Steadmans - Roofing & Cladding Systems Details / Performance

Insulated Roofing - Wall Cladding Systems - Details - Performance

AS35 Insulated Panels

Description

AS35 Panels consist of 0.5 and 0.4mm sheets of hot-dip galvanised or Aluzinc coated steel, which can be finished with Plastisol, Nova or other polymeric coating. The weather sheet and liner are autobonded to a core of polyisocyanurate insulation to produce strong, rigid panels.

Thermal Performance

When installed, AS35 Panels provide a warm construction, with the whole building enclosed within the insulation envelope, so minimising thermal stress on structural elements. As there are no metal spacers or rails between the cladding sheets the panels provide continuity of insulation without repeating thermal bridging.

The polyisocyanurate insulation core has low thermal conductivity (0.019 W/mK) therefore U-values can be achieved with thinner panel depths than those containing less effective insulants: alternatively, depth for depth, AS35 Panels may be used to give substantially lower U-values and so improve the overall thermal performance of the building.

Long Term Performance

Long-term thermal performance depends on components retaining their design performance without any significant deterioration in the thermal resistance of the insulant.

Ageing: One of the key contributors to the high performance of Steadmans AS35 Panels is the zero-ozone depletion blowing agent which is embodied within the insulant's closed cell structure. The migration of the blowing agent from the insulant could, over time, result in a loss of performance: however, the metal faces of the panels prevent the diffusion of the blowing agent and ensure its retention within the insulation, so maintaining its thermal performance. The choice of blowing agent used in the manufacturing process maintain the panels' performance at all working temperatures.

Edge Effects: unsealed cut edges to panels can also cause a small amount of blowing agent loss: however, Steadmans' use of edge seals at panel junctions minimises the area of open edges.

Differential Movement: Rigourous quality control during manufacture ensures the insulation core is fully bonded to the metal facing panels and prevents delamination occurring as a result of differential expansion between the weather sheet or liner and the insulation. The thermal insulation core also reduces temperature fluctuations of the weather sheet. However, where high solar loads are anticipated the specification of a light coloured finish is advised.

Overall, the quoted U-values for Steadmans' panels make an appropriate allowance for ageing, ensuring the building will continue to benefit from the panel's excellent thermal performance.

U-values determined using finite element analysis to BS EN ISO 10211-1:1996 ‘Thermal bridging in building construction - Heat flows and surface temperatures Part 1. General calculation methods’ and following the methods and conventions in BR 443 ‘Conventions for U-value calculations’.

Wall panels covered by LPCB reference 635a/01, 635a/02 and 635a/03 must be laid vertically. Wall panels require external stitching at side laps at 300mm centres. Roof panels require external stitching at side laps at 450mm centres. Firefighter Plus panel requires site applied graphite tape. Contact Steadmans Technical Department for further details.