Typical Renovation Junctions: How to Avoid Thermal Bridges and Condensation

In Construction & Renovation projects, the biggest energy losses and moisture problems rarely come from the insulation itself—they appear at junctions. These “typical details” (wall-to-slab, window reveals, roof edges, balconies, and service penetrations) can create thermal bridges, pushing the surface temperature below the dew point. The result is condensation, damp finishes, and eventually mold. Start with one rule: keep insulation continuous. At floor edges and ring beams, wrap the structure with external insulation or use thermal break elements where continuity is impossible. Balcony slabs are a classic weak point; consider separating the slab with a certified thermal break connector or enclosing the slab with insulation on all feasible sides. Airtightness is the second rule. Even small air leaks transport moisture into colder layers where it condenses. Use an airtight layer on the warm side (taped membranes, plastered masonry, or airtight boards), and connect it carefully around corners and junctions. Seal penetrations for pipes, cables, and ducts with grommets or airtight tapes. Windows require a three-layer approach: an inner airtight/vapor-control seal, a middle insulation layer (low-expansion foam or mineral wool), and an outer weatherproof but vapor-open layer. Position frames within the insulation zone when possible to reduce cold edges. Finally, manage vapor wisely: install vapor barriers only where the assembly requires it, and ensure ventilation and humidity control indoors. With well-designed junction details, Fontana-style renovations stay warm, dry, and durable for years.