Flat Roof Refurbishment For Metal and Concrete Roof Structures

Transcription

1 Insulati o n First Issue March 2018 See rear cover for applicable countries Flat Roof Refurbishment For Metal and Concrete Roof Structures BEST PRACTICE GUIDE FOR THE MIDDLE EAST Low Energy Low Carbon Buildings

2 Content Page Introduction 03 - Executive Summary 03 - Overview 03 Building Fabric Requirements 04 - U-value Requirements 04 - Thermal Bridging 05 Typical Roof Constructions 06 Fire Performance 07 Ozone Depletion and Global Warming Potential 08 Appendix 1 09 Al Safat 09 - Section 5: Resource Effectiveness: Chapter 1 (501) Conservation and Efficiency: Building Fabric 09 Estidama Pearl Villa Rating System 09 - RE-R1: Minimum Energy Performance Fabric 09 - RE-R2: Cool Building Strategies 09 Abu Dhabi International Energy Conservation Code 09 - Chapter 4: Residential Energy Efficiency 09 - Chapter 5: Commercial Energy Efficiency 09 Appendix 2 10 Al Safat 10 - Section 5: Resource Effectiveness: Chapter 1 (501) Conservation and Efficiency: Building Fabric 10 Abu Dhabi International Energy Conservation Code 10 - Chapter 4: Residential Energy Efficiency 10 - Chapter 5: Commercial Energy Efficiency 10 - UAE Fire and Life Safety Code 10 - Chapter 1: (6) Roofing Systems 10 Appendix 3 11 Dubai Municipality Guidelines 11 - Technical Guideline Number 7 11 Al Safat 11 - Section 7: Resource Effectiveness: Chapter 1 (701) Materials and Waste: Materials and Resources 11 Estidama Pearl Villa Rating System 11 - SM-1: Non-polluting Materials 11 2

3 Introduction Executive Summary Metal and concrete structures are a popular construction in the Middle East and have been for some time. When refurbishing flat roofs, complying with legislation for new buildings is recommended in order to future proof the roof. Approaches to comply with legislation are set out in each of the guidance documents: Estidama; Abu Dhabi Energy Conservation Code; Al Safat; and UAE Fire and Life Safety Code. These are the most up to date and stringent documents in the Middle East, therefore, providing architects, developers and contractors with buildings that are fit for purpose. Kingspan Thermaroof TM products offer a route to meeting various regulations enforced for flat roofs in the region. Heavy rainfall, condensation and humidity levels across the Middle East every year could cause businesses millions of dollars in damage each year due to leaking roofs. Overview Without proper drainage systems and waterproofing installed, heavy rainfall, condensation and humidity levels in the Middle East every year could cause substantial financial losses and damage each year. Metal deck roof structures are especially prone to this. This Technical Bulletin addresses a solution for both metal and concrete roof structures and demonstrates how to comply with local legislation when refurbishing those roofs. Flat roof construction has been utilized throughout the Middle East. 3

4 Building Fabric Requirements U-value Requirements Governments across the Gulf are committing to cut carbon emissions and energy demand, with programmes such as Dubai s integrated energy strategy and Abu Dhabi s Vision As such, throughout the Middle East region, U-values have been improving year over year to enable these energy savings. A U-value is a sum of thermal resistances of the layers that make up a building element (i.e. walls, floors, roofs etc.). This value, measured in W/m 2.K, shows the ability of an element to transmit heat from a warm space to a cold space in a building and, more specifically, from outside to inside the building. If an element has a higher thermal resistance, it has a lower the U-value. The lower the U-value the better insulated the building element is. Across the Middle East, regional building regulations are in place, which prescribe different U-value requirements for architects, consultants and contractors to adhere to when constructing a building. For Dubai, this is the Al Safat regulations; for Abu Dhabi, this is the Abu Dhabi International Energy Code and Estidama; for Riyadh, this is the draft Saudi Arabian Standard, SASO and, where applicable, ASHRAE Energy Standard (for all buildings except low-rise residential buildings) and ASHRAE Energy Standard (for low-rise residential buildings); and for Muscat, ASHRAE Energy Standards 90.1 and 90.2 should be considered as no local standards are in place. These are detailed in the tables below and in Appendix 1. Metal Deck Flat Roof Construction Kingspan Thermaroof TM (0.022) 100mm 0.30 Mineral Wool XPS (0.035) 120mm 110mm Kingspan Thermaroof TM (0.022) 70mm XPS (0.035) 155mm Mineral Wool mm Figure 1: Comparative Insulation Thicknesses to meet a U-value of W/m 2. K on a metal deck flat roof with a suitable waterproofing system. U values (W/m 2. K) Element Abu Dhabi, UAE Dubai, UAE Muscat, Oman Riyadh, Saudi Arabia Roof /0.27 Wall / /3.293 Floor Table 1: U-value regulations for residential buildings across the Gulf Element Abu Dhabi, UAE U values (W/m 2. K) Dubai, UAE Muscat, Oman Riyadh, Saudi Arabia Roof /0.31 Figure 2: Comparative Insulation Thicknesses to meet a U-value of 0.30 W/m 2. K on a metal deck flat roof with a suitable waterproofing system. Concrete Deck Flat Roof Construction Kingspan Thermaroof TM (0.022) 100mm XPS (0.035) 155mm Mineral Wool mm Wall / /0.857 Floor Table 2: U-value regulations for residential buildings across the Gulf Kingspan Thermaroof TM products can be used in the refurbishment of a metal deck flat roof. The following shows guidance on how the U-values for Abu Dhabi and Dubai can be met with Kingspan Thermaroof TM compared to alternative insulation materials. Figure 3: Comparative Insulation Thicknesses to meet a U-value of W/m 2. K on a concrete deck flat roof with a suitable waterproofing system. 4

