Is it necessary for the door between an attached garage and dwelling unit to be less than 2 inches thick?

The requirement for the thickness of a door between an attached garage and a dwelling unit is based on safety and building code regulations that emphasize fire safety and the prevention of carbon monoxide intrusion. While there may be scenarios where a thicker door could be beneficial, there is no strict mandate that such a door must be less than 2 inches thick.

In many building codes, what is crucial is whether the door is a fire-rated door, which is designed to withstand fire and prevent it from spreading between the garage and living spaces. The focus is more on the door's ability to meet fire safety requirements rather than its specific thickness. Furthermore, the presence of insulation and sealing can also be critical in preventing carbon monoxide or other hazardous fumes from entering the dwelling.

Therefore, the correct answer emphasizes that there is flexibility in compliance with door thickness specifications, depending on the door's rating and purpose, rather than a fixed requirement based solely on its dimension.