Red Seal Roofer Practice Exam 2026 – Complete Test Preparation

Certain types of metal roofing are specifically designed to be installed over existing shingles. This is often done to save time and labor costs associated with removing old roofing material. When installing metal roofing over shingles, it’s important that the underlying structure is sound and that any moisture issues are addressed, as metal roofing can trap heat and moisture if not properly ventilated.

Metal roofing is lightweight, which makes it suitable for overlay applications, and it often requires less structural support compared to heavier roofing materials. Additionally, the nature of metal roofing, with its interlocking panels, provides a secure covering that can effectively protect the underlying shingles and the structure beneath.

For the other options, standard asphalt shingles typically require the removal of existing layers before new shingles can be applied, as multiple layers can lead to excessive weight and potential structural issues. Clay tiles are heavy and require a solid substrate, which often necessitates a complete removal of any existing roofing. Built-up roofing, commonly used in flat or low-slope applications, also requires a clean, smooth surface and cannot be effectively adhered over shingles without potential complications. Thus, the advantage of metal roofing in this context makes it the correct choice for installation over existing shingles.