Which heating cable to choose.
There are a number of proposals for protecting the sewerage and water supply from frost in low-temperature conditions. One of the most accessible and simple is the use of a heating cable. 
How it works:
- Cable heating does not allow freezing of water or sewage;
- Performs the function of heat saving in the case of external heating transition from one building to another, which is an important aspect in energy saving;
- Allows you to keep a certain temperature in the system;
- Prevents condensation in the pipe and thus prolongs the service life of the thermal insulation;
- Allows to produce in a certain place the initial warming up and to ensure unimpeded passage of liquid of a certain temperature.
To date, the method of cable heating is used in several types of systems: 
- Self-regulating, which is equipped with special heat-sensitive matrices, which makes it possible to monitor the power of the heating wire, depending on the temperature change in the water pipe. The advantage of this system is that cable overheating is not allowed, and it also saves energy.
- Resistive, which is equipped with constant resistance heating cables. The commissioning of such a cable is only possible after accurate calculations and more careful monitoring of its operation. The disadvantages of such a system are a rapid deterioration, as well as the need to purchase additional devices that will regulate the operation of such a system.
Ways of mounting the heating system.
Which method to use in the heating system will depend on the location of the pipes, their kind. It is also taken into account whether this will be done on already laid pipes or new ones.
There are two ways of mounting:
- External;
- Internal.
Laying the heating cable over the pipe( outdoor method) is more convenient and simple. If your communications are made of plastic, then they must first be wrapped with adhesive tape and only then you must lay the cable. 
Internal installation is applied when the pipeline is already laid, it should be noted that for water pipes this kind of insulation is not suitable.
In any case, you need to choose a wire so that the heat that it will give out is an order of magnitude higher than the temperature in the pipeline. The cable is laid along the length of the pipe in parallel or spiral, it all depends on the required design capacity. The cable itself is covered with heat and waterproofing( it can be foam, glass wool or other materials).The layer of insulation has a thickness of not less than 10 mm.
After this, the wire must be secured with a special mounting tape. And the last layer is the wrapping of the structure with aluminum foil, which makes it possible to distribute heat evenly. 
When planning the system and purchasing materials, do not forget to also purchase the necessary mounting and fixing elements, such as valves, temperature sensors, switches and the like. Ask for help in specialized shops, whose consultants will prompt and help you choose the quality and details you need, and for installation it is better to use the services of professional plumbers-installers.
