How to correct thermal bridges? The three strategies to follow


Emma Potter

Correction of thermal bridges and the use of thermal insulation

Thermal bridges are always corrected withuse of thermal insulation elements. The insulation must guarantee thermal protection to the building without interruptions. Each interruption corresponds to a thermal bridge not resolved.

The now large-scale introduction of thermal coat has made this concept of wrapping the building with a more familiar and habitual continuous thermal protection. The thermal coat plays the role of most important and significant intervention for the energy transition, because in addition to improving the energy efficiency of buildings it guarantees a high living comfort as it intervenes on the most significant parameters: condensation, mold and radiant temperature.

Given that “The world is beautiful because it is varied” it's not always possible spread this blanket or it is not possible don't interrupt her. And then it becomes necessary to intervene with design creativity, the result of cultural and technical preparation, experience and passion, which can help to reach the solution. Below we will see, in particular, a strategy that can be usefully applied even in these cases.

The problems caused by thermal bridges

Thermal bridges exist and must be corrected. If a pillar in the masonry causes the formation of a thermal bridge, the pillar should not be eliminated but rather weakened or even canceled the negative problems connected to it. And this is the primary role of quality, careful and detailed planning.

The problems to be addressed are:

  • L'increase of energy dispersion;
  • there decrease internal surface temperatures;

both must guide us in resolution of the thermal bridge.

Thermal bridge correction: the three strategies to follow

Strategy 1: Insulate from the outside
This is the most classic case: the concrete pillar inserted into the double-headed solid masonryconstruction type widespread which is very easy to come across.
The most advantageous correction method involvesapplication of the external thermal coatan intervention that is now common thanks, also, to the tax incentives provided for its installation.

Coating insulation must always be considered as the main and decisive intervention for all thermal bridges due to the insertion of a different material in the wall (pillars, beams, curbs, architraves…).

Strategy 2: give continuity to the external insulation, without interruptions
Let's address this topic using a always problematic knot (both in the design from scratch and in the renovation of existing buildings): the insertion of the cantilevered floor onto the external wall. It is the theme of thermal bridges caused by terraces and overhangs.

In such cases the thermal insulation that wraps the building like a blanket it must not have interruptions; this strategy consists precisely in following all the geometric “movements” present in the building.

Strategy 3: “the stocking”
It is not always possible to create external thermal insulation, either for the intrinsic characteristics of the facadeyou want for one of his historical-testimonial bondyou want for the reluctance of the other condominium owners. Since isolation is, now more than ever, necessary, in such cases it is necessary isolate from the inside, which presents various operational and thermo-hygrometric difficulties. What these situations have in common is the impossibility of insulating from the outside and having to interrupt the internal insulation due to an element inserted into the wall which therefore determines the formation of a thermal bridge. Real cases can be the internal wall that fits into the external wallthe attic that is inserted into the external wall or the internal wall that rests on the attic or placed under a roof insulated from the inside).

This strategy indicated as then comes to our aid “thermal sock” which involves covering the orthogonal internal wall with a sock for a certain depth (determined during the calculation verification phase at the EF), until the temperature of the wall reaches, from that point onwards, the desired temperature. In essence, the sock insulates the wall by distancing the point where heat loss from the outside occurs.