Which type of construction is least likely to provide a strong resistance to fire?

Type 5 construction is known for being the least resistant to fire among the construction types listed. This type typically utilizes lightweight materials such as wood framing and often does not include fire-rated walls or advanced fire-resistance features found in more robust construction types. As a result, Type 5 buildings can be significantly more vulnerable to fire spread due to the combustible nature of their primary materials.

In contrast, Type 1 construction features non-combustible materials and is designed to withstand higher temperatures for longer periods, making it highly fire-resistant. Type 3 construction has a mix of combustible and non-combustible materials but typically incorporates fire-resistive elements that mitigate the risk of fire spread. Type 4 construction, or heavy timber, includes substantial wooden elements treated for fire resistance, also providing a higher level of fire safety.

Thus, while other constructions include materials and designs aimed at enhancing fire resistance, Type 5 construction's reliance on lighter, combustible materials makes it the least effective in resisting fire.