An introduction to UNRIVALLED INSULATED RENDER PERFORMANCE

Transcription

1 An introduction to UNRIVALLED INSULATED RENDER PERFORMANCE

2 An introduction to CONTENTS PAGE 2 Introduction 3 FOAMGLAS W+F Slab 4 Water Resistance 5 Re-cycled and sustainability 6 Finishing options 7 Impact resistance 8 Flood resistance 9 Fire 10 Technical information The façade of a building is far more than an aesthetic effect it fulfils a variety of functions, all of equal importance to the performance of the structure as a whole. Lime is the oldest construction mortar known to man used to bind together and coat walling forms made from stone, brick, straw and earth. Lime is experiencing a renaissance due the modern methods of production that have erased the common perception that it is an archaic process, fraught with risks in handling, unreliable set and low strength. A traditional aesthetic created with natural minerals The LIMETICS insulated render façade system introduces a new dimension for insulated render performance, sustainability of source and building life maintenance costs. By combining the unique properties of 66% recycled cellular glass insulation with natural hydraulic lime render we have created a system that is impervious to water, inert, non-combustible; resistant to flooding and provides an impact resistance similar to a thermal masonry unit. If damage does occur to the render the thermal performance of the system is unaffected and water penetration is not at risk. LIMETICS brings the Telling Lime Unilit range of hydraulic mortars together with FOAMGLAS recycled cellular glass slabs developed by Pittsburgh Corning. Proven in use in the UK climate for in excess of fifteen years the system has been tested at the Taylor Woodrow laboratories to gain a CWCT performance certificate and flood prevention assessment. The primary function of a façade as being for the protection of the inhabitants from the effects of the climate has radically changed, as today it must also create an internal environment that is healthy, air and watertight meet ever improving standards of thermal performance offer a pleasing architectural aesthetic within its environment be from a sustainable and recycled source contribute to targets for carbon neutrality be compatible with modern methods of construction comply with current national building codes be affordable over the life of the building demonstrate low maintenance costs and a year life expectancy These are the performance benchmarks that inspired the birth of the LIMETICS system of FOAMGLAS and Unilit Hydraulic Lime mortars. The system is installed by established contractors selected due to their having retained traditional plastering skills and combined them with cladding. 2

3 FOAMGLAS W+F SLAB INSULATION OF EXTERNAL WALLS WITH LIME RENDERS - NEW BUILD OR RENOVATION Use of FOAMGLAS Foamglas W+F is an ideal insulation for use on exterior walls. Being totally impervious to water and water-vapour, the potential for penetration of water through the external wall construction is eliminated and excellent insulation values are achieved. Foamglas does not deteriorate with age, ensuring that the thermal performance values remain constant throughout the life span of the building. Foamglas is rigid and dimensionally stable, it does not shrink or warp with the effects of climatic variance. With its low coefficient of expansion (approximately that of concrete) there is no risk of joints between the slabs opening up. Foamglas is totally non-combustible and neither contributes to fire nor gives off toxic fumes or smoke; it is totally free from HCFC, HFC and pentane. Creates an insulation envelope around the building minimizing the effects of cold bridging High density insulation adds to the thermal mass and slows thermal inertia particularly when combined with blockwork plastered internally with lime mortar. Applications For the thermal insulation of exterior walls for residential and commercial premise. Foamglas is suitable for buildings constructed in concrete, brick, timber (with a cavity) and lightweight steel. Specification Guide The thermal insulation slabs of 600mm x 600mm x., are made of alumino silicated 66% recycled cellular glass composition having a density of 105 kgs per metre cube and a thermal conductivity of 10ºC of k = W/mK The selection of the fixing method is determined by the style of construction, the use of the building and the anticipated humidity levels. For buildings of high humidity and for underground use, a cold bitumen adhesive PC56 is recommended. For concrete structures in both new construction and refurbishment, a cement based adhesive PC164 is more suited and in restoration of old solid wall buildings a hydraulic lime mortar Unilit K ensures continued vapour permeability. Surface irregularites in excess 5mm over 2mm will require that the walls be levelled with an appropriate render layer, the thickness and type of adhesive adjusted or the adoption of the mechanical cramp fixing method. This method also applies to application on to lightweight steel/timber backgrounds as well as in soffit conditions. It is proven that Foamglas and Unilit hydraulic lime renders do not allow the passage of moisture but the most typical point of failure of claddings lies in the interfacing and seal detailing and these should be detailed and supervised during construction. See technical detail drawings The Foamglas exterior wall insulation system can be applied by qualified plastering contractors holding cladding expertise and a list of recommended contractors is available upon request. Brick or blockwork FOAMGLAS W+F Slab Bonding layer Unilit 15 P2 Glass-fibre reinforcing mesh Lime render finish Building Regulations, Part L & J All FOAMGLAS systems meet the requirements of Building Regulations, with regard to air tightness of the building, the avoidance of cold bridging and sustainable construction. FOAMGLAS systems will continue to fully perform for the lifetime of the building. 3

