Mineral materials, glass wool
Thermal insulation is produced by various materials, differing in their properties and methods of installation. Each business executive chooses the material in accordance with the needs and budget. So, what materials for the thermal insulation of pipes exist. 
This is the most affordable and budgetary option for thermal insulation. These materials have excellent insulating qualities, and also are not subject to burning and high temperatures. Glass wool, as well as mineral materials are often used in industrial enterprises and housing and communal services, because of the cheapness.
Heaters of this type have a lot of drawbacks:
- A laborious and uncomfortable installation. Mount it to the surface of the pipe it must be carefully.
- Thermal insulation properties, like mineral wool, and glass wool are lost when wet. Therefore, this type of insulation does not always help to keep the pipes from freezing, and on top usually they are also wrapped with waterproofing material.
- Low durability of glass wool. Therefore, the statement about the budgetary nature of the option seems very controversial.
- The material is not completely safe for workers installing it, and can cause allergies.
Foamed polyethylene - an excellent alternative to other heaters.
This material is used more for sealing polypropylene pipes. Produced in the form of a pipe-like hose or shell with a cut, which simplifies its attachment to the pipe. Installation of this insulation is easy, it will last for a long time without changing its technical characteristics. They produce shells for pipes of different diameters. 
The main disadvantage of foamed polyethylene is its high flammability. Therefore, it does not produce thermal insulation of pipes near electrical cables. To fix the shell use scotch tape. The latest novelty of the construction market is foamed polyethylene in cylinders, which can be sprayed like paint. Such a coating is well fixed on the surface of the pipe and does not require additional fixation.
Polyfoam, also styrofoam
Polyfoam is much more rigid than polyethylene, and due to its structure, it is absolutely not afraid of moisture and has low thermal conductivity. Polyfoam also has its drawbacks - it is combustible and is therefore considered to be fire hazardous. In addition, surprisingly, various rodents like to eat, and therefore can not be responsible for its longevity. 
Polyurethane foam - insulation with a mass of advantages
By appearance it is very similar to ordinary polystyrene, but the structure of the cells is different. Advantages of polyurethane foam are as follows:
- heat losses are reduced to zero;
- water resistance;
- low weight of material;
- service life reaches 50 years without loss of technical characteristics;
- rodents do not like it, nor does it reproduce mold or fungus.
Also available is polyurethane foam in cylinders, sprayed similarly to foamed polyethylene.
The disadvantage of this material is the phobia of ultraviolet radiation. Under the influence of sunlight it decomposes. Therefore, it must be painted on top. 
Alternative methods of pipe insulation are the pipe-in-pipe method, where the natural insulation is the air layer, as well as the thermal paint. However, thermo-color or otherwise liquid ceramics is quite expensive material, but promising.
As you can see, there are a lot of heat-insulating methods, and the choice is yours.
