Bituminous Products – Typical Use of Bitumen Felt in Building Construction On building sites, factory-made bitumen felt sheets are commonly used for which protective functions in walls and roofs?

Introduction:
Bitumen felt is a factory-produced sheet consisting of a fibrous base saturated/impregnated with bitumen. It is ubiquitous in building envelopes for controlling moisture ingress. This question tests whether you can map the product to its realistic functions on site.

Given Data / Assumptions:

• Product: bitumen felt rolls/sheets.
• Use cases: horizontal damp proof courses (DPCs), roofing membranes, flashings.
• Performance depends on grade, laps, priming, and protection layers.

Concept / Approach:

Bitumen felt serves as a moisture barrier both as a DPC (to stop capillary rise) and as a waterproofing membrane on roofs/terraces when properly laid with laps, primers, and protection. Therefore, the realistic answer is that it can be used for both functions depending on design details.

Step-by-Step Solution:

Verification / Alternative check:

Standard practice notes and codes list bituminous felt among accepted DPC materials and as part of traditional built-up roofing before modern membranes.

Why Other Options Are Wrong:

Restricting to one function ignores common usage. “Neither” and “sound insulation only” do not reflect actual site applications.

Common Pitfalls:

Assuming all bituminous sheets are waterproofing only; overlooking their long-standing role as DPC in walls.

Final Answer:

Both damp proofing and water proofing depending on detailing