Some deficiencies do not pose a threat to public safety, but affect building components. On the other hand, certain deficiencies can directly threaten the safety of those who frequent the building - with a degraded facade - or walk around it. Take the case where window shelves are cracked and detached from the envelope or bricks that are detached from the structure (bulging), this represents a risk that loose bricks collapse on passersby.
Under the 122 Law, the building expert scrutinizes the building's facades and looks for visible deficiencies and symptoms that may indicate the presence of deficiencies hidden behind the exterior cladding. The specialist practices exploratory holes to check the inner layers of the envelope behind the outer screen. It warns the owner or the Co-ownership Union of the need to begin maintenance or replacement of deteriorated components based on findings and observations made on site.
Subsequently, the engineer writes a report identifying the deficiencies noted in relation to the facades and proposes appropriate solutions according to the severity of the deficiencies and the priority of the repairs to be made. Here are some examples of deficiencies and symptoms that can be found on brick facades:
The efflorescence on the bricks
The expert can observe efflorescence on the surface of the facing (white spots). These stains are, in fact, deposits of mineral salts that are driven by the migration of water from the inside of the building envelope to the outer surface. The notable presence of these white spots indicates that there is a sealing problem of the outer casing and that the materials are wet.
The absence of seals:
Often, the joints at the junction of the various components of the building envelope are missing in some places, such as at the junctions between the balcony slabs and the exterior cladding, around the devices that pierce the outer envelope. In this way, the water can infiltrate the structure through these junctions.
Corrosion on steel lintels and angles:
Normally, the lintels under the openings have free seats (lintels free). The lintel's role is to support the bricks above the openings.
However, the angles (structural lintels) are steel elements that are anchored against the concrete slabs, on each floor, to support the bricks in buildings that have a height of more than 11 m.
When the angles and lintels of steel begin to corrode, the rust of these steel elements causes a phenomenon of swelling of the steel. The latter causes the deformation of the lintels and the presence of cracks in the masonry adjacent to the lintels. In addition, the mortar joints experience a force that pushes these joints outward. This is the reason why mortar joints are seen coming off the masonry, where there are corroded lintels. The detachment of the mortar joints is a sign that the steel lintels are very corroded.
Crowded or absent hymenpleures
The weep holes are the water drain holes located at the base of the masonry facing and above the openings and at structural steel angles. The chantepleures are important elements to drain and ventilate the air space separating the masonry from the building frame.
Sealing joints around the openings:
These joints must always be in good condition to prevent water infiltration into the structure that causes premature deterioration of the building components.
Shears in the bricks
Corrosion of the steel lintels affects the capacity and structural integrity of the steel lintels. This weakness causes, over time, a collapse of the masonry, then the presence of shears in the bricks.
The absence of vertical and horizontal expansion joints
The exterior cladding can undergo several types of vertical and horizontal movement. If the impact of these movements is not taken into account with the creation of vertical and horizontal expansion joints, then cracks and shear result from these movements.