Single family House

The Building

The building is a classic piedmont farmhouse made of stone with vaulted brick interiors, dating back to the last century, recently renovated and restored. The roof, originally in poor condition, was completely rebuilt in wood while respecting the original structure to preserve the historical and architectural value of the building. The preservation of traditional shapes and materials, combined with the need to improve energy performance and durability, imposed strict constraints on the choice of technical solutions for the roof. Additionally, the building is located within a green area, partly wooded, which requires interventions that are respectful of the surrounding environment. These factors guided the design of the roof, aimed at ensuring historical compatibility, protection from weather elements, and adequate thermal performance.

The Solution

What is the Solution?

The solution adopted for the roof involved a complete reconstruction using a wooden structure, maintaining the typical features of the original covering. The insulation was carried out with two layers of wood fibre, each 220 mm thick, combined with breathable membranes to ensure airtightness, wind protection, and vapor control, thus preventing infiltration and moisture accumulation. This configuration guarantees high thermal efficiency, durability, and compatibility with the architectural heritage of the building, respecting traditional shapes while improving indoor comfort. Moreover, the use of natural and breathable materials helps preserve a healthy indoor environment.

Why Does it work?

The solution was chosen for its ability to combine high technical performance with respect for the historical and architectural features of the building. The use of a wooden structure and natural insulating materials such as wood fibre makes it possible to preserve the traditional appearance of the roof while ensuring excellent energy efficiency and effective moisture management. From a heritage standpoint, the faithful reconstruction of the original roof allows the building’s identity to be maintained without altering its characteristic shape or materials. In this context, the solution is compatible because it respects the existing envelope, improves indoor comfort, and meets the sustainability and durability requirements necessary for interventions on historic buildings.

PROS

High thermal efficiency
Improved indoor comfort
Use of natural, breathable materials
Moisture regulation and vapor permeability
Low environmental impact
Compatibility with historical architecture
Durability and long service life
Preservation of the building’s original appearance
Healthy indoor environment (no VOC emissions)
Effective protection against weather conditions

CONS

Higher initial cost compared to conventional materials
Thicker insulation layers, which may require design adaptations
Longer installation time due to the multilayer system and attention to detail

Insulation material

Wood fibre boards

Insulation thickness

220

Thermal conductivity

0.038 - 0.047

Health issue

The materials used, such as the Pavatex wood fibre panels, are natural and free of toxic or harmful substances. They do not emit volatile organic compounds (VOCs) or other harmful substances, ensuring a healthy indoor environment for both occupants and workers during installation.

Technical drawings

schede_tecniche-3.pdf

Additional documentation

CC52_peveragno_2.pdf

Installation Method

The insulation was applied during a complete reconstruction of the roof, which was necessary due to the poor condition of the existing covering. The new wooden structure was built respecting the original shapes and proportions of the roof, preserving the building’s external appearance. The wood fibre insulation panels were installed dry over the timber framework, along with breathable membrane layers to ensure airtightness, vapour control, and water protection. Although not fully reversible, the solution was designed to be as non-invasive as possible, avoiding interventions on the load-bearing masonry and ensuring maximum respect for the building’s original architectural features.

Moisture Management and Technical Compatibility

The moisture management strategy for the roof is based on the use of natural, highly breathable materials, such as Pavatex wood fibre insulation panels, combined with specific membranes that ensure airtightness, vapor control, and water resistance. This system allows for controlled vapor diffusion, preventing interstitial condensation and protecting the wooden structure over time. Furthermore, the envelope’s layer composition has been designed to ensure proper hygrothermal balance, enhancing indoor air quality and increasing the overall durability of the roof. The technical compatibility with the historic building is ensured through the use of solutions that respect the original construction features and do not compromise the architectural integrity of the structure.

Airtightness

The strategy to ensure the airtightness of the roof involves the use of specific membranes placed between the insulation layers and the wooden structure. These membranes are carefully sealed with special adhesive tapes at joints and at points where installations or structures pass through, to prevent unwanted air infiltration.

Before retrofit

After retrofit

Before retrofit

Roof thickness

After retrofit

Roof thickness

262

Before retrofit

Roof build-up

FIr wood cladding [20]

After retrofit

Roof build-up

Pavatex Isolair wood fibre insulation board –[22], λ = 0.047 W/m·K, Pavatex Pavatherm wood fibre insulation board – [220], λ = 0.038 W/m·K, Fir wood cladding – thickness [20]

Before retrofit

U-value

3.26

After retrofit

U-value

0.152