Ceiling collapse is the technical definition of what happens when the ceiling collapses. Ceiling collapse, however, is too general a term because it does not explain exactly what happened. Of a ceiling, or ceiling, the plaster or even just the paint might give way.
In contrast, displacement is a deeper damage because it involves the detachment of the brick foundation for buildings constructed of reinforced concrete.
In these structures, the slab is made up of the piñatas, brick blocks that fill the gap between the steel joists that makes up the brick structure. If, for any reason, the steel mesh no longer fills the spaces between the joists and suffers corrosion effects, swelling will occur, causing the bottom to fail.
Floor slab caving: causes and interventions
This is damage that does not jeopardize the structural integrity, however, it is a serious risk to the safety of those who frequent those spaces, if one has the misfortune to be present during the detachment.
Before we get to that point, however, the attic will almost certainly have already shown signs of deterioration such as swelling and plaster failure. This is why it is important to intervene at the first signs to avoid having to later resort to more invasive interventions to repair greater damage.
You don’t need a specialist to notice that a ceiling is showing cracks and bulges.
One of the main causes of this phenomenon is called carbonation, a chemical phenomenon that corrodes the steel core of concrete. This phenomenon, accompanied by the presence of chloride ions, can deeply degrade a brick structure to the point of causing it to detach. And this can happen even in buildings that are not too old, if not done properly.
When signs of this type become visible, it is necessary to take action as soon as possible to prevent breakthrough, which involves more extensive remedial work. In fact, in case of a breakthrough, it is necessary to first replace the steel structure and then fill the gaps with insulation material.
To prevent the same problem from occurring in the future, you can use Shove mortar, a special material on the market today intended for this purpose.
The consequences of floor slab debonding
Breaking through the floors will probably not cause the building structure to collapse, however, it is a major safety issue, directly affecting the safety of people residing in or attending such facilities. It has to be said that although crumbling is an indicator of deterioration, this does not necessarily compromise the load-bearing capacity of the building, but it does highlight an advanced stage of deterioration, particularly related to concrete carbonation. This chemical process, as mentioned above, results in corrosion of the metal reinforcement, increasing the risk of slab debonding.
However, this problem does not only affect old buildings or those in an obvious state of disrepair; even newly constructed structures can be subject to crumbling, making this risk a common concern for all types of buildings. Brick floors are used in both historic and modern buildings, and the age of the building is not a primary factor when it comes to vulnerability to concrete carbonation.
Teknoprogetti has been carrying out detailed analyses of the security status of buildings for many years, and is able to perform a thorough diagnostic report to plan the necessary interventions to ensure a higher level of security.
Recognize indicators of subsidence in floors
The slab failure is the result of the neglect of many signs that preceded it. Over a shorter or longer period of time, the attic usually shows moisture stains or presence of mold indicating the presence of water infiltration. Water is certainly one of the elements that most harm the tightness of concrete rebar.
A second phenomenon that can occur that shows signs of slab degradation is the presence of cracks or fissures that alter the ordinary appearance of the surface. From their depth, one can tell whether they are superficial damages that can be remedied by re-plastering or whether they are deeper cracks that deserve a more thorough investigation.
The same goes for the appearance of bubbles, bulges, or hollows in the plaster: you need to understand the extent of these and whether they show signs of moisture that indicate the presence of seepage. All of these occurrences, although small, can cause small detachments of material that could, however, be the precursor to more extensive subsidence.
Breaking through rarely occurs without any of the preceding events having occurred, but if episodes of concrete carbonation have become evident in the same building, it is worth doing more in-depth analysis to avert the hypothesis of corrosion of the structure without its effects showing yet.
How to repair a collapsed slab
Repairing the slab breakthrough involves the new installation of a load-bearing structure. It involves recreating a substrate on which to rest the slab, after filling the voids with insulation material. Of course, first the damaged parts are cleaned and the deteriorated material is removed. At this point, the damaged steel reinforcement is replaced to restore the load-bearing joists to full working order.
It is important to fill the spaces left empty by the breakthrough with polystyrene or expanded polystyrene, which not only restores the uniform surface of the attic but also provides excellent acoustic and thermal insulation.
In order to prevent the concrete reinforcement from corroding again, resulting in the breakthrough, it is recommended to install an anti-breakthrough mesh made of fiberglass. The existence of this material is proof that these are widespread phenomena in construction to which research continually offers new solutions and which guarantees against the risk of future failure.
Where feasible, a plasterboard ceiling may be considered to cover the imperfections caused by the breakthrough. With this method, the attic is effectively repaired and preventive measures are put in place to help improve the safety of the building.