Thermal insulation CASE HISTORY. Rehabilitation of humidity, energetic efficiency upgrading, structural restoration of residential building in Padova

Transcription

1 Rehabilitation of humidity, energetic efficiency upgrading, of residential building in Padova Thermal insulation CASE HISTORY 04

2 2 Rehabilitation of humidity, energetic efficiency upgrading and Rehabilitation of humidity, energetic efficiency upgrading, of residential building in Padova Implementation Year 2009 Works Duration 15 days (including maturation period) No. of Workers One team Surface 300 sqm Plaster Thickness cm The problem The valuable ancient building had a strong rising damp and salts infiltrations causing its obvious structural deterioration and was completely recovered without any demolition operation. The structure, built in bricks with low thermal coefficient and reduced thickness (25 cm), did not have the insulation coefficients compliant with the standards set by the regulations in force (DPR 59/09). Description of the intervention All perimeter walls of the residential building were subject to the intervention. The mansonry wall, made up of traditional hollow bricks of 25cm, plastered on both sides with traditional plaster, was displaying all around rising damp, with obvious phenomena of salts infiltration with consequent detachment of the plaster from the underlying support. Besides solving the humidity issue, the client required an intervention of structural redevelopment which had become of major necessity because of the support structure poor condition. Finally, acknowledging the possibility to access a 55% tax relief provided for by Presidential Decree 59/09, the client has requested that the above described intervention should also have an important thermal energy valence so as to enable the energetic efficiency upgrading of the building and consequently achieve the parameters requested by the regulations.

3 Rehabilitation of humidity, energetic efficiency upgrading and 3 The solution Such an intervention of energetic efficiency upgrading can never be separated from a suitable rehabilitation operation. Therefore, we immediately ruled out the application of mineral or natural fiber panels which, although highly breathable, are subject to humidity uptake. In the same way were discarded the polystyrene or polyurethane based panels which, without undergoing degeneration in contact with humidity and not having high absorption coefficients, still do not have high enough levels of breathability and therefore would not have adequately fulfilled the dehumidification function, essential in this case. Given all these circumstances, the only system with adequate characteristics for the required solution was the DiaSen thermo-dehumidifying system, which provides a rough coat and an anti-salts barrier blocking the salts within the wall and letting out the humidity then absorbed by the Diathonite cork plaster which has the permeability coefficient at water vapor of the natural hydraulic lime ì = 5 and an excellent thermal conductivity, μ =0.045 WmK, similar to that of a panel, it is able to dispose of approximately 1.0 liter of water per m² per hour, thus dehumidifying the wall and securing the good thermal insulation parameters. From the thermal calculations carried out on the stratification of the wall in question it resulted that the required plaster thickness for achieving the values prescribed by the regulations should be of 10 cm. In order to consequently ensure the perfect seal of the plaster on the pre-existing plastered support substrate and to provide major structure stability and strength, it was decided to resort to a further precaution, namely the Polites FRP structural reinforcement network fixed directly and deep in the wall, subsequently drowned in the 10cm of the plaster, creating a real and genuine building cladding/lining. With the use of the Diathonite Evolution thermal plaster it has therefore been possible to solve with a single intervention the problems of the rising damp, and energetic efficiency upgrading, in addition to offering the client the opportunity to fully take advantage of the legally provided 55% tax reduction. PADOVA (PD) DiaSen - Ufficio Tecnico Tipo: Spessore: Massa Superficiale: Trasmittanza: Resistenza Termica: Parete esterna m kg/m² W/m² K m² K/W Sfasamento: 07:44 hh:mm Strato Descrizione PRIMA DELL'INTERVENTO Massa Superficiale Resistenza (kg/m²) Termica (m² K/W) 1 Malta di calce o di calce e cemento Laterizi forati sp.25 cm.rif Malta di calce o di calce e cemento NOTA: Il lato interno della Struttura corrisponde allo Strato in posizione 1. Spessore (m) PADOVA (PD) Tipo: Spessore: Massa Superficiale: Trasmittanza: Resistenza Termica: DiaSen - Ufficio Tecnico Strato Descrizione Parete esterna m kg/m² W/m² K m² K/W Sfasamento: 11:33 hh:mm Massa Superficiale Resistenza (kg/m²) Termica (m² K/W) 1 Malta di calce o di calce e cemento Laterizi forati sp.25 cm.rif Malta di calce o di calce e cemento NOTA: Il lato interno della Struttura corrisponde allo Strato in posizione 1. 1 di 3 DOPO L'INTERVENTO Spessore (m) di 3

4 4 Rehabilitation of humidity, energetic efficiency upgrading and Implementation First Phase Support cleaning and removal of the deteriorated and unstable parts of the background that might otherwise compromise the proper adhesion of the Diathonite Evolution plaster. Second Phase Creation of the WatStop rising dampness barrier, applied by brush in two layers of 2.0 Kg/m 2. The barrier must be built all along the building perimeter and must exceed with minimum 60 cm the maximum level of humidity, so in this case we had to built a barrier of 1.50 m height. Third Phase Positioning of the securing devices for Polites FRP structural reinforcing network.

5 Rehabilitation of humidity, energetic efficiency upgrading and 5 Fourth Phase Application of the Diathonite Evolution plaster using a traditional pneumatic pump for pre-mixed. After having completed a first layer of rough coat of 1.5/2.0 cm, we proceeded with the application of the subsequent layers by applying approximately 2.0/2.5 cm at the time, until we reached the thickness of 6 cm. On top of these layers of 6 cm thickness was then embedded by anchor bolts the Polites FRP network, later covered by Diathonite Evolution plaster up to the final thickness of 10 cm.

6 6 Rehabilitation of humidity, energetic efficiency upgrading and Fifth Phase Once the applied plaster reached the appropriate maturity time, the intervention was completed by the application of Argacem HP macroporous smoothing coat plaster. After the intervention

7 7 Notes

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