RE-FESTA: A new reinforcement system using tension-activated timber for the rapid, safe and sustainable refurbishment of ceramic floor slabs

In Catalonia, there is a significant stock of housing built, mainly between the 1940s and the late 1960s, with ceramic floor slabs. These floors are part of the so-called autarkic slab systems, which became widespread in the post-war context, marked by restrictions on the use of steel following the 1941 decree and by the availability of ceramic materials. Today, it is estimated that there are around 130,000 dwellings with this construction typology, many of which are between 65 and 85 years old. The passage of time, material deterioration and accumulated damage make intervention necessary—not only to ensure structural safety, but also to be compatible with occupied buildings, where speed of execution, ease of access and minimisation of disruption to occupants are key factors.

In this context, the RE-FESTA project (for its name in Catalan, REhabilitació amb Fusta EStructural TensoActivada) proposes an innovative alternative based on prestressed or stress-activated timber reinforcements applied to existing ceramic slabs. Through a controlled stressing process, the timber elements become structurally activated and begin to work in conjunction with the slab, improving its load-bearing capacity. The solution combines a renewable, low environmental impact material such as timber with a prestressing technique adapted to the specific characteristics of ceramic slabs.

This proposal adapts to different existing floor configurations, allows for rapid execution with minimal disruption during works and also contributes to improving the acoustic and thermal insulation of the upgraded buildings. In this way, it provides an integrated response to the structural, construction and environmental challenges associated with the rehabilitation of the existing building stock.

The result stands out for its potential for large-scale replication and its alignment with European objectives for building renovation and sector transition. The ability to operate in occupied buildings and the use of timber as the main structural material represent a significant advancement over conventional strengthening systems and open the door to new construction solutions with strong market potential.

Budget and Funding

RE-FESTA is part of the Industry of Knowledge 2024 call, under modality A. Llavor (2024 LLAV 00121), and has been funded by the Agency for Management of University and Research Grants (AGAUR) with a budget of €20,000. The project lasted six months (December 2024 – June 2025).