A flat roof should preferably be insulated from above. Let’s look at the two main types of flat roof: Cold Flat Roof. Others would treat even steeper pitches as flat roofs. The typical U-value of an existing, uninsulated flat roof is 1.5W/m2K. Sketch 1 3 BASIC DESIGN WARM AND COLD ROOFS Householder’s Guide to Flat Roofing In a flat roof, the waterproofing is always supported by a structural roof deck. A ventilation gap, usually 50mm, should be provided between the top of the insulation and underside of the roof covering to allow the air to flow across. SuperHome tours and Q&A sessions will let you quiz the owners, so you can discover what worked and get frank feedback on anything that didn’t. Owners and specifiers alike demand a life - time of high performance. 1 0 obj Roof Insulation for Flat Roofs. through leaks, damp building materials or diffusion through adjoining structural surfaces. A cold roof assembly can also be created using other types of insulation. ROCKWOOL products are available with a bitumen or mineral-coated fiberglass face to be used in a number of roofing solutions. Flat Roof Insulation Roof Insulation is split into two main sections; Cold Roof Insulation and Warm Roof Insulation . Types Of Flat Roof. Ventilation is required for these roofs. Best insulation material Rigid PIR insulation boards, such as Mannok Therm Roof / MR boards, are generally the preferred roof insulation materials for flat roofs for a number of reasons.They are lightweight, easy to fit and come in a range of thicknesses. The membrane is then attached to the insulation. Fiberboard is not an insulation. Draught-proofing- a good thing? cold deck: this is where the insulation is placed between the joists/rafters or in between the ceiling joists in the case of a pitch roof. <> In both warm deck and cold deck options, the weather membrane (typically formed of roofing felt and bitumen) will be the topmost layer, protecting against rain. Where insulation depth is restricted by the flat roof construction, it may be necessary to install the roof insulation between and below the joists to create a cold deck structure. A layer of rigid insulation board can be added either on top of the roof’s weatherproof layer or directly on top of the timber roof surface, with a new weatherproof layer on top of the insulation. In the case of a warm flat roof, the vapour barrier lies above the ceiling and roof construction. alternatively I presume I could use 125mm of kingspan (polyurethane) (without foil) and use polypropylene sheet as a vapour barrier. structure. At Roofgiant, we stock warm and cold roof options for both flat and pitched roofs, providing you with everything from PIR to foil insulation to rafter roll and many other forms of insulation designed for your loft or attic space. Contact the manufacturer of the selected insulation to discuss the technical requirements and assess the potential for interstitial condensation. Firstly, it is always more economical to insulate a flat roof when you are replacing the roof covering anyway. The only point of putting the insulation on top of the waterproof membrane is when you can’t take it off, as when, for example, it is bitumen. Figure 12: Unvented Flat Roof Assembly: Condensing Surface Temperature Controlled—The thickness of the rigid insulation at both the roof deck and perimeter is determined by a calculation procedure similar to Figure 5; the colder the climate, the thicker the rigid insulation required; the higher the interior moisture level, the thicker the rigid insulation required These figures are approximate and vary according to the construction type and material used. More importantly, they have excellent thermal properties and compressive strength, which makes them ideal for flat roof insulation. x����o�6�� ��� ��oE��i���&���A��["u��`�����ȵ�� �LK���_E��oW˫l�"/_��W�l�u>#��I���h�߷��C�X��jY䣋�/+��� �(����JN�$������'��`��o�\ �lF�XG6�P�� �vva����IGe�m�� ����T%���3��^c���8 �*��y�h?�����0�R���H$¿���R����+�@�*�Q��l��H&�o. The best way to deal with this is to add insulation. The existing ceiling is sound but provides no insulation. However, over the last few decades new and advanced materials have been developed. Cold roof insulation is typically made from mineral wool and has multiple uses. 2 0 obj It protects thermal insulation where there is a possibility of moisture entry, e.g. For guidance on roof insulation please contact us on (+44) 01257 488 000. It might not be the best solution for flat roof insulation, but it does still have its uses in certain projects. On top of this goes the roof covering. The waterproof layer is above the insulation and a vapour control layer is placed below the insulation. According to the Energy Saving Trust, a quarter of heat is lost through the roof in an uninsulated home. endobj This may help with condensation, but causes