The cold roof

The cold roof can certainly be described as the classic roof construction method. Despite numerous advantages, however, it is no longer the standard design method for rooftops today. Find out later all the advantages, disadvantages and alternatives to the cold roof.

The cold roof through the ages

The cold roof was for many decades and actually even centuries the typical execution of rooftops. This is partly due to the original use of the attic as storage. But with increasing population density and increasingly expensive housing, the attic attained greater importance as living space. Even more efficient energy saving options are increasingly being introduced.

The different roof structures

This also reduced the importance of the cold roof. Overall, you can differentiate between three basic roof types.

  • the cold roof
  • the warm roof
  • the inverted roof
  • the inverted roof in different variations

The cold roof: roof

The construction of the cold roof

The structure of the cold roof is relatively simple, but may vary depending on the individual construction in details such as additional film layers, etc. However, the basic structure is always as follows.

  • outer roofing, roofing (roof tile, roofing felt, etc.)
  • Ventilation
  • vapor barrier
  • internal insulation

In addition, there may still be a sealing layer between the roof skin and the ventilation layer. Especially with flat roofs, an important sealing layer can be found here. The ventilation layer is thus (depending on the roof structure) between the rafters and the battens for the roof skin.

Important for the cold roof construction

The vapor barrier must never be replaced by a vapor barrier, as this type of ventilation is the basic principle of cold roof ventilation. As a result, the insulation and the interior fittings (wallpaper, plasterboard, laminate, wood, etc.) must also be permeable, ie vapor-permeable.

Advantages and disadvantages of the cold roof

The advantages of the cold roof are thus obvious: there is an excellent ventilation under the roof. Thus, the temperature directly under the roof is extremely constant and regulated at a low level. In the summer it never gets overly hot in the rooms underneath, in winter the ventilation is very reliable.

The disadvantages

The disadvantages of the cold roof are actually to be found in the fact that the materials must be well matched to their position in the roof structure, so must be correspondingly vapor-permeable from the inside out. This makes the construction of a cold roof a little more expensive than that of a warm roof. The hot roof would probably have become standard earlier, but there are building materials that allow a reasonable and durable warm roof construction, only a few years.

Special features around the cold roof

Explicit flat roofs have long been designed as a warm roof, because the cold roof transverse ventilation of a flat roof turned out to be difficult. However, flat roofs between the 1950s and the 1990s are currently used for roof structures that are prone to leaks. This circumstance is due to the already mentioned fact that efficient building materials for the warm roof design have only been available on the market for a few years.

Tips & Tricks

Converting a cold roof to a warm roof is just as involved as reversing it. Because the insulation properties are completely opposite in the two roof shapes from the inside out. In addition, when changing to a heated roof, you must provide adequate ventilation in all rooms in the house.

Of course you will also find articles in the house journal about the other roof construction techniques, such as the warm roof.

Video Board: Cold flat roof construction Explained