CI/SfB (2-) Rn7 (M2) Full Fill Cavity Wall Specification Guide

Transcription

1 CI/SfB (2-) Rn7 (M2) Full Fill Cavity Wall Specification Guide 1

2 Contents Introduction 3 Product Properties Certification Sustainability Specification Support Building Regulations U-value Tables 11 Design Considerations and Installation Guidelines 12 General Information 15 2

3 Introduction Cavity wall construction still remains the predominant build method within the UK. Consisting typically of a masonry inner and outer skin, separated by a cavity forming one part of a whole house approach. Today s challenge for building professionals centres around current and future UK Building Regulations and achieving an optimised compromise between performance, cost and compliance. Celotex CF5000 is a premium performance full fill cavity wall solution and is BBA certified. Making use of the whole cavity width, CF5000 optimises the thermal performance through the wall and such, achieves lower U-values without having to widen the cavity. Celotex CF5000 features a super low lambda value of 0.021W/mK helping you achieve compliance to UK Building Regulations and a U-value within the wall of 0.18 W/m 2 K. CF5000 has been mechanically engineered with a rebated edge to eliminate the passage of moisture. Designed with installation efficiency in mind, CF5000 is easy to cut and comes in 1200x450mm dimensions to fit with standard cavity wall tie spacing. Cavity wall construction still remains the predominant build method within the UK 3

4 Product Properties Celotex CF5000 Celotex CF5000 is a full fill cavity wall board with a rigid polyisocyanurate foam core adhesively bonded in the manufacturing process to aluminium foil facings on both sides. CF5000 has been specifically engineered with a rebated edge to maximise thermal performance and eliminate the passage of moisture. Dimensions: 1200mm x 450mm. Thickness: 97mm. Compressive Strength: 120 kpa BS EN 826:2013 (Thermal insulating products for building applications determination of compressive behaviour). Dimensional: DS (70, 90)3, DS (-20,-)4 BS EN 1604:2013 (Thermal insulating products for building applications determination of dimensional stability under specified temperature and humidity conditions). Thermal Performance: Celotex CF5000 has a declared thermal conductivity (λ-value) of W/mK in accordance with BS EN 13165:2012+A1:2015 (Thermal insulation for products factory made rigid polyurethane foam (PUR) products). Cavity Wall Insulation Celotex CF5000 Technical Data Product Code Thickness (mm) R-value (m 2 K/W) Weight (kg/m 2 ) CF Full Fill Cavity Wall Specification Guide

5 Fire Performance Cavity Wall Insulation Celotex CF5000 is Class O fire rated as described by the National Building Regulations, having achieved: A pass to BS 476 Part 6:1989 (Fire tests on building materials and structures method of test for fire propagation for products). Classification as Class 1 in accordance BS 476 Part 7:1997 (Fire tests on building materials and structures method of test to determine the classification of the surface spread of flame of products). 5

6 Certification Third party approvals play a key role in distinguishing product performance between different manufacturers. To eradicate the perception that all PIR is the same, we recognise the importance of approvals and certifications from a number of leading organisations, including BBA, BRE and ISO. These approvals include independent validation of thermal, fire and other product standards. As part of our BBA certification, Celotex CF5000 has undergone rigorous testing for moisture transfer from the outside elements, including wind driven rain to the inside of the wall. Product Code Application BBA No. ISO 9001 ISO CF5000 Full Fill Cavity Wall 94/3080 Product Sheet 2 6 Full Fill Cavity Wall Specification Guide

