Knauf Insulation, the UK’s leading manufacturer of insulation products, and the only producer of four types of insulation: glass and rock mineral wool, extruded polystyrene (XPS) and extruded polyethylene (XPE), can announce that Crown DriTherm full fill cavity insulation is the only insulation solution able to achieve a U-value of 0.27 (the minimum permitted in 2006’s revised Building Regulations) in a 100mm cavity in a dense block construction. Crown DriTherm full fill cavity insulation, which is EcoHomes and The Code For Sustainable Homes compatible, is the only range of products which can be used within all block constructions – dense, medium dense, standard aircrete and lightweight aircrete.
Crown DriTherm Cavity Slab 32 has a thermal conductivity of 0.032 and when installed in a full fill application can achieve a U value of 0.27 with a 100mm cavity. Because the product can be installed in full fill there is no wasted space in the cavity. Products with lower thermal conductivities than Crown DriTherm 32 are available, such as rigid PIR and Phenolic boards, but these require a thickness of 60mm or 55mm respectively alongside a 50mm unventilated airspace to match or exceed this performance which obviously adds up to more than the 100mm required for Crown Dritherm Cavity Slab.
Rigid Boards cannot be installed in a full fill application and require a clear residual cavity to ensure that the insulation will not allow liquid water to bridge the cavity from the outer to inner leaf. Approved Document C (Site preparation and resistance to contaminants and moisture) 2004 and NHBC Standards require that this clear residual cavity is a minimum of 50mm in all but very severe exposure zones where the requirement is for a 75mm if fair face masonry is used. All Crown DriTherm Cavity Slab products are treated with silicone to ensure that the product will not allow the passage of liquid water when the product is used in full fill. Approved Document C will allow full fill to be used in very severe exposure zones with fair faced masonry provided the cavity (and insulation) is a minimum of 150mm thick, however NHBC standards will not allow full fill in these circumstances.
Crown DriTherm Cavity Slab is also extremely competitively priced and offers a range of solutions to meet most people’s requirements and pocket. Using calculations based on a standard domestic dwelling (based on an average of 100m² of opaque wall area with 100mm cavity and U-value of 0.27) Knauf Insulation’s Crown DriTherm Cavity Slab full fill insulation systems can save on average £1.79 per m² compared to PU/PIR part fill cavity boards. Add this to installation costs (it is generally accepted that installing part fill cavity boards takes longer and costs more than installing full fill mineral wool cavity batts), using Crown DriTherm can save approximately £280 per standard dwelling built with lightweight aircrete blocks with a 100mm cavity.
Cost is further reduced using Knauf Insulation’s innovative Supakube delivery system which uses advanced compression technology and strong packaging materials, which ensures the product is not only easy to store but can be delivered more efficiently saving time and reducing carbon emissions from delivery vehicles as more product can be loaded onto each lorry.
Furthermore, the entire Crown DriTherm full fill range is classified as Zero Ozone Depletion Potential (ODP) and Zero Global Warming Potential (GWP) as outlined in The Code for Sustainable Homes and EcoHomes, which means that they are suitable for the production of zero carbon homes. Crown DriTherm, as supplied by retailers such as Travis Perkins, offers an environmentally sound solution to carbon emissions in line with the Government’s Energy White Paper ‘Our Energy Future – Creating a Low Carbon Economy’, which highlighted the need to reduce carbon emissions by 60 per cent from their levels in 2003, by 2050.
Phil Rigby, Insulation Academy Manager at Knauf Insulation, said: “ Crown DriTherm Full fill cavity insulation not only saves money and labouring costs during installation, but it also provides fire resistance to the building unlike other cavity insulation products available on the market. Crown DriTherm offers an insulation solution for every type of construction, which is something no other manufacturer can boast!”
Crown DriTherm Cavity Slabs are semi-rigid or rigid slabs of non-combustible, glass mineral wool with a water-repellent additive. They are 455mm wide to suit standard vertical wall tie spacings, ensuring a closed joint with adjacent slabs.