What is required for concealed vents located less than 1-1/2" from framing?

For concealed vents situated less than 1-1/2 inches from framing, the requirement of a minimum 16 gauge metal shield is crucial for ensuring fire safety and compliance with building codes. This metal shield serves several important functions.

First, it acts as a barrier that can withstand higher temperatures if a fire were to occur, effectively protecting the framing materials from heat and potential ignition. A metal shield also helps to prevent the transfer of flames or hot gases, minimizing the risk of a fire spreading through the vent space into the structural elements of a building.

Additionally, using minimum gauge specifications like 16 gauge ensures that the shield has the necessary structural integrity to remain intact during a fire incident. This level of protection reflects industry standards designed to enhance safety in mechanical and HVAC systems, particularly in areas where vents might be in closer proximity to combustible materials.

In contrast, options like a plastic cover or wooden supports would not provide the necessary heat resistance or structural integrity that is required by fire codes. While a metal pipe with seals may offer some benefits for other applications, it does not fulfill the specific requirement for concealed vents near framing.