Since April, manufacturers and product associations have been busy redeveloping systems and publishing guidelines to help you comply with changes to energy-efficiency regulations. Here's a rundown of the latest to make the roofing specifier's life easier 鈥�
  • Insulated roof and wall panels manufacturer Ward has recently published construction details and guidance to the regulations. The guide includes the insulated panel thicknesses required to meet the new Part L. It also looks in depth at thermal bridging, thermal insulation, air leakage, insulation continuity and thermographic imaging.

    Much of the guide contains approved construction details of Ward's roofing systems, including the ridge detail of its IP1000 roof system (see diagram, above). This shows how specifiers must use air seals and extra insulation to ensure the roof is airtight. Ward's sister company Kingspan Insulation has also published new approved details and SpeedDeck has a preliminary set of details available for specifiers.

  • The National Association of Rooflight Manufacturers has published an eight-page brochure on Part L and J, which it says will help to clear up the confusion caused by mixed messages sent out by manufacturers. For in-plane rooflights NARM recommends that designers should specify triple-skin rather than double-skin systems. It also states that designers should specify rooflights with a standard U-value of 2.2 W/m2K, even if Part L allows a higher level, where solar gain requirements restrict rooflight coverage to 12%.

    The brochure has a section on determining adequate daylight hours, which the approved Part L document does not. From data in the brochure, specifiers can find out what area of rooflights is required to achieve desirable levels of daylight in factories, storage buildings and recreational buildings. The document also discusses thermal bridging, solar overheating and carries typical designs of in-plane rooflights that achieve U-values laid out in Part L.

  • Several manufacturers are launching roofing products they claim will prevent designers and specifiers having to change the way they work. British Gypsum-Isover says that its new Isowool Frame Batt HP meets new U-value targets for warm roof construction without the need to increase the depth of rafters or use excessive thicknesses of insulated plasterboard.

    Isowool Frame Batt HP fits between rafters and, depending on overall roof construction, may need just a single thickness of standard Gyproc wallboard to complete the ceiling. It is available in five standard thicknesses and is designed for use in vertical, horizontal and sloping details in frame structures.

    In response to the new air-leakage requirements for industrial buildings of more than 1000 m2, Ejot Ecofast has added Polyband air and moisture barrier tape to its range of roof-fastening products. The company says the tape is an effective way of sealing the metal lining layer at joints and at all junctions and openings.

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