5 0.30 Kingspan Thermaroof TM (0.022) 70mm XPS (0.035) 110mm Mineral Wool mm Kingspan Thermaroof TR22 installed on a roof in the UAE. Figure 4: Comparative Insulation Thicknesses to meet a U-value of 0.30 W/m 2. K on a concrete deck flat roof with a suitable waterproofing system. Products in the Kingspan Thermaroof TM range can easily achieve the U-value requirements in the GCC. Kingspan Insulation assisted Abu Dhabi Urban Planning Council, at Cityscape Exhibition 2015, teaching residents of the emirate about the benefits of insulation. Calculations, conducted by Abu Dhabi Urban Planning Council, concluded that using 150 mm of Kingspan Thermaroof TM TR27 LPC/FM can reduce heat transfer through the roof by 90%. Thermal Bridging Thermal bridging is now recognised as an important consideration in the construction detailing of a roof. Details of which are available in Appendix 2. A thermal bridge, can be defined as an area that has greater or lesser heat transfer than adjacent areas. When calculating the energy and emissions performance of a building, three types of thermal bridges are considered: l repeating (linear & point); l linear (non repeating); and l point (non repeating). Repeating thermal bridges occur where there are regular interruptions within the building fabric, by materials with poorer insulating properties e.g. fixings and fasteners. The differing (typically additional) heat flow incurred by a repeating thermal bridge should be accounted for in the U value calculation for the building element containing the bridge. Linear (non repeating) thermal bridges occur at intermittent points in the building fabric where either: l the thermal insulation layer is discontinuous, e.g. sills and jambs around the windows in a roof-light within the roof construction; or l where the inside surface area of a construction is different from that of inside surface area, e.g. at the corner where the wall meets the roof. Point (non-repeating) thermal bridges occur where there is an interruption that isn t repeating within the building fabric. It is occasionally used as an adjustment to a U-value for an element, this might be used as an adjustment to a planar U-value to take account of fixings or fasteners, or possibly as an adjustment for isolated steel beams or columns. The differing heat flow (typically, but not always, greater than that through the adjoining plane elements) attributable to the thermal bridge, is the linear thermal transmittance of the bridge, measured in W/m.K, referred to as psi value and expressed as ψ value. The lower the ψ value, the better the performance. Reasonable provision must be made to limit the effects of thermal bridging. The design should ensure that roof light or ventilator kerbs etc. are always insulated with the same thickness of insulation as the general roof area. A mm thick upstand should be used around the perimeter of the roof on the internal façade of parapets. A minimum distance of 300 mm should be maintained between the top of the insulation upstand and the bottom of the horizontal roof insulation. Kingspan Thermaroof TM products are available in 20 & 25 mm thicknesses for use around the perimeters, roof-lights and ventilator kerbs. 5