7 Sustainability Suitable for use within a number of applications within the building fabric, the specification of Celotex products will significantly contribute to improving the energy efficiency of the UK s building stock. Celotex is also able to independently certify the environmental impact for a selection of its product ranges. This includes Celotex CF5000. Measured by its BRE Ecopoint score, Celotex achieve the lowest environmental impact of any PIR manufacturer and from its most recent recertification, has improved this score by over 5% since Moreover, when compared to the generic PIR Ecopoint value, Celotex impact is over 20% better than that of noncertified PIR manufacturers. Celotex manufacture solutions that start saving energy as soon as they are installed. Over its useful life, PIR insulation saves over 100 times more energy than was used in its manufacture Full Fill Cavity Wall Insulation Through its BRE Approved Environmental Profile, Celotex was the first PIR manufacturer to achieve an A+ Green Guide rating. This rating has been maintained through ongoing recertification and now includes even more Celotex products as part of the profile. Celotex products are all manufactured in accordance with environmental management system ISO As well as this, the suppliers of the principal raw materials used in the manufacture of Celotex products also possess this standard allowing a credit to be achieved within the Materials category of BREEAM assessments. Name of Insulation Material Manufacturer Unfoamed, Foamed or Installed using Propellants Global Warming Potential (GWP) Blowing Agent CF5000 Celotex Foamed Less than 5 Pentane For further information please see Celotex Sustainability Guide available at celotex.co.uk Green Guide Rating A+ Element Number Environmental Management System (EMS) - Key Process ISO Environmental Management System (EMS) - Supply Chain Process ISO

8 Specification Support Energy Assessments For more information on how to download Celotex CF5000 for BIM, visit celotex.co.uk/bim Customers should be aware that Celotex and Darren Evans Assessments are separate legal entities and Celotex makes no warranty as to the quality of the services that DEA provides and assumes no responsibility in connection with those services. Customers should also be aware that, as an Assured Partner of Celotex, Darren Evans Assessments operate under a commercial agreement with Celotex for services provided by Darren Evans Assessments under the Celotex Energy Assessment Service. Specification Clause Celotex CF5000 The full fill cavity wall insulation shall be Celotex CF mm thick, comprising a polyisocyanurate (PIR) rigid foam insulation core providing textured aluminium foil facings on both sides and Class O fire performance throughout the product in accordance with BS 476. CF5000 is A+ rated when compared to the BRE Green Guide 2008 and is CFC/ HCFC free with low GWP and zero ODP and CE marking compliance to BSEN CF5000 has been mechanically engineered with a rebated edge, tightly interlocking during installation to resist the passage of moisture across the cavity. CF5000 is manufactured in accordance with quality management systems ISO 9001 and environmental management system ISO All products must be installed in accordance with instructions issued by Celotex. Building Information Modelling (BIM) Celotex CF5000 is available for BIM in the following software formats: Autodesk Revit Industry Foundation Classes (IFC) Celotex products are available for BIM through both celotex.co.uk/bim and the NBS National BIM Library. NBS Specifications Celotex CF5000 is referenced in the following NBS clause: F30 Accessories/sundry items for brick/ block/stone walling: 10 Full Fill Cavity Insulation (Minor Works) 150 (Standard/Intermediate) Technical Services Celotex provide outstanding levels of technical expertise and personal assistance through two industry leading services: Celotex Technical Centre When it comes to finding easy-tounderstand, quick and helpful advice regarding PIR insulation, the Celotex Technical Centre (CTC) is where you will discover high levels of support and guidance on finding the most appropriate solutions to meet your requirements. This includes provision of: U-value calculations Condensation risk analysis Application and installation advice Guidance on compliance to Building Regulations Information on our product and environmental credentials Call the Celotex Technical Centre on to speak to one of our advisors, or alternatively technical@celotex.co.uk Thermal Bridging Celotex offers a wide range of junction details and these can be downloaded via the Celotex members area. When designed in to a building they offer a significant contribution to the improvement of the fabric energy efficiency. Due to the way whole-building energy calculations work, having better junction details can benefit the designer. As insulation levels increase, the risk of condensation occurring around junctions also increases. Using construction details such as Celotex thermal bridging models helps to address the issue. By improving the performance of the junction, the amount of insulation required in the walls is optimised. Celotex thermal bridging models have low psi values and high temperature factors and can prevent condensation from forming ensuring that mould growth does not occur. Find out more at celotex.co.uk Celotex Energy Assessments Offering energy calculations including SAP, SBEM and bespoke thermal modelling as well as additional services for pre-tender planning and sustainability assessments for BREEAM. For more information on Celotex Energy Assessments (CEA) please take a look at the CEA brochure on celotex.co.uk with a full breakdown of the services we can provide for your project requirements. For more information please phone or info@celotexea.co.uk 8 Full Fill Cavity Wall Specification Guide