such a loss of heat that it has been banned in Scotland. Flat roof insulation is yet another way to properly protect your home from unwanted external and internal effects and provide your home preferable thermal and acoustic comfort. With an inverted warm roof construction, put ballast, usually graded pebbles or concrete paving slabs, on top of the insulation in order to keep the insulation down in the event of wind. Where insulation depth is restricted by the flat roof construction, it may be necessary to install the roof insulation between and below the joists to create a cold deck structure. In BS 6229, a roof is defined as flat if it has an overall pitch of 10 degrees or less. stream Building regulations. This method of insulation can also be used to upgrade the thermal performance of an existing roof … A product like pro clima INTELLOplus features humidity-variable diffusion resistance that is effective in most if not all climates. The target should be to achieve a U-value of 0.25W/m2K or better. It should be of the maximum available thickness. There are two basic categories of roof design: A warm roof has the insulation above the structural deck, which is thus kept warm. <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 595.32 842.04] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> The roof covering is then laid over the ply. Flat Roof. Warm Roof In the case of a flat roof, insulation is usually in the form of either a rigid board above the deck, or a fibrous quilt immediately above the ceiling, depending on the type of roof construction. This makes them a great source of ideas to help you green your own home. Insulation can also help to limit condensation and contribute to acoustic insulation (depending on the type of insulation used). a) I have a cold roof which is already vented (I believe anFAnderson roofing system) b) I need to maintain a 50mm gap below flat roof c) I need 125mm of kingspan beneath this (with foil) to act as vapour barrier. These Insulation products have great R-value and fire rating for these applications. Depending on the roof type your property possesses, you need to consider how to insulate, where to insulate, and the thickness required. SuperHomes is coordinated by the With solutions ranging from our OPTIM-R vacuum insulation panels to our Therma range of PIR insulation, we can provide the best solution for flat roof insulation for roofs with mechanically fixed, bonded or torch applied waterproofing systems. Roof insulation thickness for building regulations will vary depending on the type of insulation used. Cold Roof. It should be of the maximum available thickness. Sedum roof covering Unfortunately, too many dwellings suffer from this problem. Flat Roof. Our range of high and optimum performance flat roof insulation products are suitable for use in a range of flat roofs. They lose loads of heat, and are prone to leaking, causing the materials to deteriorate. (its about 30 years old). Be the first to hear about Open Days, Funding and Key Reports and download our FREE Eco retrofit beginner’s guide, Sustainable Home Refurbishment: The Earthscan Expert Guide to Retrofitting Homes for Efficiency, Wood fibre batts (adhered / mechanically fixed), Mineral wool slab (adhered / mechanically fixed), Practical refurbishment of solid-walled houses (CE184), Energy efficient loft conversions (CE120), Energy efficient refurbishment of existing housing (CE83). If you're unsure as to the difference between warm roof insulation and cold roof insulation, keep reading. Kingspan and Recticel are the two of the most well-known flat roof insulation brands and they’re firm favourites of Insulation Superstore customers. There are two basic categories of roof design: A warm roof has the insulation above the structural deck, which is thus kept warm. A typical installation would find 80-100mm of PUR insulation laid over a deck made of plywood (conforming to BS5268 Part 2 and to BS EN 636 Part 3, and of quality grades C-D and C-C) or Orientated Strand Board (manufactured to BS EN300 and be certified by BBA or WIMLAS), with a further 38mm of PIR insulation fitted between the roof joists, immediately below the deck. When you insulate a flat roof it is important that moisture or air are kept well out, all around. Careful detailing at the edge and parapet areas of a flat roof is vital for reliability and durability. 