6 Typical Roof Constructions Metal Deck with No Ceiling Metal Deck with No Ceiling Damp proof course (DPC) Waterproofing e.g. single ply non bituminous membrane Kingspan Thermaroof TM TR22 Damp proof course (DPC) Waterproofing e.g. single ply non bituminous membrane Kingspan Thermaroof TM TR26 LPC/FM Metal deck Metal deck Vapour control layer (not required if metal deck is sealed) Insulation upstand min. 300 mm from bottom surface of horizontal insulation layer Vapour control layer (not required if metal deck is sealed) Insulation upstand min. 300 mm from bottom surface of horizontal insulation layer Figure 5: High Compressive Strength Insulation Cover Board for use in overlaying new or existing metal and concrete deck flat roofs, waterproofed with suitable single-ply and cold liquid applied waterproofing. Figure 6: Insulation for metal flat roofs waterproofed with mechanically fixed single-ply waterproofing. Dense Concrete Deck with Dropped Ceiling Metal Deck with No Ceiling Damp proof course (DPC) Damp proof course (DPC) Paving Slab Screed Bedding Waterproofing e.g. single ply non bituminous membrane Kingspan Thermaroof TM TR27 LPC/FM Waterproofing e.g. single ply non bituminous membrane Kingspan Thermaroof TM TR27 LPC/FM Separation Layer Metal deck 50 mm screed to falls 150 mm concrete deck Vapour control layer Vapour control layer (not required if metal deck is sealed) Insulation upstand min. 300 mm from bottom surface of horizontal insulation layer 12.5 mm ceiling tiles hung from 600 x 600 mm suspension grid Insulation upstand min. 300 mm from bottom surface of horizontal insulation layer Kingspan Kooltherm TM K5 External wall board taken up as high as the external wall Figure 7: Insulation for Metal or Concrete deck flat roofs waterproofed with suitable fully adhered single-ply and cold liquid applied waterproofing. Figure 8: Insulation for concrete deck flat roofs waterproofed with suitable single-ply and cold liquid applied waterproofing. 6

7 Fire Performance The fire performance of insulation materials is a key factor in determining their suitability for specific applications. Arguably the best measure of the fire performance of an insulation product is how the insurance industry perceives its use in buildings. This has been recognised by the UAE Fire & Life Safety Code, whereby roofing constructions are now required to be certified as Class 1 as per Factory Mutual Research Standards 4450: 1989 (Approval Standard for Class 1 Insulated Steel Deck Pass) and 4470: 2010 (Approval Standard for Single-Ply, Polymer-Modified Bitumen Sheet, Built-Up Roof (BUR) and Liquid Applied Roof Assemblies for use in Class 1 Noncombustible Roof Deck Construction), details of which are provided in Appendix 3. Kingspan Thermaroof TM TR26 and TR27 LPC/FM, produced at our Pembridge, U.K. manufacturing facility, is certified as achieving Class 1 Insulated Steel Deck Pass to FM Standard: 4450, subject to the conditions of the approval as a roof insulation product for use in Class 1 roof constructions as described in the current edition of the Factory Mutual Research Approval Guide. Kingspan Thermaroof TR27 LPC/FM 7

8 Ozone Depletion and Global Warming Potential It is important to understand that, whilst reducing the energy consumption and related carbon dioxide emissions of a building, thermal insulation can negatively impact on climate change and ozone depletion, if it is not manufactured in a responsible way. Blowing agents are typically used to enhance the thermal performance of PIR, Phenolic, EPS and XPS insulation, by filling the cells within the insulation with a low thermal conductivity gas. This gas can be released into the atmosphere through various channels, such as during the manufacture of the product, during transit or after the product is ceased to be used. Additionally, open cell insulation materials will allow the blowing agent to disperse into the atmosphere. Blowing agents used in the manufacture of the aforementioned insulation products, such as CFCs, HCFCs and HFCs, can accelerate climate change and ozone depletion if they are released into the atmosphere. A blowing agents impact on ozone depletion and climate change is characterised by its Ozone Depletion Potential (ODP) or Global Warming Potential (GWP). For more information on Ozone Depletion and Global Warming Potential, a technical bulletin is available at: Estidama Pearl Villa Rating System and Dubai Municipalities Technical Guideline Number 7: Policy on the control of Ozone Depleting Substances provide guidance and regulation around this issue. The phase out of these harmful substances is imminent across the UAE, with insulation products using these substances already prohibited in Abu Dhabi. All products in the Kingspan Therma TM range are manufactured with blowing agents that are deemed to have, or have, a zero Ozone Depletion Potential (ODP) and a Global Warming Potential (GWP) < 5. ODP Kingspan Thermaroof TR22 Based on the above, Kingspan Insulation LLC can confirm that Kingspan Thermaroof TM can be used in this situation and such a construction meets the various regulations enforced for flat roofs in the region: Estidama; Abu Dhabi Energy Conservation Code; Al Safat; and UAE Fire and Life Safety Code. For detailed information on the specific construction details related to LPCB or FM Approvals and other installation advice please contact the Kingspan Insulation Technical Services Department. 8

