You want to complete your deck by giving it some finishing touches to make it perfect. There are a few ways to do this, such as using: L-corner trims, fascia boards or bullnose boards. All of the above will hide any rough edges on your decking, providing a smooth, seamless finish to your deck.
For you to obtain the best-looking decking possible, you must strategize. This involves planning where your deck will be, planning out the area, planning the design and planning how you will finish your deck. Doing these things will prevent any mistakes from being made, ensuring you have a beautiful-looking deck after you have completed your project.
L corner trim
An L-corner trim fits over the edges of your deck. Its name is derived from its shape, which is the same as the letter L. Edges of a deck that meets walls and fencing are often not covered by L corner trims.
This is because L corner trims are used to provide a smooth finish and an overall better aesthetic. So, in this case, using a trim would be futile as nobody can see it. Homeowners often use L corner trims to cover the edge of their deck because the end of a board does not match the aesthetic of the top of a board. Trims are most commonly fitted with adhesive; a recommended adhesive is Sumogrip.


Bullnose boards
Bullnose boards have a rounded edge along one side; this side will be what you can see when standing away from the deck. Most bullnose boards must be installed first, before the rest of the boards, due to the bullnose board requiring a clip under itself to be installed. Therefore, bullnose boards cannot be a last-minute thought.

Picture Frame Method for Finishing Composite Decking
Lots of homeowners like to design their composite decking so that it looks like a picture frame around the outside of their deck. This is a great finish to a deck, and picking two boards that have complimenting colours will create a great aesthetic.
You can achieve this aesthetic when you arrange the outer frames of your joists so that they meet each other. Now, place the different coloured boards around the perimeter of your joists to create the picture frame. With this edge finish, you will not see the inside of the composite deck board at any point.
Where the boards meet in corners, the boards can be mitred to create a seamless corner. Mitring is cutting the end of two board meetings in the corner at a 45-degree angle. Picture framing can be achieved with standard composite decking and composite bullnose boards.
Conclusion
You can finish the edges of your composite decking using the picture frame method. Also, you can use fascia or paint the edges to conceal the rough marks.