3 0 obj Of all the Roof Insulation products on the market, we have listed two of the best Roof Insulation products below. At Roofgiant, we stock warm and cold roof options for both flat and pitched roofs, providing you with everything from PIR to foil insulation to rafter roll and many other forms of insulation designed for your loft or attic space. This means there is a vapour control layer in the ceiling and cross ventilation at the eaves or the top of the walls. You could even buy insulation and floor boards that are already bonded together, which … Also See: Cold Deck – The thickness of insulation required will vary depending on the material you decide to use and the manufacturer’s specification. Cold Roof… Flat roof design guide. • Cold Deck Flat Roof The thickness of insulation required will vary depending on the material you decide to use and the manufacturer’s specification. Ventilation is required for these roofs. Cold deck or cold roof is where the insulation is below the roof deck (and the associated joists). It has only 1-r value per inch and is always installed in 0.5 inch thickness. And how? Inverted warm deck flat roof insulation – click to enlarge. Visit a house with flat roof insulation in Sep 2016 But where? U value of a flat roof To comply with Part L of the building regulations 2010, all roofs to rooms (except those in unheated buildings) should be thermally insulated to a maximum U-value of of 0.18 W/m²K. As for insulating below the joists, an insulating laminate (insulation bonded to plasterboard) such as Celotex PL4000 or a separate rigid PIR insulation board finished with a separate sheet of plasterboard can be securely fixed to the joists to provide an internal finish to the roof. If you're unsure as to the difference between warm roof insulation and cold roof insulation, keep reading. As mentioned below the only Flat Roof Insulation that we install is the Aerolite 135mm or the Isotherm 145mm. How are flat roofs defined? The Saint-Gobain Insulation UK U-value calculator gives you instant access to calculating a proposed insulation thickness and product options or giving an indicative calculation on a … Whether ballast or green roof is chosen, a filter membrane is a good idea just beneath it, to prevent dirt clogging up the drainage channels. The thickness of the insulation will be governed by the depth of the joist and this may not allow sufficient insulation to meet the regulations. According to the Energy Saving Trust, a quarter of heat is lost through the roof in an uninsulated home. A cold roof has the insulation placed below the structural deck, which thus remains cold. Cold roof insulation is a cheap way of insulating outbuildings, although it typically requires the addition of a roof void ventilation system to prevent the accumulation of damp. More importantly, they have excellent thermal properties and compressive strength, which makes them ideal for flat roof insulation. Knowing the difference between a warm deck roof and cold deck roof can certainly make life easier. SuperHomes are older homes refurbished by their owners for much greater comfort, lower bills and far lower carbon emissions – at least 60% lower! The insulation material is placed between the supporting joists, leaving a gap of 50-60mm between the roof and insulation. A green (sedum or grass) roof can also be put onto a flat roof, provided it can take the weight. Flat roof insulation £50 – £100 per m². 4 0 obj Flat roofs are notoriously poor insulators. Insulation can also help to limit condensation and contribute to acoustic insulation (depending on the type of insulation used). Used within a Bauder waterproofing system our products meet current UK Building Regulations Part B for fire protection.. I've built a timber frame to support a new plasterboard ceiling below the existing one. In most pitched roofs any existing insulation is likely to be between the ceiling joists and where this reaches the top of the joists, the new insulation should simply be laid across the joists at right angles. David is Manager of Green Deal Advice and author of Sustainable Home Refurbishment: The Earthscan Expert Guide to Retrofitting Homes for Efficiency, SuperHomes © 2021 Insulation can either be put below the weather proof membrane, which is called a ‘warm roof deck construction’, or above the waterproof membrane, which is called an ‘inverted warm deck’. © David Thorpe Jan 2013. I'm about to have my flat roof re-covered because its at the end of its service life. I want to Insulate below a flat roof without removing the existing ceiling. Rigid PIR insulation boards, such as Mannok Therm Roof / MR boards, are generally the preferred roof insulation materials for flat roofs for a number of reasons.They are lightweight, easy to fit and come in a range of thicknesses. Waterproofing: Single ply membranes made of materials such as rubber, thermoplastic or elastomeric are the most effective and should extend up adjacent walls at least 150mm from the roof surface. 