Counterbattens sealing substance is used for sealing nail penetration through the roof underlay.
At first the roof underlay is applied over the rafters and fixed with non-corrosive flat headed nails or staples. After that the sealing substance is applied as one bead onto the middle of the counterbatten. Counterbatten is applied onto the underlay within the film formation time and fixed to the rafter with nails or screws.