While you can use glue to hold composite decking boards in place, we do not recommend using glue as the primary fastener. You can use glue as the secondary fastener to join the fascia to your composite decking edges. Before you use glue, please consult your user guide so that you will know more. Or, you can read this write-up further.
How to Join Composite Decking Boards
Joining composite decking boards is easy, and you can join them together with clips and fasteners or with screws. The technique you choose depends on the types of composite decking you are installing. We will come back to this later. Aside from clips and screws, you can use glue to reinforce your composite decking and to make it tight.
Using Clips and Fasteners
Clips and fastener go with grooved composite decking. The process of installing your composite decking starts with clearing the area. You should remove dirt and grass from the site and use chemicals to ensure that grass won’t grow on it again. After you have measured and cleared the spot, you can dig the holes that you will put the post.
The holes should be deep enough to hold the posts in place. Then, you should mix cement and pour the mixture inside the holes. After the mixture has solidified, you can start attaching the outer frames to the post. At this stage, you should use screws to clamp the frames and the posts together. Note the use of screws and not glue. After joining the other structures, you can start attaching the inner framing or joist.
Note that you will attach the joists to the frames you clamped to the posts. Make sure that the space between the joists should not be more than 16 inches. This requirement is for a residential setting. If you are installing your composite decking in a commercial environment, space should not be more than 12 inches.
You will accomplish this task with the aid of screws. If you want to, but it is not necessary, you can put glue in between the joists and the frame. After that, you can start arranging the composite decking boards on the joists or substructure.
Start from the side of a wall by fixing the starter clip. Hold the starter clips down to the joist with fasteners. Then, push the composite decking boards into the starter clips so that they will hold them down. Note that you will not screw the boards down directly to the joist. Instead, it is the clips that you fix to the joist. This method of installing composite decking applies to grooved decking boards only.
For the ungrooved decking boards, you screw them down directly to the joists. So, instead of using clips and fasteners, you will use only screws. When you have finished installing the first sets of boards, you can start installing the remaining. If you are using grooved boards, you will need intermediate clips. If you are using ungrooved panels, you will use screws. You should make sure that you space the boards 5 mm apart.
This spacing is crucial because of expansion and contraction. If you don’t leave a space between the decking boards, they will buckle. You can attach rails or the post that will support your pergola to your decking. If you want to build a step, you should make the step at this stage. When you have finished installing all the composite decking boards, the next thing to do is to cover the edges.
Covering the Edges of Your Composite Decking

You can cover the edges of your composite decking with fascia boards. This option will result in visible screws in your composite decking skirting This process is simple and requires that you use the right fascia boards for the task. You should attach the fascia directly to the frame or substructure with screws. It should be after you have pre-drill holes in the fascia boards. You should screw your fascia boards in place.
We do not recommend using glue as the primary fasteners. After you have used screws, you can then add glue to the spot so that it will be firm. This process is optional and does not make your fascia better than one that does not use glue. Please make sure that you leave the right expansion gaps where the fascia board ends meet. You should leave a minimum of 0.2% of the board length for expansion.
Conclusion
We do not recommend that you use glue as the primary fastener when installing composite decking boards. You should use either clips or screws to install your composite decking boards.