9 Building Regulations England Part L 2013 Part L is an Approved Document within the Building Regulations for England dealing with the Conservation of Fuel and Power. It ensures that the design and construction of new buildings, as well as work done on existing buildings, meets targets designed to limit the associated CO 2 emissions from the building following its construction or modification. Below is a guidance table of U-values to help comply with Part L 2013 Building Regulations. New Build Existing Buildings Domestic Notional Value/Backstop Non-Domestic Notional value/ Backstop New Thermal Element e.g. Extensions Existing Thermal Element e.g. Garage Conversions Walls 0.18 / / Floors 0.13 / / Pitched Roofs 0.13 / / Flat Roofs 0.13 / / Scotland Section Section 6 of the Scottish Building Regulations is the Technical Handbook that deals with Energy within the built environment. Section 6 supports the Climate Change (Scotland) Act 2009 as it seeks to meet the target of an 80% reduction in carbon emissions by 2050 by ensuring that effective measures for the conservation of fuel and power are taken with constructing new or modifying existing buildings. Below is a guidance table of U-values to help comply with Section Building Regulations. New Build Existing Buildings Domestic Notional Value/Backstop Non-Domestic Notional Value/ Backstop New Thermal Element e.g. Extensions Existing Thermal Element e.g. Garage Conversions Walls 0.19 / / * / 0.22* 0.30 Floors 0.15 / / * / 0.18* 0.25 Pitched Roofs 0.13 / / * / 0.18* 0.25 Flat Roofs 0.13 / / * / 0.18* 0.25 *Value required when extensions for houses have a reasonable standard of insulation 9

10 Wales Part L 2014 Historically, Part L, the Approved Document for the Conservation of Fuel and Power, applied to Wales and England. In 2014 this changed and the Welsh Government has issued their own version of Part L for use in Wales which came into force on 31st July. Part L ensures that the design and construction of new buildings, as well as work done on existing buildings, meets targets designed to limit the associated CO 2 emissions from the building following its construction or modification. New Build Existing Buildings Domestic Notional Value/ Backstop Non- Domestic Notional value/ Backstop New Thermal Element Retained Thermal Element New Thermal Elements Domestic in Character New Thermal Elements Other Domestic buildings Retained Thermal Elements Walls 0.18 / / Floors 0.13 / / Roofs 0.13 / / Ceiling Full Fill Cavity Wall Specification Guide

11 U-value Tables U-value calculations: full fill cavity wall with Celotex CF5000 Buildup: Brickwork outer leaf / Celotex CF5000 / Blockwork inner leaf / Plasterboard on dabs + 3mm skim Buildup: Render/Blockwork outer leaf / Celotex CF5000 / Blockwork (variable) inner leaf / Plasterboard on dabs + 3mm skim Blocktype (Lambda) Blocktype (Lambda) Product Code Dense (1.13) Medium Dense (0.59) Lightweight Concrete (0.25) Aircrete (0.15) Product Code Dense (1.13) Medium Dense (0.59) Lightweight Concrete (0.25) Aircrete (0.15) CF CF

