Where possible, core drilling limestone blocks is the preferred choice of most reputable fencing contractors.
Core drilling for a Colorbond fence installation is generally considered the most aesthetically pleasing finish. When installed to a neat, level limestone block wall, the fence rails will sit flat on the surface exposing little to no gaps. The clean lines of the fence will compliment the wall and the wall will in turn compliment the fence.
Many people are not aware of how easy it is to install a fence with this type of installation method, although, as is the case with any building work, the correct equipment and knowledge is key to a successful fence installation.
Unlike installing with a post and panel type retaining system, the limestone block retaining wall can be installed to align the centre of the block with the centre of the surveyed boundary. When using a 1mtr x 350mm x350mm limestone block as a base for your fence installation, you can run the boundary with a 175mm centre (when installing a common fence), meaning the block will hug the boundary and will be exposed on just under approximately the 175mm boundary line taking into consideration the bottom rail dimensions. When installing on a Limestone block it is advised that the fence be installed in the centre of the block. This will not only look pleasing to the eye but will more importantly provide the fence base with the best structural support.
The procedure is displayed and described in order of the pictures you see here from a recent Perth Trade Centre fence installation.
On this particular installation we were working with an existing natural limestone wall and screening an unsightly pre-installed picket fence that was installed on the outside facing wall.
The top of the wall is aligned, marked and core drilled using a core drill machine. It is very important to make sure the measurements are absolutely perfect. This is considered the most important part of the job.
The core is then removed leaving a hole that will accommodate the base of the fence post.
The bottom rail must be in line with the hole and boundary dimensions, also taking into consideration the size of the post.
The post is then lowered into the hole attaching to the rail joining from one panel to the next.
The hole is filled with the correct structural mix ratio of cement and aggregate as per post fixing standard.
Allow adequate time for the cement aggregate mix to cure before completing the fence installation.