4 An introduction to RE-CYCLED & SUSTAINABILITY CARBON NEUTRAL FOR PROTECTION OF THE ENVIRONMENT The FOAMGLAS insulant is a dense cellular glass slab, manufactured from 66% recycled glass. FOAMGLAS has a global warming potential of less than 5. Harmful CO2 emissions are acknowledged as being a major cause of the greenhouse effect occur during the production of both cement and lime. However with lime burnt at temperatures of circa 900 C and cement exceeding >1450 C, more energy is required for the production of cement. Additionally, a study of the lime cycle reveals that an equal amount of CO2 is retained during the carbonation/setting process of the plaster as is released during the burning of limestone. As a consequence lime mortar is by far the more ecologically preferable product. 4

5 FIRE ABSOLUTE FIRE RESISTANCE FOAMGLAS W & F cellular glass insulation provides unrivalled fire protection and is non-combustible to Euro Class A1 no contribution to fire. Due to the slow transfer of heat through the closed cell insulation, an external fire will have less impact upon the building structure. Fire breaks are not required in the Limetics system although if a drainage cavity is created behind the insulation to meet NHBC requirements then cavity fire barriers will be a needed as with all systems of external wall insulation. Many building insurers have rejected the use of plastic foam insulations irrespective of their claims for Class O surface spread of flame and non retardant grades, as they are largely combustible and create significant fumes, smoke and gas. There are no resin binders for fibres compaction. For internal fire compartment walls, subways, soffits and linings LIMETICS offers a non combustible and waterproof walling solution that can be tiled, directly decorated or pre-coloured as a render finish. 5

6 An introduction to FINISHING OPTIONS ISN T IT TIME YOU RETURNED TO LIME? Using a modern day manufacturing process, the Limetics range of natural hydraulic lime finishes replicate the characteristics of historic mortars in strength, porosity, adhesion and flexibility The strength of the mortar is controlled by the ratio and sizing of sand to the lime mix and there is a optimum compatability of mineral bond between the mortar and the FOAMGLAS. The abrasive surface of the cellular glass slabs eradicates the need for synthetic impermeable binders. The Limetics systems offer a comprehensive range of finishes available in a variety of textures and colours to maintain the flexibility and porosity of the mortar. The hydraulic lime render can create traditional Stucco effects without synthetic texture or colouring. Traditional render features in ashlar grooves and struck joints can be formed. Compatibility throughout the decoration and plaster systems ensures many years of resistance to deterioration. The products are suitable for internal and external use. The Limetics system is suited to building without expansion and movement joints as the open pore structure creates inherent flexibility and significantly reduces movement caused by thermal gain. The Foamglas is dimensionally stable and does not cause the build up of stresses within the render coats. Simulated stone effects in render can be achieved in styles of Portland, Coral, limestone and sandstone 6

7 IMPACT RESISTANCE WORKING TOGETHER MAKES US STRONGER A FOAMGLAS cellular glass slab bonded to a stable substrate will provide the characteristics in impact and sound resonance of a thermal masonry unit when rendered with Unilit Natural Hydraulic lime. The LIMETICS system passed the soft body and hard body impact tests under the CWCT test criteria. Should the façade ever be punctured or receive an impact such that the insulation was exposed it provides a risk neither to fire nor water ingress. There is no requirement for increased thicknesses of render, additional mesh reinforcements or overlaid sheets to enable the system to offer these characteristics of resistance to impact. 7

