Key rules for deck installation

The following list covers some of the key installation rules of the UPM ProFi decking system, and is not a replacement for the full installation instructions.


The deck must be built on a well prepared, self-draining surface. Ventilation of the sub structure and the deck surface must be provided to prevent surface mould growth.

UPM ProFi Support Rail or UPM ProFi Alu Support Rail Small must only be installed on flat, permanently load bearing surfaces and fixed to the ground. If this is not possible, the subconstruction must be made from support rails or timber joists (hardwood durability class 1) which are connected to form a stiffened, single floating frame.

Raised decks should be constructed with UPM ProFi Alu Support Rail Large which may be clicked into UPM ProFi Foot, and must be inter-connected to form a stiffened, rigid frame.


Deck surface

Equalise the deck boards temperature before cutting and installation. Make a rectangular cut to even each board end.

Based on the temperature during installation, ensure the correct expansion gaps at the ends of deck boards. The following table is based on installing 4m lengths of decking in Europe, and assumes the deck boards temperature has been equalised.

Attach the boards to the UPM ProFi Support Rails with either UPM ProFi T-Clips or UPM ProFi Alu Rail. To ensure that the deck boards remain aligned, always fix one screw directly through the bottom tongue at the middle of each decking board.


If using UPM ProFi Alu Rail, cut the Alu Rail shorter than the deck boards it is joining together, (eg. 3mm shorter on each side for a 4 metre length) to ensure that the Alu Rail does not protrude from the end of the deck boards during colder months. When additionally using UPM ProFi End Caps with UPM ProFi Deck 150, the Alu Rail always must be cut 10mm shorter.

When two deck boards are placed end to end, two support rails need to be used where they meet. Separate Clips must be fixed to each support rail.

Decks made with UPM ProFi Deck 150 can be finished with UPM ProFi Rail Step, UPM ProFi Cover Strip or UPM ProFi End Cap. UPM ProFi Lifecycle and Vision boards can be cut and profiled to finish a deck. UPM ProFi (Piazza) Cover Strip can be used to finish a deck built with UPM ProFi Piazza and Terra 127.


Clean any spills and dirt as soon as possible. Clean deck regularly with water (and mild detergent). Always follow the cleaning, maintenance and use instructions from the downloads section.