12 Design Considerations and Installation Guidelines Design Considerations for Celotex CF5000 Thermal Performance U-values The U-value tables on page 11 demonstrate how Celotex CF5000 can contribute to meeting the energy conservation requirements outlined in the Building Regulations (see pages 9 & 10) Linear Thermal Bridging Building Regulations require building designers to consider heat loss through junctions within the construction. This requirement varies in England, Scotland and Wales, however, more emphasis than ever before is being placed, not just on the CO 2 emissions of buildings, but also the energy efficiency. This means a step change to U-values and junction details. Heat loss through junctions can account for 15% of the total loss, and so by utilising better junction details a new range of possibilities opens up to the designer. Lintels As insulation levels increase the risk of condensation occurring around junctions such as lintels also increases. Using construction details, such as those provided by Celotex, helps to address this issue. Firstly, by improving the performance of the junction the amount of insulation required in the walls is optimised. Secondly, as Celotex junction details have low psi values and high temperature factors they can prevent condensation from forming and this ensures that mould growth does not occur. Insulation should ideally abut the head of a window frame to avoid a cold bridge. Wall to Floor Junctions Where insulation is installed under a screed or concrete slab, perimeter upstand insulation should be provided at all exposed edges as shown in Figure 1. The distance maintained between the top of the perimeter upstand insulation and the bottom of the cavity wall insulation should be a minimum of 150mm. Gable Walls At gable walls it is recommended that Celotex CF5000 is taken up to the underside of the roof verges. In cold roof constructions, the product should extend at least 250mm above the ceiling insulation. The top edge of the insulation should be protected with a cavity tray. Resistance to Moisture Building Regulations for the UK govern the use of cavity wall insulation and its correct use is subject to certain criteria. The suitability of the wall for full fill cavity insulation can be determined by assessment using national exposure zone maps for reference, see Approved Document C for England and Wales or Section 3 of the Scottish Regulations. The location of the building is given an index number and a table details the maximum recommended exposure zone for different construction types. Similarly, the type of mortar joint used can also influence specification in construction. Other methods can be used to make a similar assessment. Celotex CF5000 can be installed in accordance with BBA certificate 94/3080 but it should be noted that in severe exposure zones it may not be suitable. In all cases it is advised that reference should be made to the BBA certificate, the relevant Building Regulations and British Standards documents, consultation with Building Control, and, if applicable the building s warranty provider to ensure the correct specification and suitability of a full fill cavity wall product. Wall Ties Only wall ties in accordance with BS EN : 2013 and PD 6697 : 2010 are suitable for use with Celotex CF5000. Cavity Obstructions Unavoidable projections into the cavity, such as floor edge beams and steel columns will interrupt the continuity of Celotex CF5000. Extra care is required to both weatherproof the detail and address thermal bridging. Where Celotex CF5000 stops below and above the projection, the rebated edge should be trimmed using a sharp blade. It is important the rebated edge is cut accurately so that a tight butt edge is formed with the obstruction. The use of a cavity tray with weep holes is recommended. Where the continuity of Celotex CF5000 is interrupted, a flexible fibre insulation material suitable for full fill can be used around the projection to ensure the thermal envelope is continuous. Where buildings are subject to a building warranty such as NHBC standards, the requirements of the warranty provider must be met. Lintels are typically a high risk area for condensation and mould growth if not insulated correctly. By adopting Celotex Junction detail, this risk is minimised and thermal performance of the junction is improved. 12 Full Fill Cavity Wall Specification Guide

13 Fire Cavity Fire Barriers The requirements of the Building Regulations relating to the fire spread in cavity walls can be met in buildings of all purpose groups without the need for fire barriers provided the construction complies with the provision detailed in: England and Wales, Approved Doc B, volume 1, Diagram 13 and Vol2, Diagram 34. Northen Ireland Technical booklet E Diagram 3.5. Scotland: Technical Handbook 2 (Domestic and Non-Domestic) Mandatory standard 2.4, clause 2.4.1, 2.4.2, and For further information please refer to BBA 94/3080. Condensation with BS 5250: 2011, Annexes D and G, and the relevant guidance. A cavity wall with masonry inner and outer leaf with full fill cavity insulation will adequately limit surface condensation provided it does not exceed 0.7W/m 2 K at any point. Areas of thermal bridging, around lintels for example, can lead to condensation and mould growth. By incorporating the construction details published by Celotex in to the design this can be avoided. NHBC Should the building be built under an NHBC guarantee then the wall should be designed and built in line with NHBC technical standards, in particular Chapter 6.1. Full details of the standards should be followed to ensure compliance. Walls will limit the risk of interstitial condensation adequately when they are designed and constructed in accordance Celotex full fill cavity cavity wall insulation wall insulation perimeter upstand insulation screed 150mm minimum polyethene separating layer layer Celotex PIR insulation dpm slab NOTE: Celotex CF5000 rise rise must be be placed against the placed internal against leafthe internal leaf Source: Celotex Cavity Wall BBA Certificate Figure 1. 13

