BS 8612 Testing Shows Klober Dry Verges at the Height of Their Powers

With the NHBC minded to make BS 8612compliant roofing dry verge systems compulsory for new builds sooner rather than later, Klober has put its Uni-Click and Contract dry verges through a variety of tests to demonstrate how both comply with the standard.

BS 8612 Dry-fixed Ridge, Hip, Verge and Valley Systems for Slating and Tiling defines tests to determine mechanical resistance to wind load and shows how specifiers should use data from these tests to verify whether a product is suitable or not, given the wind exposure of the location under consideration.

The standard also sets down a test for ridge-roll products to measure whether they can meet the profile of the roof tile at ridges and hips without breaking or splitting. A third test checks whether roof verges shed the water away from the surface of the wall, to avoid staining and damp issues.

Under the watchful eye of technicians at the company’s technical centre, both verge types were put through their paces. For the water leakage test both verge types were laid on the rain-screening rig in accordance with the manufacturer’s laying instructions using Redland Mini Stonewold concrete tiles at a batten gauge of 335mm (75mm headlap). They were tested in accordance with the standard, this being a pitch of 22° and a flow rate of 2l/min for a period of 10 minutes.

For the wind load test, an upward force was exerted on the tile adjacent to the verge via a wire attached to the tile. The force is increased slowly to replicate wind gusts and to test the mechanical fixing of the verge. In both cases the dry verge products easily performed to the satisfaction of the standard. In fact, in the mechanical resistance test, the tile adjacent to the verge snapped while the verge remained firmly fixed!

“Even though we knew Uni-Click and Contract to be BS 8612-compliant, it was pleasing to see these results: confirmation, if confirmation were needed, that Klober dry verges offer industry-leading performance,” says Andrew Cross, Marketing Manager.

Find out more about Klober’s dry fix ranges.



  1. I am a contractor for a number of house builders in the South East. This is a well written post, however one thing has niggled me since this new legislation has come out: all the usual roofing manufacturers have released statements about the new BS8612 and they have all in-house tested their product. I struggle to understand why it is not independently tested?
    I am currently using a product by a manufacturer I didn’t know did roofline products until 14 months ago and have sworn by them ever since. The product I am using is from Timloc. They have confirmed to me that their products are, and always will be, independently tested and not in-house. This, to me, gives far more clarity when it comes to the BS8612.
    I am surprised reading all the statements released from the major roofing manufacturers, as it all seems to be in-house or doesn’t directly state it meets the standard. I would appreciate any feedback as to why this may be?

  2. In response to Brian’s query, it first should be noted that there are currently no organisations UKAS accredited to test to BS 8612, so the question is a slightly academic one.

    Second, and however, it’s a long-standing principle of BSI public policy that it’s generally not acceptable for a British Standard to insist that a legitimate claim of compliance is dependent on third-party conformity assessment; and that is why BS 8612 and most other British Standards follow this rule.

    Most larger manufacturers who have their own test facilities will consequently choose to self-certify that they meet the requirements of BS 8612 because it is less expensive and avoids potentially costly fees to a third party to duplicate and assess tests already done in-house.

    BS 8612 requires that manufacturers provide technical data and other information to customers regarding design resistances of ridge/hip and verge products, as well as profile class of ridge-roll products. It is strongly recommended that customers ask for this information, as it is a good check whether a manufacturer has conducted these in-house tests.

    If manufacturers are not forthcoming with this data, that is a potential warning sign of false claims of compliance.

    In the event, customers always have recourse to refer allegations to their local trading standards authority if they think a manufacturer is making a false claim of compliance to BS 8612 or any other standard.


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