2.1 As all UPM ProFi deck products have a very low rate of moisture absorption, they can be installed horizontally with no incline. However, installing the boards at a gradient (e.g. 1–1.5 %) results in faster deck drying and the run-off rainwater will help to wash away dust.
2.2 As with all decks, UPM ProFi decks must be well ventilated and installed on a sub-structure that enables a free flow of air under the deck and good drainage of rainwater. Please note local building regulations and generally accepted practices concerning for example, the minimum distance of the decking to the wall of the building, and the possible need for drainage channels between a house wall and the decking edge.
2.3 When using UPM ProFi Alu Rail and/or Rubber Strip, it is mandatory to create additional ventilation in the deck to ensure a free flow of air underneath the deck. For example, if the deck is installed alongside a wall, ventilation grills must be installed along the whole length of the wall before the first row of deck boards. If the edges of the deck which are not adjacent to a wall are closed, then sufficient ventilation grills must be added along the deck edge to enable the free flow of air under the deck. Failure to do so may result in distortion and weakening of the decking over time.