How to Install outdoor WPC composite decking boards

WPC Decking, Composite Decking Installation Guide

How To Install WPC (Wood Plastic Composite) Decking

WPC Decking is composed of natural wood powder, plastic and additives in a certain proportion. WPC Decking is a 100% eco-friendly product with many advantages: waterproof, anti-corrosion, moisture-proof, anti-UV, anti-scratch, anti-pressure etc, so WPC decking has much longer service life than real wood decking. Learn more about wpc composite decking boards>>

WPC Outdoor Decking
WPC Composite Decking
Co-Extrusion Decking
3D Embossed Decking

About Space/Span Between Two Joists:

On general condition, the joist span would be no more than 35cm when fixing WPC decking floor, each board requires at least 3 joists. The joist span is decided by board thickness. For example, we should take the wall thickness, board thickness into consideration if fixing hollow decking floor , as it would be influence the joist span directly.


1.The joist span should be shorter under a special condition and the over-loading situation.

2.Stainless steel threading screw is the first option for installation; The screw length is adjusted with the board thickness. Normally, 20mm deepness for a screw fixed into the joist as a calculation for the screw length, don’t make the screw too tightly.

3.The clip and screw will be supplied with the decking floor to customers, it’s easy and better for installation when use our clip and screw for installation. The clip will make 2 boards keep space, don’t compress the clip to decrease the space.

WPC Decking installation guide

WPC Decking installation guide

WPC composite decking installation steps

1.Drill holes on the concrete ground, put the expansion screws into the holes without exposing, see as below image:

WPC Decking installation guide

2.The space between the joist interface and wall head is necessary, the joist should be put in crisscross to avoid the joist interfaces in the same line.

3.Use stainless steel screw to fix the joist, making sure the screw head should be lower than the joist surface, no obvious concavo-convex.

WPC Decking installation guide
WPC Decking installation guide
WPC Decking installation guide
WPC Decking installation guide

4. Use the screw to fix the first and the last wpc decking board, or, use the screw to fix from the side; or use edged board with clip to fix. Please choose according to your actual requirement.

WPC Decking installation guide
WPC Decking installation guide

5 Please drill the holes before fix the screw, the diameter of pre-drilling is no more than 3/4 of screw diameter.

6 After fixing the first board, please use the clip to install in turn.

WPC Decking installation guide
WPC Decking installation guide

7. Please use ruler to calculate the width of last board for space reservation in order to cutting properly.

8.Please put the boards cut in turn, push the clip from the last board and the second board from the last, the clip is putted well and please don’t fix directly.

9.Drilled and use the screw to fix the last board, pay attention to keep space between decking board and side board.

10. After fixing the last board, then use the screw to fix the clip prepared.

WPC Decking installation guide
WPC Decking installation guide

WPC Decking Installation Video

3. Space

3.1 Considering of draining, cleaning and slightly expanding-shrinkage, it’s necessary to keep space from the side to side, head to head.

3.1.1 From side to side, the space should be more than 6mm; Installing in cold winter, 10mm space is better.

3.1.2 From head to head, the space is decided by the board length, fixing temperature, expanding shrinkage data (ζ≈0.9×10-4) and the maximum temperature of local area.

The calculation method for space of head to head, as follows:

A board with length “L

The maximum temperature of local area is Tmax

Fixing temperature is T

Calculation method: △L=ζ×(Tmax – TL

  • For example: a board with 2meter long, fixing temperature is 10℃, maximum temperature is 40℃ of a year, the space for head to head should be: L=ζ×(TmaxTL=(0.9×10-4)×(40-10) ×2000=5.4 mm 

Note: WPC decking floor requires a suitable space when installing, and should be fixed with joist. Don’t fix WPC decking floor with any solid body, such as concrete, roof or terrace.