Can I use Rockpanel boards for non-ventilated applications?

Rockpanel exterior cladding is used for many different applications, including facades and various roofline applications. Although we usually recommend to use Rockpanel as part of a ventilated facade, it is possible to use Rockpanel boards for non-ventilated applications under specific conditions.

Thanks to its unique characteristics and the vapour-open structure of Rockpanel Colours (without a ProtectPlus layer) this product can be used in specific situations in non-ventilated constructions. In situations where the preconditions can easily be fulfilled, for example such as infill panels and dormers, the absence of a cavity can allow for thicker insulation which leads to a lower U-value.

This makes Rockpanel Colours (without ProtectPlus) very suitable for specific renovation projects. This means that you can:

• create additional space for thicker, more effective insulation
• narrow the structure using the same thickness of insulation
• install without the need to remove or replace the existing structure under certain conditions

How can you use Rockpanel boards for non-ventilated applications? These are the preconditions for non-ventilated applications of Rockpanel Colours boards (without ProtectPlus). All of these requirements need to be met.

• It should be an interior climate with a maximum vapour pressure of 1320 Pa. This is the value for normal housing and office buildings, which means it’s not possible for swimming pools or factories)
• The sum of the S_d-values of the materials on the inside of the structure down to the insulation should add up to at least 10 m. This value can be achieved with a 0.15 mm thick PE-membrane as vapour barrier and drywall.
• The sum of the S_d-values of the materials on the outside of the structure down to the insulation should add up to less than 2.5 m.
• The inside of the structure should be airtight so that no warm air, containing moisture, can penetrate through the structure.
• The attachments of the boards to the structure should be watertight, so that rainwater or cleaning water can get behind the cladding. This means that horizontal joints between the Rockpanel boards are not allowed. Vertical joints can be applied, but should abut at a timber batten covered with a 3 mm x 60 mm soft adhesive EPDM foam gasket.
• If the entire construction is in the open, it is important that all connections are watertight.
• Can be applied on small surfaces and as infill panels.
• Only Rockpanel Colours without ProtectPlus can be used in a non-ventilated application. The S_d-value of Rockpanel Colours without ProtectPlus is 1.8 m.