Thermal Bridging and Moisture Accumulation

Thermal Bridging

Thermal bridging occurs when a highly conductive material, such as metal or concrete, extends through a building envelope, creating a pathway for heat to escape from the interior. This can lead to increased energy costs and discomfort for occupants.

Moisture Accumulation

In addition to thermal bridging, moisture accumulation can occur within walls due to:

* **Condensation:** When warm, humid air comes into contact with a cold surface, it condenses into liquid water.
* **Air leakage:** Moisture-laden air can enter the wall cavity through cracks or gaps in the building envelope.
* **Water intrusion:** Water can penetrate the wall from outside through leaks or damage to the exterior cladding.

How Much Moisture is OK in Walls?

Moisture in walls can lead to mold growth, structural damage, and reduced insulation effectiveness. Generally, moisture content in walls should be below 15% to minimize these risks.

Solutions

To prevent and mitigate thermal bridging and moisture accumulation, several solutions are available:

* **Insulation:** Adequate insulation can reduce heat flow through thermal bridges and prevent condensation.
* **Vapor Barriers:** Vapor barriers, such as polyethylene or aluminum foil, can prevent moisture-laden air from entering the wall cavity.
* **Air Sealing:** Sealing gaps and cracks in the building envelope can prevent air leakage and moisture infiltration.
* **Proper Flashing:** Flashing around windows, doors, and other openings helps direct water away from the wall.