Angers, October 15, 2016: shortly after midnight, a balcony of a recent residence in the city center collapsed, taking with it the 18 young people who were celebrating there.
Results: four people died and fourteen others injured.
The trial, still ongoing, revealed significant defects in the construction.
But this is unfortunately not an isolated case: commissioned following this tragedy, a report from the Construction Quality Agency (AQC) noted 41 falls from balconies between 2004 and 2019. There would have been, in reality , almost five times more, the majority having caused no casualties and, as such, having gone unnoticed.
Concrete balconies potentially more fragile
Recent or old building, wooden, metal, concrete or stone balcony: the risk of collapse spares no building and no constructive process, although with some nuances.
“
Recent buildings seem to be more affected than older ones because the accidents mainly involve concrete balconies, a material that has been developed since the 1950s. The AQC has estimated the average age of buildings at 33 years. faced with falling balconies
", explains Benjamin Lefébure, building engineer and co-founder of the company Les Secrets de l'Immo®, specialist in turnkey rental investment in old properties to be renovated.
“
The old stone balconies were generally covered with lead which guaranteed them excellent waterproofing;
concrete balconies are covered with waterproof paints or resins, which are much less effective than lead.
In the presence of infiltration, the steel which supports the concrete corrodes and weakens the structure
,” he adds.
Read also Instructions for renting your accommodation during the 2024 Olympics
Each type of balcony has its Achilles heel
“
It is possible, as a first step, to carry out a visual check, in particular ensuring that the guardrails are properly attached,
” advises Olivier Princivalle, president of the FNAIM of Grand Paris.
He has just sent a note to all of his Ile-de-France members (1,500 condominium trustees, real estate agents, property managers) in order to raise awareness among residents, tenants and owners alike, of the apartments concerned.
The weak points of balconies depend on the material used.
“
We have to concentrate on the feet of the guardrails and their fixings in the front wall.
An iron railing can be subject to corrosion problems.
For those made of stone, you need to look for signs of cracking on the joints or on the stone.
Also be careful in the presence of cullet, which indicates infiltration.
On the balcony itself, it is important to be particularly vigilant about the junction between the facade and the balcony, particularly in the presence of longitudinal cracks,”
explains Benjamin Lefébure.
“
At the slightest alert, notify the trustee,”
he advises.
Even if you haven't noticed anything alarming, watch out for excessive overloads.
“
You have to be reasonable, the balconies are not stands
!
»,
recalls Olivier Princivalle.
For convenience, professionals consider that the acceptable load for a balcony is 350 kg/m².
A threshold which also includes the plants and arrangements that you may have installed.
Now all you have to do is enjoy the festivities of the Paris 2024 Olympic Games while keeping in mind that prudence is the mother of all virtues.