Hi @Anita20,
Welcome to the Bunnings Workshop community, it is fantastic to have you with us.
When you say secure it properly, do you mean you would like to block it so no one can walk down this gap?
If so, could you please take some photos showing the location where the block wall ends? This would be the logical place to put something to block off the opening.
If one of the posts on your Colorbond fence line up with this location, that would be ideal, as the best option is to construct a very small return fence that attaches to the block wall and a fence post.
If you are looking to match the Colorbond exactly, you could use Colorbond components, such as posts, fencing rails and fence sheets to cover the gap. You would, however, need to cut them to size.
Alternatively, you could use timber fencing materials in the same way with posts, rails and palings.
Or, you could look at using a premade timber panel like this SpecRite Merbau Alternating Slat Fence Panel, although it may need to be cut down.
To get a plan together, we will need to know the width of the opening, what surfaces there are that materials can be mounted to and a basic idea of the look you are going for. If you can provide details on these things, as well as some photos of where you would like the barricade to be, we can certainly assist further.
Let me know what you think.
Jacob
