Answer: The manual for the horizontal probe provides some instructions for installing horizontal casing in soil. Most of these instructions will apply to your application as well. For example,
- The traversing probe requires 70 or 85 mm (2.75 or 3.34") casing.
- One set of grooves must be vertical. This is essential. Check for this during installation.
- Telescoping sections are not recommended or needed.
- Casing should be flat and straight. It's ok to build in an inclination for drainage.
- A pull cable is required to pull the probe to the far end. Install the cable as you assemble the casing.
For your application, also consider this:
- Support the casing well, at least every 5 feet and under couplings. Tie the casing to the supports so that it does not float upwards when the concrete is poured. Wrap the joints with tape to make sure grout does not enter.
- Remember that the casing is plastic and weaker than steel. Avoid pouring concrete directly onto the casing.
- The casing is plastic and will start deforming if temperatures exceed 82° C ( 190° F). If the ambient temperature is above 26° C (80° F), you may need to fill the casing with cool water at the same time as you are pouring concrete. Make sure that the casing is supported by the concrete before filling it. There are other ways to avoid high temperatures as well, such as icing the concrete.