This unique Concealed Fix system is commonly known as a standing seam system. This is one of the only Concealed Fix systems where the sheet can be tapered, as well as machine curved and reverse curved.
Zip-Tek 440 is similar to Zip-Tek 420 but wider and incorporates transverse stiffener ribs in the pan. Please note, Zip-Tek 440 is only available for exports, SADC and African countries. There are not many Concealed Fix profiles available for site rolling in Africa and GRS’s mobile mill resolves this problem.
Is roll-formed from certified steel complying with (select from steel column in above table). The profile shall have a male and female upstand with an upstanded height of 68 mm which will provide a capillary brake. The nett effective cover width will be 424 mm. The male head shall be smaller than the female head.
It is recommended that Zip-Tek 420 sheeting should be laid by an approved contractor in strict accordance with manufacturers specifications. When using a GRS (Brownbuilt) Approved Contractor, a five year guarantee on site-workmanship and watertightness may be issued after approval by Global Roofing Solutions (Pty) Ltd.
Stop endings must be formed at the apex and the pan turned down at the eaves to form a drip. The roof sheeting shall be closed as necessary with purpose made flashings of a design approved by the supplier. These flashings shall be notched around ribs where necessary. All these operations must be performed with special tools available from the supplier.
All Zip-Tek 420 material should be suitably supported under cover until required to be hoisted into final position.
The completed roof, including gutters, must be handed over free of any swarf and other debris.
The manufacturer shall be assessed and certified as complying with ISO 9001:2008 Quality Management System
Zip-Tek 420 is available ex-factory in sheet lengths limited only by transport restrictions, normal loads 12.5 m and abnormal loads 18.6 m. Longer lengths can be milled on site, obviating end laps which are not recommended. End lapping negates the concealed fix concept and no water tightness guarantee can be issued. End lapping, due to corrosion, reduces the life expectancy of the roof.