Construction Cabling Questions: Do You Need to Use Thermal Backfill?
Laying cables on your construction project doesn't just involve digging trenches, putting the cables down and then filling the trenches in again. The materials you use for the fill are also important. In some cases, you may need to use a specialist thermal backfill rather than a standard material. Why are thermal backfills used on some cabling jobs and do you need to use it on yours?
When Are Thermal Backfills Used?
Underground cabling may be kept out of sight and out of harm's way, but the soil on your site can affect the cables you lay. The cables can, in turn, affect the soil.
Different soils have varying degrees of thermal conductivity — some conduct heat more than others. If you're laying cables that get warm, such as power or data lines, then this heat dissipates out from the cables into the surrounding soil.
If the soil gets too hot and doesn't carry its heat away from the cables, then the cables may not work to optimum efficiency. They may give slower supplies than they should. Sometimes, they are completely compromised and break down. Plus, a soil that isn't a great heat conductor may dry out itself and become unstable. This could compromise your build in the future.
Thermal backfills solve this problem. They are used to surround cables when local soils aren't up to the job. That is because a backfill protects both the cable and the soil. It draws heat away from the cable but keeps heat out of the soil so it can't dry out. These backfills can be made from mixes of materials like cement, sand and gravel; some come in a liquid form.
How Do You Know When to Use Thermal Backfills?
If you aren't sure how the soil on your site will cope with cables, then you need to have it tested. A soil thermal resistivity analysis takes a sample of the soil and puts it through various tests. These usually assess the soil's thermal properties by exposing it to heat or moisture to measure its resistance.
If the test results show that the soil isn't going to work well around the cabling, then you need to consider using a different backfill that has better thermal resistance. To find out more about your soil's suitability, contact thermal conductivity soil testing companies. They can also help you choose a good thermal backfill if you do need to use one.