8 The closest comparison of the Limetics render to a mineral would be natural stone. Mined from a limestone of a specific source with naturally occurring clay deposits the processed lime when mixed with sand and when water is added, reacts with air to turn itself back in to a natural mineral. There are no synthetic additives. As with stone, hydraulic lime performs as well when immersed in water as when not and dries naturally. The CWCT tests upon the Limetics system demonstrated its ability to perform as a protective and decorative coating for a cladding but this came as no surprise as hydraulic lime has protected buildings for centuries. The open pore structure ensure the render finishes are unaffected by frost and in the event that water should penetrate the impervious cellular glass insulation slab is a waterproof layer that repels the moisture and it will simply dry out. The hydraulic lime mortars will like stone change change colour when they are wet and return to their original form when they dry. WEATHERING NATURAL STONE APPLIED ON SITE 8

9 FLOOD RESILIANCE A NATURAL CURE TO A NATURAL PROBLEM For modern methods of construction the LIMETICS system was tested at the Taylor Woodrow Laboratories as an insulated cladding capable of providing resilience to flooding. The combination of Foamglas recycled cellular glass insulation and hydraulic lime were subjected to a unique regime of testing to establish the resilience of the system to flooding when applied upon a panel of lightweight steel walling immersed under a one metre head of water for a 72 hour period. There is a study programme headed by a CIRIA consortium to meet the challenge for resistance and resilience of buildings. Its aim is to determine how the implications of flooding may be mitigated by best practice in material selection and construction techniques and that by laboratory and field testing their findings should influence building regulations. The LIMETICS system provides one such innovative solution and in flood plain areas a waterproofed hydraulic lime can be selected to ensure that ingress of floodwater through the walls and deterioration of rendered surfaces by foul water contamination is avoided. Unilit natural hydraulic lime has been successfully used in this remedial process and benefit has been gained by the increased awareness of a natural process for repair that will offer resilience and offer best economical value. 9

10 An introduction to FOAMGLAS FOR WALLS FOAMGLAS W+F SLAB Thickness of FOAMGLAS W+F Slab The table opposite gives the mean overall U-values obtained for various Foamglas thicknesses, which can be used in a variety of situations, without risk of interstitial condensation according to the following design critera: - internal temperature <_ 20ºC - internal relative humidity <_ 55% - external temperature >_ -10ºC - internal finish in traditional plaster Storage of the Insulation The cellular glass slabs should be dry during application. For this reason the Foamglas packs should be protected from the weather or poor site conditions and should be stacked on edge and clear of the ground. Adhesives Foamglas W+F Slab is bonded direct to the wall using cementatious adhesive PC164 or PC56 cold bitumen adhesive. The adhesive is applied to the whole surface of the W+F Slab using a 10mm notched trowel. Supporting structure Overall U-values for various FOAMGLAS W+F Slab thicknesses (W/m 2 K) Type Thickness mm Solid brickwork Heavy concrete block Medium concrete block Lightweight concrete block * Brick / 50mm cavity / brick 100 / Brick / 50mm cavity / lightweight 100 / * concrete block In-situ cast concrete No fines concrete Profiled steel *Joints need to be sealed Render Finish The hydraulic lime render finish is available in 12 through-colours and in textures to allow different finishes; it is available from Telling Lime Products or from builders merchants nationwide. Telling Lime Products are available in a wide range of colours and finishes, including: - Fine textured or smooth finishes - Medium textured finishes - Coarse textured finishes - Polished marble finishes Comprehensive information and colour charts are available from Telling Lime. 10

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12 Previous Clients Restoration Projects Dover Castle, Dover, Kent Osborne House, Isle of Wight Bath Spa, Bath Map-a-Mundi, Hereford Cathedral Noah s Ark, London Bishops Palace, Lincoln St. Nicholas Church, Plymouth Silchester Roman Church, Hampshire Chichester Cathedral St Paul s Cathedral Houses Of Parliament, London New Build Projects Magdalen College, Oxford New Bond Street, London Charing Cross Police Station Preacher s Court, London Old Palace School, Croydon Wyvern Sixth Form College, Weston Super Mare Urquhart Castle, Inverness Loch Lomond Visitor Centre Windsor Castle Visitor Centre Lower Leas Coastal Park, Folkestone Royal Hospital, Chelsea Telling Lime Products Limited Primrose Avenue Fordhouses Wolverhampton WV10 8AW Tel Fax Internet info@telling.co.uk