Why a carport with a tin roof often develops condensation

If condensation forms on the underside of the tin roof on the carport, a relatively small thing was usually not taken into account in the construction. Condensation always forms when warm air meets a colder surface. This effect is reduced or prevented by proper ventilation with air circulation.

Physics and thermals help to understand the effect

The fact that condensation problems can occur on a tin roof is a widespread phenomenon. While more complex substructures are required on heated residential buildings with the need for thermal insulation, the open roof on a carport can easily be protected from this.

In order to design the assembly in such a way that no condensation occurs, it is helpful to understand the basic physical principle of condensation. When warmer air meets colder surfaces, it cools down. This can happen pretty quickly on a cool sheet metal. The moisture in the warm air cannot hold itself and "rains " down. Warm air holds more water molecules than colder air.

In a carport, apart from the normal outside temperature, warm air is generated by an arriving and parked vehicle. The engine is warm and the hood "heats " the air. The second cause of heat can be the floor of the carport. If it is made of soil or covered with stone, warm air can evaporate.

A typical example is the development after a summer rain or when a wet vehicle dries and also wets the ground. The sun and heat combined with a draft heats the air in the carport through evaporation. This air rises and hits the underside of the tin roof. There she almost always cools abruptly and the water molecules are released immediately - they condense.

Interrupt the circulation

In order to prevent condensation under the sheet metal roof, the ascending warm air must either be removed or heated. This happens through a suitable air circulation. Drill is a barrier or a pad under the tin roof. Either he takes the warm air "with " and transports them to "outdoors " or it cools the air from the impact on the sheet.

Tips & Tricks If you can realize roof tags from over thirty degrees on your carport, the natural air circulation is usually enough to avoid condensation. With smaller inclination angles you need to adjust the construction.