Insulating an old house requires a thoughtful approach that considers the building's structural integrity, its original characteristics, and the construction techniques of the era. A professional assessment is essential before undertaking the work.
Initial Assessment
Complete Inspection
Before any insulation work, a thorough building inspection is necessary. This assessment identifies the current state of insulation, moisture problems, air leaks, and particularities of the original construction.
Understanding the Existing System
Old houses were often designed to "breathe," allowing moisture to evacuate naturally. It's crucial to understand this system before adding insulation to avoid creating moisture problems.
Priority Zones
The Attic
The attic is generally the first zone to insulate because it's where most heat escapes. Adding blown cellulose or spray foam can significantly improve energy efficiency.
Basement and Foundations
Old house basements and crawl spaces are often poorly insulated or not at all. Interior insulation with spray foam is often the best solution.
Walls
Wall insulation is more complex in old houses. Several options exist: foam injection into cavities, interior insulation, or exterior insulation depending on the situation.
Adapted Techniques
Spray Foam
Spray foam is particularly effective for old houses because it perfectly conforms to irregular shapes and seals air leaks. It can be applied on various surfaces without requiring major modifications.
Blown Cellulose
For attics and certain wall cavities, blown cellulose offers an economical and effective solution that allows the building to retain some vapor permeability.
Important Considerations
Ventilation
When improving an old house's air-tightness, it often becomes necessary to also improve ventilation to maintain good indoor air quality.
Heritage Preservation
For heritage homes, specific techniques may be necessary to respect architectural characteristics while improving energy efficiency.
Phased Approach
It's not necessary to do everything at once. A phased approach, starting with the most important areas, allows you to spread costs while achieving progressive improvements in comfort and energy efficiency.