A 37.500 m2 scaffolding system to restore the Lakanal high school (92)

As part of the restoration of the Lakanal high school, a listed historic monument, located in Sceaux, TUBESCA-COMABI, the European leader in access and work at height solutions, has designed a 37 m500 scaffolding system.

An extraordinary site due to its technical, logistical and organizational constraints on an active site. The latter entered its last phase with in particular the restoration of the large chimney.

Design of a tailor-made scaffolding for the restoration of the large chimney

Lakanal High School has been the subject of exterior restoration work, cut stone, roofing and carpentry since 2014. The work is carried out in 3 phases at the rate of one phase per year.

Also, the third phase of renovation which started last February and concerned the right aid of the building, is currently ending with the restoration of the large chimney still in service. The TUBESCA-COMABI design office therefore designed a new self-stable scaffolding, without a fulcrum around the 33m high chimney weakened by time. The engineers created, in 2 weeks, a super scaffolding gantry making it possible to fully take up the efforts of the self-stable scaffolding. The installation will be spread over 3 weeks with the intervention of 4 specialized fitters.

Technical solutions to meet time and volume constraints

TUBESCA-COMABI has designed for this complex site, a structure made of foot scaffolding and suspended scaffolding with overhangs on certain levels. "The buildings were scaffolded in 3 parts of 10 to 15 m000 of scaffolding each" explains Erwan Thomas, TUBESCA-COMABI Key Account Manager. The proposed solution had to take into account the specificities of the various trades brought to intervene (repair of the cover, renovation of the facades ...). Thus 2 scaffolding classes were posed. A class 2 scaffolding for the maintenance of red brick and a class 3 scaffolding "M5" for changes of cut stone to secure and facilitate their transport. The latter was installed on most of the site because it is designed in different lengths, it adapts to any type of site (facade, roof and offset) and offers optimal conditioning in trucks during transport.

The Lakanal project: an organizational, logistical and human challenge

On this major project, the challenges to be met are mainly logistical and human. As the site is still occupied, TUBESCA-COMABI is deploying rapid and fluid assembly systems to restore the building on time. "We had 2 times 2 weeks to erect 12m000 of scaffolding during the school holidays of February and April" explains Erwan Thomas. To ensure the smooth running of the site, 2 fitters had to be coordinated.

In addition, these time constraints mean that the 7 companies present on the site, or more than 200 people, must intervene at the same time. TUBESCA-COMABI has thus deployed technical solutions adapted to the different trades brought to work on the same parts of the scaffolding, while ensuring a very strong connection with the other trades, the fitters and their design office. “We had to isolate the upper and lower parts of our scaffolding to allow the roofer to work without disturbing the masons working on the facade below. This implies setting up a fluid communication between the different stakeholders since we had to know precisely when each intervention ends in order to be able to dismantle the following interventions in time and in hours ”continues Erwan Thomas.