WHAT NOT TO DO

when installing a composite wall cladding

Working with wood plastic composites (WPCs), especially the solid type like eco-Profil, is as easy as working with softwood timber.

One should never assume that the general rules for working with natural materials do not apply for wood plastic composites.

The main topics that have given rise to subsequent problems (and this holds for ALL WPC boards) are:

• foresee end-to-end gaps that allow for thermal expansion;
• design and build your cladding in such a way that sufficient ventilation/aeration allows the space behind the cladding sheets to dry out as thoroughly as the visible surface:
• always stick to the support beam or joist spacing that is prescribed by the vendor.

END-TO-END GAPS

WPC products tend to show some longitudinal expansion when heated.  On sunny days, the sun can easily heat a wall surface to over 60°C. To compensate for the effects of thermal contraction and expansion, the following installation standards should be maintained:

 Gap to be kept between the first board and an obstacle  (e.g. a window): keep 1 cm.

VENTILATE

Just as with natural wood, a long term difference in humidity between the front and the back of the board can eventually lead to distortion of the board.

Therefore, the following needs to be foreseen:

• sufficient space behind the supporting surface and the deck bottom, so as not to obstruct the natural flow of air below the deck;
• the top and bottom sides of the cladding need to be free to allow the natural air flow to aerate the space behind the boards and fully dry out the supporting beams. If needed, insects and the likes may be kept out of the cavity by obstructing the aeration vents with a mosquito net.

JOIST SPACING:

Supports clearance:

Max. 40 cm (16”) centre distance

When the sheets are to be mounted diagonally, reduce the on-center joist spacing by 10 cm (4”).