Question

3 tries left
what is one drawback to a cast - iron building?
it cannot span large spaces.
it is not heat and fire resistant.
it does not allow for lighter exterior walls.
it does not allow for flexible interior spaces.

Explanation:

Cast - iron is a brittle material. In building construction, one of its significant drawbacks is its brittleness which affects its ability to handle certain structural requirements. Let's analyze each option:

• Option 1: Cast - iron can be used in ways to span relatively large spaces (e.g., in some early - stage large - span roof or bridge - like structures with proper design). So, this is not a correct drawback.
• Option 2: Cast - iron has good heat and fire - resistant properties. It does not easily melt or lose its structural integrity quickly in the face of heat, so this option is incorrect.
• Option 3: Cast - iron's use in building frames (e.g., in the form of columns) can actually allow for lighter exterior walls as the load - bearing function is shifted to the cast - iron structure. So, this option is wrong.
• Option 4: Due to the brittleness of cast - iron, it is not very flexible in accommodating changes in interior space requirements. For example, if one wants to make significant alterations to interior partitions or open up large interior spaces in a way that requires the structure to have some degree of flexibility (which cast - iron, as a brittle material, cannot easily provide), it is a drawback.

Answer:

It does not allow for flexible interior spaces.