10M Plus: R22, Thickness: 10mm (0.4") closed cell polyethylene foam covered on both sides with reinforced reflective foil.. 5M Plus: R17, Thickness: 5mm (0.2") closed cell polyethylene foam covered on both sides with reinforced reflective foil. Putting it on top of the roof helps to prevent thermal bridging, and keeps the thermal mass of the structure on the warm side. A single ply EPDM or TPO membrane may be used, which is easy to lay down. Saint-Gobain Insulation UK manufacture and supply glass mineral wool slabs and rolls along with rigid Polyisocyanurate (PIR) boards that can be considered suitable for a wide range of applications across flat roofs whether you’re looking to insulate at joist level or above the roof deck in your flat roof … Flat roof. endobj Limited by guarantee Flat roofs, for example on extensions, bathrooms and dormer windows, are not the best of ideas. Warm Roof vs Cold Roof. If you are replacing a flat roof, then it’s worth seriously considering a pitched roof. Secondly, it’s important to understand how to keep it airtight and prevent condensation. Here are three general types of systems you can put on a flat roof:1. There are three recognised designs of flat roof construction; warm, cold and inverted. Cold roof insulation involves insulation installed at the floor level of the loft, it’s generally used for storage/ unused loft spaces where the loft doesn’t need to be warm. Multifoil layers are a good alternative to sheet insulation if your rafters are too thin. Roof Insulation For Sale - Prodex Total. But where? Most of the traditional flat roofs belong in the “cold roof… Warm deck: the type of insulation for this is usually of a rigid type and the thickness will … The waterproof layer is above the insulation and a vapour control layer is placed below the insulation. This is best done when the roof … Some forms of roof decking may also have insulation bonded to them. Cold Flat Roof: Many properties use this option, as there are no additional costs for scaffolding or organising how to gain safe access to the roof exterior. It should be lapped up around the insulation and affixed securely to prevent any air infiltration. You need to insulate a flat roof. Included in this Group: 48 inch, Fast Action, 72 inch, 24 inch, and 16 inch. This method of insulation can also be used to upgrade the thermal performance of an existing roof … On top of that, there’s the insulation layer, the roof construction and the roofing. 0.025 W/mK (80 - 119 mm) 0.024 W/mK (≥ 120 mm) High performance PIR insulation with coated glass tissue facers. This would give a U-value of around 0.21W/m2K. cold deck: this is where the insulation is placed between the joists/rafters or in between the ceiling joists in the case of a pitch roof. A typical warm roof is shown in the sketch below. When it comes to insulating a flat roof, there are two options. The external wall insulation needs to be extended up to the underside of the roof insulation to prevent cold bridging. Now you might say, why not put the insulation under the ceiling? Warm deck: the type of insulation for this is usually of a rigid type and the thickness will … Typically, you leave a gap for ventilation, as condensation may form that can lead to rot. This is easier to insulate and to maintain. The roof probably is the most important element of the outer skin of a building to provide protection against weathering. Our insulation solutions for flat roof applications provide both excellent fire and acoustic performance in addition to high levels of thermal performance. To achieve this, add 100 to 160mm of insulation above the structural deck (dependant upon insulant conductivity). A cold roof has the insulation placed below the structural deck, which thus remains cold. It can be used with roofs covered in bitumen sheeting or metal sheet, or green roofs with diffusion resistant exterior cladding. Different insulants have different efficiencies and performance levels which affects the thickness required to meet building regulations. endobj by Mark Row. It generally is used for storage or unused loft areas where the loft doesn’t need to be warm. National Energy Foundation It takes the form of reinforced bitumen sheeting or polyethylene laminated with metal foil to reflect the heat back in. Cold roof insulation. Entry is free. The chosen insulation laid on top of this should be able to take the weight of anything put above it on the roof without compression, or protected from compression by further sheeting. For more detailed guidance on roof insulation please google for the following Energy Saving Trust literature: Thanks to the Energy Saving Trust for the illustrations. In BS 6229, a roof is defined as flat if it has an overall pitch of 10 degrees or less. A flat roof should be designed to minimise condensation and a condensation risk analysis should be undertaken taking into account positioning of insulating materials, vapour control layers, ventilation, thermal insulation and the choice of materials. Supporting joists, leaving a gap of 50-60mm between the flat roof it is for... 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