Phil Ball of Alpha Rail, provides advice on how to survey site condition before measuring up for metalwork.
When a project is specified to include metal railings, gates or guardrail, ensuring that they will fit first time is essential. This stops delays in other aspects work and will usually involve a visit to the site to carry out a survey to take measurements. This helps assess the length of the railings required for each section, as well as the ground levels and any curvatures. This will help us to determine if any raked or radius panels will be required.
These projects normally fall into three main categories: Highways, Housing and Parks.
On highway projects it is important that the kerb lines are complete. This includes all drop kerbs for crossing over points and central pedestrian refuges. If metal railings or pedestrian guardrails are part of the design on the splitter islands, these need to be in place too. A splitter island is a raised or painted traffic island that separates traffic in opposing directions of travel.
On highway projects, pedestrian guardrail and pedestrian parapets are put in place to guide pedestrians to safe crossing points.
On new housing developments the ground works need to reach a point where the boundaries and pathways along which metal railings will feature are clearly defined.
If metal railings are necessary to follow pedestrian pathways, this usually means that the pin kerbs must also be in place. If metal railings are necessary for property boundaries, this requires ground leveling in their final state. This is so that any gradients and curves can be part of the calculations.
Public Parks and Gardens
For parks and gardens, the conditions explained above are similar, in that the boundaries and path edgings need to be in place.
However, also on a park or garden project, metal railings and trip railings may well be used. These deter visitors from trampling on gardens or to demarcate different areas within the park. This means that metal fencing, such as estate railing, may run across open land.
In these instances, the lines where metal railings run need to be clearly marked out. Usually this is achieved by inserting timber pegs at regular intervals. Any regrading of the ground needs to have been completed. Regrading is the process of grading for raising and/or lowering the levels of land. Regrading is typically performed to make land more level (flat), in which case it is sometimes called levelling.
In essence, to conduct a thorough survey in one single visit and ensure measurements are precise, the surveyor needs to be able to determine the final fence lines and ground levels.