Which type of material is preferred to seal the penetration point for a clothes dryer exhaust?

The preferred material to seal the penetration point for a clothes dryer exhaust is noncombustible. This choice is crucial because noncombustible materials do not ignite or burn, thereby providing a safer option in areas that may be exposed to high temperatures or lint accumulation. Noncombustible materials ensure that any potential fire hazards associated with the operation of a dryer are minimized.

In contrast, materials such as plastic and wood can pose significant risks; plastic can melt or become deformed under high heat, while wood is combustible and can easily catch fire. Fiberglass, while it may be fire-resistant to some extent, does not provide the same level of assurance as truly noncombustible materials. Therefore, using noncombustible materials is essential for maintaining safety and adherence to building codes in dryer exhaust installations.