Twin Skin Metal Cladding
URSA HOMETEC Cladding Roll is suitable for walls and roofs in twin skin metal cladding and similar systems.
Three grades of URSA HOMETEC Cladding Roll are available;
URSA HOMETEC 40 Cladding Roll - thermal conductivity 0.040 W/mK.
URSA HOMETEC 35 Cladding Roll - thermal conductivity 0.035 W/mK.
URSA HOMETEC 32 Cladding Roll - thermal conductivity 0.032 W/mK.
The bracket and rail system used in twin skin metal cladding introduces a considerable amount of thermal bridging. The brackets should therefore incorporate a thermal break to minimise this effect.
Limiting air infiltration and minimising the risk of interstitial condensation can be achieved by sealing the laps of the inner lining sheet, incorporating a vapour control layer and sealing around gaps and service penetrations in the roof or wall. It should be noted that most metal clad roofs will suffer from intermittent condensation problems on clear, cloudless nights due to clear night sky radiation. If considered harmful a breather membrane should be used over the insulation to drain any condensate away to the gutters.
Metal clad roofs are relatively lightweight so have a poor acoustic performance and will readily transmit sound from external sources and rain or hail falling on the roof. The inclusion of URSA HOMETEC Cladding Roll will improve the acoustic performance considerably increasing the sound reduction from a typical 30dB (uninsulated) to almost 50dB when incoporating 200mm of URSA HOMETEC Cladding Roll. Internally these buildings can suffer from poor acoustic performance due to excessive sound reverberation. A perforated liner tray should be used to allow the sound energy to be dissipated by the mineral wool within the structure.
With increasing levels of insulation it is vitally important avoid thermal bridging; ensure continuity of the insulation around openings and at the junction of elements.
Further design guidance on all of the above is contained in the technical design guides available from the Metal Cladding and Roofing Manufacturers Association (MCRMA).