14 Installation Guidelines Celotex CF Build up the first section of the leading leaf to a course above the next row of wall ties. It is desirable that the outer leaf is constructed first to help minimise the number of brick cuts around openings and to clean mortar snots to reduce thermal bridging and contaminated wall ties. The use of a cavity board is important to prevent mortar build up at the bottom of the cavity. 2. The first row of wall ties are positioned at a maximum of 600mm centres horizontally and provide a minimum support of two ties per 1200mm board. 3. The first row of insulation is fitted against the leading leaf on to the first row of wall ties, so the rise of the thinner rebated edge faces away from the external leaf pointing upwards (see figure 2). These should be installed to a minimum depth of 150mm below the damp proof course (DPC) to provide edge insulation to the floor and reduce thermal bridging at this junction. 4. The next board is then fitted tightly to the previous board by slotting the rebated edges together in a jigsaw effect. This is repeated for the first row of boards. * Best Practice Tip Ensure that all exposed areas of insulation are protected with a weatherproof material or board when work is suspended or during rain. 6. The inner leaf is built up to the same level as the insulation. Continue to construct the cavity wall and install insulation following previous steps ensuring excess mortar is removed from the cavity face and a cavity board is used to prevent mortar dropping on the top edge of the insulation. * Best Practice Tip Do not push insulation down in to the cavity as the rebated jigsaw effect between boards cannot be ensured. Openings 7. Where the boards are required to be fitted around openings the rebated edge should be trimmed using a sharp blade. It is important that the rebated edge is cut accurately so that a tight butt edge is formed at the opening external leaf interfaces. Suitable damp proofing should be used around openings. Care should be taken when fitting the extra wall ties around openings in to the rebated edge. * Best Practice Tip Cut the insulation using a sharp knife and straight edge to ensure an accurate butt edge. Corners 8. At corner junctions the boards should be butt jointed by removing the rebated edge. It is important that the rebated edge is cut accurately ensuring all edges are butted tightly with no air gaps achieving continuity of the thermal envelope around the corners. Corner details should include a vertical DPC that is incorporated during construction. following a small cut in to the rebated edge, the wall tie is placed with a slight downward slope towards the external leaf, directing any moisture away from the building internal leaf 5. Wall ties are then laid on to the top surface of the boards. A small cut should be made in to the top surface of the board to recess the wall tie so that it is sloping downwards to the outer leaf. The cut made should be no more than the depth of the rebated edge. Where a wall tie has a drip it can be positioned centrally. Care is taken to avoid damage to the board. * Best Practice Tip Do not pierce the centre of the insulation board with the wall tie. This is a potential point of moisture ingress. Source: Celotex Cavity Wall BBA Certificate Figure 2. For more information please contact the Celotex Technical Centre on or technical@celotex.co.uk 14 Full Fill Cavity Wall Specification Guide

15 General Information Storage Celotex insulation boards should be stored dry, flat and clear of the ground. Only as much material as can be installed during a single working period should be removed from storage at any one time. If boards are stored under tarpaulins, care should be taken to prevent rope damage to boards. Installation Always install Celotex insulation boards in accordance with the instructions supplied by Celotex. Celotex insulation boards should not be installed when the temperature is at or below 4 C and falling. Where possible, cut the product using the Celotex Insulation Saw to minimise dust creation. When cutting Celotex insulation, dust extraction equipment, eye protection and face masks should be provided. Dust or particles in the eyes should be washed out with liberal quantities of water. If skin is sensitive to fibre irritation, apply a barrier cream to exposed areas before handling. Handling Care should also be taken to ensure that packs are not dropped on to corners or edges. Aluminium foil edges may be sharp. Avoid sliding bare hands along board edges. 15

16 Find out more at celotex.co.uk Follow us Team up with us on Like us on Celotex, Lady Lane Industrial Estate, Hadleigh, Ipswich, Suffolk, IP7 6BA T: E: Date of publication: August Full Fill Cavity Wall Specification Guide