PRX-RS04 - Built-up Metal Roof System Last verified by manufacturer 8 months ago Viewing archived product data This product has been archived and is no longer available for project specification within NBS . Archived data may not reflect the manufacturer's most current version of the product. I am happy to view archived product data and understand that such data may not reflect the manufacturer's current version of the product. Confirm and view product data U Value 0.18 W/m²K | System Depth: 259 mm Firth Steels Ltd Variant: U Value 0.18 W/m²K | System Depth: 259 mm