Aluminium with factory applied moisture barrier

In any insulation system one of the key components is the outer cladding also referred to as jacketing or lagging. One of the most widely used materials for this outer metal jacket is Aluminium, light weight, durable, easy to form and cost effective. Its aim is to keep the insulation and piping free from damage, water ingress while keeping up a respectable appearance in often challenging envi­ron­ments.

Its ease of forming make's it the ideal metal to work with alongside its resistance to corrosion. It can have a smooth plain finish or a stucco effect to both add rigidity and potentially hide any scuffs or light damage.­  For either aesthetic reasons or to improve emissivity an outer coating can be added the popular ones are Polyester for simply colouring or PVDF to really improve emissivity and durability, or for the best overall performance in terms of the highest emissivity with resistance to delamination or abrasion damage a PVF is best in particular a Tedlar® coating. The high emissivity coatings will signi­fic­antly improve personal protection and reduce the insulation thickness for the same performance.

One area often overlooked is the underside of the Aluminium which can be prone to corrosion. Its often difficult to prevent water ingress into an insulation system as a result water can be trapped under the aluminium, on top of the internal vapour barrier protecting the insulation. This gap is quite small and almost acts like a crevice, any chlorides either in the water or from materials within the system can contribute to crevice or pitting corrosion. This is often undetected until its too late resulting in expensive shutdowns and costly replacement jacketing.

The solution is Drymet a factory applied moisture barrier combining three layers made up of two layers of polythene with a middle layer of Surlyn® all tightly bonded together and joined to form a permanent layer on the underside of the metal. This product is often referred to as Poly Surlyn® due to the materials used. The Aluminium is just as easy to form and install but gives the long lasting dry Aluminium thus preventing corrosion. Drymet on the underside can be combined with a top layer of Coolmet (paint / PVDF) or Tedmet (PVF/ Tedlar®). BS Stainless are the only UK company manuf­ac­turing this product and can supply to projects around the world with accessory’s manufactured from aluminium to complement the jacketing such as rivets, toggle latches, banding and wing seals. Surlyn® and Tedlar® are both registered trademarks of Dupont™ who BS Stainless work with.

You can find out more about our range of Metal Jacketing including moisture barriers HERE

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