When modernizing heating in a cottage, first determine which duct you want to insulate. The warm air distribution duct, ventilation, and flue pipe have different requirements. A similar appearance of metal pipes is not a basis for using the same mat and fastening method.
Draw the route and mark problematic spots
In the sketch, include the heat source, branches, passages through partitions, and duct terminations. Add information about the surroundings: wood, existing insulation, construction, and access to connections. In a periodically used house, it is also worth recording signs of moisture and the condition of materials after a longer period of inactivity.
The choice of insulation should result from the temperature and the requirements of the complete air distribution system. Do not assume that every duct near the fireplace requires ceramic insulation just because it withstands very high temperatures.
Blanket and board serve different purposes
Vitcas ceramic fibre blanket is a high-temperature material for the applications described by the manufacturer. Its use requires proper fastening, protection, and consideration of the safety data sheet. Do not leave loose fibres in the airflow directed to the rooms.
HT fireboard may belong to a specific finishing system, but it does not automatically replace duct insulation or a designed passage through a wooden wall. For both formats, a specific function in the construction must be determined.
Maintain access and airflow
Do not hide connections that require inspection under a layer that cannot later be removed. Insulation should retain its thickness and the fastening method provided in the system. Accidental squeezing of the material with straps is not a universal installation method.
If the problem is uneven heating of rooms, also check with the contractor the route of the ducts, their cross-sections, and settings. Additional insulation alone will not fix every air distribution error. If a flue leak is suspected, a separate assessment of the flue system is required before further use.