Mastic asphalt in buildings and civil works – typical application Mastic asphalt is normally used for which primary purpose on site?

Introduction:
Mastic asphalt is a dense, void-free asphaltic material prepared from bitumen and carefully graded mineral fillers. Its key engineering value lies in forming seamless, impermeable layers. The question asks for the most typical, primary site use.

Given Data / Assumptions:

• We consider standard building and civil applications.
• “Normally used” implies the common, dominant application.

Concept / Approach:

When applied hot and finished properly, mastic asphalt creates a monolithic, watertight sheet that adheres well to substrates. This makes it ideal for roofs, podium decks, basements, and water-retaining or water-excluding structures where impermeability is vital.

Step-by-Step Solution:

Verification / Alternative check:

Specifications for roofing and tanking frequently list mastic asphalt grades as waterproofing layers, sometimes protected with tiles or screeds. Sound or fire insulation are secondary or unrelated functions compared with its waterproofing role.

Why Other Options Are Wrong:

Sound insulation: Not a primary function; mass helps, but better acoustic systems exist.
Fire proofing: While asphalt has some fire-related considerations, it is not primarily a fireproofing material.
None of these: Incorrect because waterproofing is a standard, mainstream use.

Common Pitfalls:

Confusing mastic asphalt (dense, void-free) with asphalt concrete or polymeric membranes; overlooking the need for proper expansion detailing and protection from high service temperatures.

Final Answer:

Waterproofing