How to Level Concrete in a Trench
To level concrete in a trench effectively, a common technique is to use guide pegs set to the exact finished height, providing a clear reference point across the entire length. This method helps ensure the concrete surface is flat and at the desired elevation.
Establishing guide pegs before or during the pouring process is a fundamental step in achieving a level concrete surface within a trench. These pegs act as markers that indicate the target height for the wet concrete.
Steps for Using Guide Pegs
Based on standard practice, here's how to set up these crucial guides:
- Set the First Peg: Begin at one end of the trench. Hammer in a peg (typically a wooden or metal stake) until its top is precisely level with the finished concrete height. This first peg establishes the benchmark elevation.
- Use a Spirit Level: To transfer this height accurately along the trench, use a spirit level. Place the spirit level on top of the first peg (or on a straight edge resting on it) and extend it horizontally towards the next peg location.
- Set Subsequent Pegs: While keeping the spirit level perfectly horizontal (the bubble centered), set further pegs along the trench. Drive each new peg into the ground until its top is at the exact same height indicated by the spirit level resting on the previous peg or a straight edge.
- Spacing: Place these guide pegs at regular intervals, typically about one metre apart along the rest of the trench. This spacing provides frequent reference points for leveling the concrete.
- Verify Level: Double-check with the spirit level to ensure all pegs are at the same elevation relative to each other.
How Guide Pegs Aid Leveling
Once the concrete is poured into the trench, these pegs serve as visual and often physical guides. Workers can then use a straight board (known as a screed board) resting on the tops of the pegs (or the trench edges if they are suitable guides) to strike off or scrape away excess concrete, leaving the surface level with the top of the pegs.
Using guide pegs simplifies the leveling process, allowing for greater accuracy over the entire length of the trench compared to relying solely on visual estimation.
| Tool | Purpose |
|---|---|
| Pegs | Mark the finished height |
| Hammer | Drive pegs into the ground |
| Spirit Level | Ensure pegs are level |