9 Appendix 1 Within Al Sa fat, minimum mandatory U-values must be met, which are listed below for Bronze and Silver Sa fa. Al Sa fat goes beyond mandatory requirements and provides more stringent U-values for those buildings wanting to achieve Gold and Platinum Sa fa. Within Abu Dhabi International Energy Conservation Code, Chapter 5 Commercial Energy Efficiency, commercial buildings must comply with the below U-values. If they do not comply with the below, the building must prove that it exceeds ASHRAE (Energy Standard for Buildings Except for Low-Rise Residential Buildings) by at least 25%. Figure 9 Within Estidama Pearl Villa Rating System, section RE-R1: Minimum Energy Performance, a prescriptive method of compliance is listed. Figure 13 NB Group R refers to places providing accommodations for overnight stay (excluding institutional). Examples: Hotels and Motels. Within Saudi Standard SASO, thermal transmittance values for low-rise / residential buildings should not exceed the values in table 2. Figure 10 Within Estidama Pearl Villa Rating System, section RE-2: Cool Building Strategies, an optional prescriptive method of compliance is also listed. Figure 14 ASHRAE Energy Standard (for all buildings except low-rise residential buildings) and ASHRAE Energy Standard (for low-rise residential buildings) provide building envelope requirements in climate zone 1, a climate similar to that in the Middle East. Figure 11 Within Abu Dhabi International Energy Conservation Code, Chapter 4 Residential Energy Efficiency, with the exception of villas, which are listed above, residential buildings must comply with the below U-values. Figure 12 Figure 15 9

10 Appendix 2 Al Sa fat also provides guidance on thermal bridging by recommending that U-values do not exceed 0.40 W/m2.K at any point in the building envelope. Provisions should also be made to insulate all areas of the building. UAE Fire and Life Safety Code sets out the requirements for roofing assemblies with insulation above or below the deck. This must be followed for all buildings except private villas, commercial villas and agricultural buildings. The following roofing constructions are also exempt from the below: l brick, masonry or concrete exposed roof deck; l tiles / slates made up of concrete or clay; and l copper or ferrous sheets / shingles. Figure 16 Abu Dhabi International Energy Conservation code recommends considering a continuous air barrier throughout the building envelope. Figure 19 Figure 17 Figure 20 Figure 18 10

11 Appendix 3 Within the Dubai Municipalities guidance document which enforces the phase-out of CFCs and HCFCs entitled Technical Guideline Number 7: Policy on the control of Ozone Depleting Substances, insulation manufacturers should have ceased the use of CFCs and their use should have been phased out by the start of This document ensures compliance with the obligations of Montreal Protocol for Article 5 countries. Within the Estidama Rating Systems, 1 credit point is available if all thermal insulation materials used have an Ozone Depletion Potential of zero (ODP=0) and a Global Warming Potential of less than 5 (GWP 5). This includes all blowing agents used in the manufacture of the insulation, but also, all those used to spray it in place, if required. Figure 24 Figure 21 Within Dubai Municipalities guidance document, Al Sa fat, Dubai Green Building Evaluation System, thermal and acoustical insulation materials must be manufactured without the use of CFCs. Figure 22 Additionally, within Al Sa fat, heating, ventilation and air-conditioning (HVAC) equipment must contain refridgerants with zero ODP and a GWP of less than 100. Figure 23 11

12 Kingspan Insulation LLC reserves the right to amend product specifications without prior notice. Product thicknesses shown in this document should not be taken as being available ex stock and advice should be sought directly from Kingspan Insulation LLC. The information, technical details and fixing instructions etc. included in this literature are given in good faith and apply to uses described herein. Recommendations for use should be verified as to the suitability and compliance with actual requirements, specifications and any applicable codes, laws and regulations. For other applications or conditions of use, contact Kingspan Insulation LLC. Advice should be sought for uses of Kingspan Insulation products that are not specifically described herein. The fire tests referenced in this literature and the assigned results are not intended to reflect hazards presented by the materials and products described herein under actual fire conditions. Please check that your copy of the literature is current by visiting Kingspan Insulation LLC P.O. Box , Dubai Investment Park 2, Dubai, U.A.E. Tel: Fax: info@kingspaninsulation.ae Countries comprise: the Middle East as far North and East as (and including) Turkey, Iran and Oman and as far South and West as (and including) Saudi Arabia and Yemen. Kingspan, Kooltherm, and the Lion Device are Trademarks of the Kingspan Group plc