Some deficiencies in a building's facades do not pose a threat to public safety, but affect the building's components. However, some deficiencies can directly threaten the safety of those who frequent the building or walk near it. Consider the case where window sills are cracked and detached from the envelope or bricks are detached from the structure (bulging), which therefore poses a risk of the detached bricks collapsing onto passersby.
Under Law 122 , the building engineer inspects the building's facades, looking for visible deficiencies and symptoms that could indicate hidden problems behind the exterior cladding. The specialist drills exploratory holes to examine the internal layers of the building envelope located behind the exterior layer. Based on the findings and observations made on site, the engineer then notifies the owner or the condominium association of the need to begin maintenance work or replace deteriorated components.
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 carried out.
Here are some examples of deficiencies and symptoms that can be found on brick facades :
- 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 which are driven by the migration of water from the interior of the building envelope to the exterior surface. The noticeable presence of these white spots indicates that there is a problem with the sealing of the outer casing and that the materials are damp.
- The absence of sealing joints: often, the sealing joints applied at the junction of the various elements of the building envelope are absent, in certain places, such as at the junctions between the slabs of the balconies and the exterior cladding, around the devices that pierce the exterior envelope. In this way, water can seep into the structure through these junctions.
- Corrosion on steel lintels and angles: normally, the lintels under the openings have free courses (free lintels). The role of the lintel 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, in order to support the bricks in buildings that are more than 11 m high. When the steel angles and lintels begin to corrode, the rusting of these steel elements causes a phenomenon of steel swelling. The latter causes the deformation of the lintels and the presence of cracks in the masonry adjacent to the lintels. In addition, mortar joints experience a force that pushes these joints outward. This is the reason why we observe that the mortar joints are detached from the masonry, where there are corroded lintels. The detachment of the mortar joints is an indication that the steel lintels are badly corroded.
- Blocked or absent weep holes : The weep holes are the water drainage holes located at the base of the masonry facing and above the openings as well as at the level of the structural steel angles. Weepholes are important elements for draining and ventilating the air space separating the masonry from the building frame.
- Sealing joints around openings (doors and windows): these seals must always be in good condition to prevent water infiltration into the structure, which causes premature deterioration of building components.
- Shears in the bricks : Corrosion of steel lintels affects the capacity and structural integrity of steel lintels. This weakness causes, over time, a subsidence of the masonry, then the presence of shears in the bricks.
- The absence of vertical and horizontal expansion joints : the exterior facing can undergo several types of vertical and horizontal movement. If the impact of these movements is not taken into consideration with the creation of vertical and horizontal expansion joints, then cracking and shearing results from these movements.
Inspection of facades by a building engineer