard recommends that for all applications, the material should be protected by either a laminated facing layer, or fully enclosed by the form of construction. Class E flame-retardant additive material reduces the rate of flame spread but should not be considered as offering enhanced fire performance. Combustion EPS is combustible as defined in BS 476: Part 4. When burning, EPS behaves like other hydrocarbons such as wood and paper. Class E material products of uncontrolled combustion are carbon monoxide, carbon dioxide, styrene, hydrogen bromide and water vapour; the decomposing styrene will give off a certain amount of dense black soot. Ignition temperature Flash ignition temperature is between 350ºC and 490ºC depending on the application and the exact circumstances of use. Under certain circumstances the material can be readily ignited by a naked flame but providing it is correctly installed, this does not present any disadvantage in use. Biological Properties EPS will not sustain mould growth, and has no nutrient value to insects or vermin. The material is non-biodegradable and care should be taken to dispose of waste and off cuts at a licensed waste site. Thermal Properties Thermal movement Coefficient of linear expansion: 0.6 x 10-6ºC. The material is sufficiently resilient and flexible that no allowance need be made for thermal expansion. Working temperature range EPS can be used within the temperature range -150ºC to +80ºC. Compatibility with other materials EPS is soluble in aromatic, halogenated solvents and ketones; it should be protected from contact with hydrocarbons and strong solvents using a suitable membrane. EPS should not be permitted to come into contact with PVC-sheathed electrical cables since this will lead to migration of plasticiser from the PVC resulting in embrittlement of the cable sheath. Cables should be protected by the use of a physical barrier, for example by being enclosed in a conduit or by an air gap. Health, Safety and Environment EPS is non-toxic and biologically inert. It is not irritating to the eyes or skin and no medical treatment or action is required as a result of accidental ingestion. No special precautions are required during handling or cutting when carried out in well-ventilated areas. The volume of EPS boards is 98% air; consequently the components in a given volume are typically 18-26kg/m 3. In polystyrene, styrene monomer, shown to be safe in use, constitutes a maximum of 0.1% by weight of the product. This minute trace of styrene monomer constitutes no threat to health. The expanding agent, pentane is a saturated hydrocarbon and is non-toxic and constitutes no threat to the ozone layer. EPS, Class E, flame-retardant additive material, contains around 0.5% of the flame-retardant hexa-bromocyclododecane(hbcd) which is entrapped in the polymer matrix of the EPS. Storage Store Jablite Premium boards under cover, protected from high winds and out of direct sunlight. Care should be taken in storage not to bring the boards into contact with highly flammable materials such as paint, solvent or petroleum products. Smoking should be prohibited in the storage area and the products must not be exposed to flame or other ignition source. Technical data Jablite Premium For technical information technical@jablite.co.uk

9 For more information about Jablite please contact us on: Tel: Visit: Jablite Limited Head Office: Infinity House, Anderson Way, Belvedere, Kent DA17 6BG