When and how it is possible to create “openings” in existing or bearing walls

There creation of new openings for new windows or new access to other environments in existing walls, especially if bearing wallsit is not always possible even if functional to the renovation objectives as it needs in -depth structural analysis. There Refunctionalization of spaces In the context of existing buildings, it is a recurring design operation today, as it outlines the needs of new users who buy or restructure properties, with ideas of management of spaces now different from those of 20-30 years ago.

But is it always possible to make an opening in an existing wall? The answer is no! The realization of an opening requires one Technical study on its feasibilitymainly respecting Resistance and rigidity requirements that the wall needs to maintain, but also of the respect of the architectural decoration and/or any condominium regulations: to create a new opening independently could identify the birth of a building abuse, as well as cause important structural problems which – if underestimated – they could compromise the static of the building and be the cause of collapses, partial or global, in the building body.

The first distinction that is necessary to do concern the type of wall on which we are going to create this new opening:

• If it is a wall carrieror a wall that has one structural function within the building bodythen the problem requires a study ad hoc of a professional, who will have to deal with the project of the interventions necessary for the realization of these openings. The interventions can be of various types and this mainly depends on the structural problems that this opening generates.
• Instead, when we are dealing with walls non -supportingthe problem is simplified. In this case, the realization of the opening does not require any type of structural interventiontherefore a dedicated project is not necessary. However, it will be necessary to understand whether the opening can be achieved from an architectural/constructive point of view. In some cases, for example in condominiumsit is not always possible to create new openings, because they would be the cause of variation of the original prospects of the building. These requirements, of course, must be considered even in the previous case, although they usually become less binding than the structural problems.

Therefore if in the case of openings in walls supporting the Project drawn up It is the Guide for the construction of the opening of the openingin the case of non -load -bearing walls, a guide is needed to avoid problems during processing. For this reason it is appropriate that the processes are carried out by expert hands: the disorder caused to partition (internal dividing wall) or al tompagno (perimeter wall) It could still cause minimal slopes of the brick, the construction material. In general, however, the support of the loads in the wall of the wall above the hole is necessary, and this is why the so -called is inserted architrave at the end of the top part of the opening. Alternative also often used is the construction of a flat.

Structural problems

The realization of new openings, however, can bring with it various structural problems. Let’s see the main ones.

Static loads

The problem related to the creation of a new opening in a supporting wall is linked to Disorder caused to the flow of forces internal to the masonry which was created to spread the loads from their point of application to the foundations. In the opening of a new hole, whether it is a door or a simple window, all the loads aligned with the opening vertical they must find a new way to migrate to the foundations. Thus a new path of forces is created that is supported by the existing masonry (which could however request a reinforcement), but irreparably causes a weakening of the central masonry area with respect to the hole, which now becomes only a weight and is no longer able to redistribute loads above. Also in this case, therefore, it is necessary to insert an architrave that eliminates this weakness. Unlike what has been seen before, however, both the greatest weight of the supporting wall compared to an non -supporting one, and any additional loads that weigh on the wall itself, require the creation of a more robust and demanding architrave than those that are usually seen on the openings of non -bearing walls. This restarts, at the same time, an indirect structural function to the part of the wall that weighs on the architrave, which now acts as a support and element of distribution of loads in the lateral masonry areas to the opening.

The role of seismic actions

Having structural function, the supporting masonry also represents source of resistance for horizontal actionsfor example seismic, of the entire structural body. Therefore, it is necessary to understand in this case also how much impact this new opening has impact on structural response to horizontal forces of the entire wall.

As a result of the opening, the entire wall can losing a significant part of resistance or stiffness to the horizontal forces, thus compromising the seismic response of the entire building. To remedy this problem, it is necessary to make one circlethat is, a real crowning of the opening through a sufficiently rigid and resistant structure to be replacement for the role that the masonry that was removed before. The circle can be designed and built both with steel elements and with a reinforced concrete structure. The size of these elements are subject to a dedicated structural project and therefore require the intervention of a competent technician on the subject.

In any case, the openings in the load -bearing walls must provide, in the construction phase, appropriate areas of temporary punishment of the floorsto ensure safety during the processing processing phase and inserting new structural elements.