Based on the needs of the owners, a family with three members, residing in a single-family semi-detached house on the ground floor, of approximately 50m2, its expansion in height is proposed, doubling its surface.
The proposal consists of dismantling the concrete tile roof on ceramic dovetail partitions supported on the existing slab (ground floor ceiling), and building a new height on top of it, respecting the perimeter of the façade on the ground floor, with the only except for the creation of a porch at the entrance.
In view of the type of construction of the existing building - load-bearing walls of solid brick and reinforced concrete slab - and once the relevant inspections were carried out on the edge of the slab (ground floor ceiling), in which the non-existence of of a perimeter strap; The property is proposed to execute the new structure for the first floor and covered with cross-laminated wood panels (CLT: Cross Laminated Timber) in walls and slabs; to ensure, as a priority, that the new load transmission is adequately distributed over the existing structure and allows the entire structural assembly to be correctly braced.
The CLT structural system achieves high performance and advantages over conventional ones, based on reinforced concrete and/or metal structure, which must also be supplemented with a main sheet or support for the façade, with the consequent increase in weight, and which in These systems would force the need to reinforce the original foundation.
It is enough to present some factors or advantages of the CLT system to justify your choice, making it the most economical option:
- Drastic reduction in the weight of the new building body along with its balanced distribution over the existing structure, without the need to reinforce the foundation.
- Independent and clean structural solution on site, without affecting or altering the adjacent semi-detached house.
- Reduction of execution times.
- Condition and quality of a dry work.
- Optimization of the useful surface area and free height in the expanded floor plan (reduced thicknesses in the wall panels and slabs)
- Arrangement of a container or support precisely adjusted to the project as a continuous and flat base for the execution of the rest of the work.
- The structural wall panels form, in addition, the main façade sheet that serves as continuous and homogeneous direct support for the placement of thermal insulation on the outside (in our case SATE with 10cm thick EPS), eliminating thermal bridges and achieving a integral thermal envelope by connecting directly to the exterior carpentry without the need for pre-fences.
The proven experience of the company AlterMATERIA in the structural calculation, dismantling, supply and assembly of cross-laminated wood was decisive in its choice, managing to carry out the complete structure in one week, with a highly precise and simple installation.
The assembly of the cross-laminated panels enables exact planning of the work, without interruptions between work phases; Furthermore, allowing the existing home on the ground floor to be quickly protected, this being a very relevant aspect for the property.
Until the beginning of the interior conditioning work, the main phases of the work have been:
- Disassembly of the roof and its dovecote partitions (3 days),
- Immediately afterwards, the assembly of the CLT structure: a 60 mm thick horizontal panel is fixed to the existing floor on battens anchored to the reinforced concrete floor, increasing the inertia of the existing joists and the horizontal assembly; On it, the first floor vertical panels (72 mm) are mounted as support for the first floor slab panel (95 mm), finally the structure of the inclined roof is formalized by forming a slope with vertical walls and on these the inclined cross-laminated panel (1 week).
- Without interruption, installation of insulation and waterproofing, along with roof finishes and roof finishes, reusing the existing dismantled tile (2 weeks).
- Next, the installation of the exterior carpentry and execution of the SATE system with 10 cm thick expanded polystyrene insulation and a layer of plastering with render (Baumit integral system) (3 weeks).
The organization of a work with this system has served so that, once the structure is finished, and the façade and roof envelope has been executed, the available set serves as a large closed, protected and conditioned container to comfortably carry out the interior renovation work of the existing ground floor and the new upper floor: the partitioning made up of laminated plasterboard, installations, interior carpentry, coatings and finishes, executed in a short period of time and without any complications.
As a fundamental fact of the great advantage of correctly executing the thermal envelope on the recent roof and façade - a closed and homogeneous base formalized by cross-laminated wood panels - during this winter the property has not needed to use heating on the floor. enlarged top.
CREDITS:
Extension of semi-detached single-family home in El Molar (Madrid)
Year of expansion work: 2015
Promoter: Yolanda Sanz Martín
Architect: Ricardo López López
Technical Architect: Lucía Gigante Benavente
Cross-laminated wood structure:
- Manufacturer: KLH
- Calculation and assembly: AlterMATERIA
Builder: Camarero García, Reformas y Proyectos, SL
