Transcript Document
A Guide to Solid Wall Insulation Agenda • Introduction • Solutions • Internal Solutions • External Solutions • Summary • Questions Introduction – The facts about Hard to Treat Homes • HTT homes account for 43% of stock but actually emits over half the CO2 from all homes. • Over half of the HTT stock is in the private sector. • 65% of PRS is HTT Introduction – The facts about Hard to Treat Homes • HTT properties tend to be more difficult and expensive to improve in terms of providing adequate insulation and heating. • Over 50% of fuel poor households live in HTT homes • There are around 9.2 million dwellings that can be considered HTT (43% of the housing stock) • 6.6 million properties have solid walls (31% of the total housing stock) • Of the 326,000 high rise flats in England 48% have solid walls. Introduction - What is a Hard to Treat Home? These types of property often fall into one or more of the following categories: • Solid wall construction • No loft space • Off the mains gas network • Non traditional construction • Non standard cavity Introduction - What is a solid wall? • 9” masonry walls and other non-traditional construction types such as single leaf masonry, >9” walls (e.g. thick stone walls) • concrete walls, metal or timber panels and some mixed wall types (e.g. Where the ground and first floors are constructed of different materials) • BRE estimate that around 7% of unfilled cavity wall stock cannot receive CWI. • High rise flats (at least 6 storeys high) – esp. 1953-1972 Introduction - What is a solid wall? • Hard to treat not really…. expensive to treat as opposed to loft and cavity • Solid wall solutions • Internal and external Internal Wall Solutions Rigid boards Internal DryFlexible Lining(Filled (Direct (On Straps) Fix) Internal Dry Lining Studs) External Internal Render Lining System Internal Wall Solutions What are the solutions? Typically consists of either dry lining in the form of flexible thermal linings available in 1 metre by 12.5 metre rolls, laminated insulating plasterboard (known as thermal board), or built-up systems using fibrous insulation such as mineral wool held in place using a studwork frame. Flexible thermal lining Rigid board Internal Wall Solutions Case Study – Flexible thermal lining SEMPATAP The problem A solid wall Victorian terraced uninsulated converted loft space. property with an The solution Sempatap is thermal insulation on roll which is applied like wallpaper and at only 10mm thick does not cause significant disruption during installation. This product can be applied to ceilings as well as walls and provides a solution for properties without a loft space as well as those with solid walls. It can also be applied to the underside of floorboards in a cellar/basement. Internal Wall Solutions Case Study – Flexible thermal lining Internal Wall Solutions Case Study – Flexible thermal lining The product is applied using a special adhesive using a roller or brush and can be easily cut to size using wallpaper shears or scissors. Once the product has been applied it can be painted, papered or even tiled. The manufacturer of this product expect it to have a life expectancy of 30 years. Due to the flexibility of the product it can be used on uneven walls and irregular surfaces and can be used on sloping walls and ceilings in converted loft spaces. The product is only applied to the exterior facing interior walls of the property. Internal Wall Solutions Training and time frames (Flexible thermal lining) SEMPATAP TRAINING – On site training is provided for all contractors in the application of Sempatap Thermal – On site training is always preferred as it covers a real life installation and the difficulties that can be encountered – The trainer acts as part of the installation team for the period of training – Training is carried out on site and frequently takes place in occupied properties. SKILLS – Sempatap Thermal is not difficult to apply, the skills required are similar to a decorator/wallpaper hanger or dry lining contractor Internal Wall Solutions Case Study – Rigid boards SPACETHERM The problem Continuity of the existing cavity fill missing in places and dampness. • Damaged external render led to damp inner wall surfaces • Internal damp led in turn to cold spots and mould growth • Cold bridging at door/window lintels The solution Aerogel insulation was laminated to Fermacell. The existing lath & plaster was removed and the thermal laminate fixed directly through the board to the existing brick. Internal Wall Solutions Case Study – Rigid boards Internal Wall Solutions Case Study – Rigid boards The solution • No specialist contractors required • Can be installed room-by-room with tenants in situ • Does not require upgrading entire blocks at once • Increases internal surface temperature • Improves response to heating input when heated intermittently • Lowest thermal conductivity available (0.013 W / mK) • Hydrophobic, allowing installation on damp substrate without drying periods • Integrated foil layer, reducing condensation risk on solid walls • Fermacell wallboard allows fixing of units, radiators, etc to inner surface, reducing cold bridging Internal Wall Solutions Case Study – Rigid boards Internal Wall Solutions Training and time frames (Rigid boards) SPACETHERM • • • • • • • No specialist skills required- tradesman level Training can be given on first installation with some systems Final surface may need plaster/tape and filling depending on client preference Depending on the system, will be screwed or dot and dab Installation time of an average 3 bedroom semi is 2.5 days for 2 man team after preparation work Price depends on system and thickness but is around £10- £55/m2 Ancillary costs of skirting boards, sockets etc. Internal Wall Solutions Site supervision and surveys • • • A survey of the property is required to assess the suitability of the substrate and assess any ancillary work required Supervision will vary depending on the system Low level of supervision required with most systems External Wall Solutions What are the solutions? Comprise of an insulation layer fixed to the existing wall, with a protective render or decorative finish. Dry cladding offers a wide range of finishes such as – timber panels, stone or clay tiles, brick slips or aluminium panels. External Wall Solutions Why Externally Insulate? • To meet the Decent Homes Standard - A decent home is windproof, weathertight and warm, with modern facilities - The Government expects all homes to meet this standard by 2010 • Increases thermal quality of the building - Particularly relevant when refurbishing non-traditional housing • Overcomes moisture/condensation issues • Protects the existing building envelope • Reduces heating bills by 25% • Improves the building’s appearance External Wall Solutions What is External Wall Insulation? • A method of upgrading the thermal performance and external appearance of existing properties • Insulated and rendered properties are transformed into warm, energy efficient and attractive homes/buildings Before After External Wall Solutions External Wall Insulation – Key Components • Beads and closures • Insulation • Fixings • Reinforcement layer • Base render coat • Finish coat External Wall Solutions Choice of Insulation – Comparative Performance Insulation Properties: EPS Mineral Phenolic Cork Wool Thermal Conductivity w/m2k 0.037 0.036 0.020 Fire Performance Emissions Production Recyclability x x x Impact Resistance Cost PIR 0.038 0.028 Key: = Excellent, = Good, = Adequate, X = Poor External Wall Solutions Rendering options • Hand applied base coat • Hand applied finish coat • Machine applied one coat • Brick slips External Wall Solutions Finishes available Mineral render scraped texture Dry dash using 6-8mm coloured aggregate Brick slips or brickeffect render Spray roughcast Light synthetic aggregate using an acrylic binder External Wall Solutions Upgrading Housing Stock • Common Property Types – – – – – – – – – – – – Myton Swedish Timber Tarran BISF Reema Wimpey No-fines Unity Easiform Spooner Airey Solid Brickwork Traditional Masonry Cavity External Wall Solutions Benefits of External Wall Insulation for Solid Walls • No internal living space is lost • Minimum disruption involved – decanting of residents not required •Condensation risk moved to outside of system – structure stays warm and dry •Low u-values achieved saving carbon emissions and energy costs • Minimal maintenance once installed •Equally suitable for low and high rise schemes with funding available