Roofing materials have changed as people learned to build with local resources, manufacture durable products, and protect buildings from fire and severe weather. Thatch, clay, wood, slate, metal, and asphalt each shaped the look and performance of roofs in different eras. In the United States, the spread of railroads, industrial production, and new building codes transformed roofing from a regional craft into a broad construction industry. That history also explains why many traditional materials remain in use alongside modern systems.
Flat and low-slope roofs need materials suited to slower drainage. Built-up roofing, often called BUR, uses multiple layers of bitumen—such as asphalt or coal tar—and reinforcing fabrics, topped with a protective surface. This layered approach developed alongside industrial buildings and urban construction, where large roof areas required continuous waterproofing.
BUR systems are distinct from steep-slope shingles. Their details must address drainage, seams, roof edges, drains, and penetrations. Ponding water can contribute to problems if the roof is not designed and maintained to manage drainage. Modern commercial roofing also includes single-ply membranes, modified bitumen, and other systems designed for low-slope applications.
Synthetic Membranes and Contemporary Roofing
During the second half of the 20th century, synthetic materials expanded roofing options. EPDM, a synthetic rubber membrane, became a widely used low-slope roofing product. PVC and TPO membranes also became common in commercial construction. These products are installed in sheets, with seams joined by methods that vary by material and system. Their advantages can include relatively low weight and large, continuous coverage, while their performance depends on seam quality, attachment, drainage, and compatibility with the building.
Modern roofing also includes engineered products that imitate traditional appearances. Composite shingles may be manufactured from polymers or other materials, while concrete tiles offer a tile-like profile. Solar roofing integrates photovoltaic technology into panels or roof products, and conventional roofs may support separate solar arrays. Green roofs use vegetation and growing media over specialized waterproofing and drainage layers. Each system has distinct structural, maintenance, fire, and moisture requirements.
How Roofing Materials Changed Building Design
Roofing materials do more than keep out rain. Their weight affects the framing; their shape and texture influence architectural style; and their fire resistance can affect building safety. A heavy slate or tile roof requires different structural support from a lightweight asphalt shingle roof. A low-slope membrane system needs different drainage details from a steep wood-shingle roof.
Material choice also reflects regional conditions. Snow loads, wind exposure, intense sun, hail, humidity, wildfire risk, and salt air can all affect a roof’s service life. Local building codes set requirements that may address wind resistance, fire classification, structural loading, and energy performance. In the United States, code requirements can differ by jurisdiction, so a product’s general reputation does not replace local code review.
Roofing Materials at a Glance
| Material | Historical role | Common considerations |
|---|---|---|
| Thatch | Early plant-based roofing | Requires specialized installation and fire-conscious maintenance |
| Clay tile | Ancient and enduring fired roofing | Durable, but heavy and dependent on sound support |
| Wood shingles | Widely used in timber-rich regions | Appearance varies with weathering; fire and moisture matter |
| Slate | Long-lived stone roofing used on substantial buildings | Heavy, specialized, and potentially long-lasting |
| Metal | Expanded with industrial sheet-metal production | Performance depends on metal, coating, seams, and installation |
| Asphalt shingles | Mass-market roofing developed in the early 20th century | Broadly available; ratings and service life vary by product |
| Synthetic membranes | Modern systems for low-slope roofs | Seam quality, drainage, and attachment are critical |
Preserving Historic Roofs and Choosing Materials Today
Historic roofs can reveal how a building was constructed and what materials were locally available. Preservation work often begins by identifying the existing material, checking its condition, and documenting roof features such as flashing, ridge details, and drainage. The National Park Service’s preservation guidance emphasizes repairing historic materials where feasible and selecting replacements that respect a building’s character when replacement is necessary.
For a new roof, the most useful comparison considers more than purchase price. Homeowners and building owners can compare expected maintenance, installation requirements, weight, fire and wind ratings, energy characteristics, local code compliance, and the availability of qualified installers. A material’s stated lifespan is not a guarantee; climate, workmanship, ventilation, maintenance, and storm exposure all influence actual performance.
The history of roofing materials is therefore not a simple progression from primitive to advanced. Thatch, tile, slate, wood, metal, asphalt, and membranes each solve different problems. Modern construction continues to use old materials where their qualities make sense, while new manufacturing and building science expand the options. Understanding that history helps explain why the best roof is the one suited to the building, climate, budget, and maintenance plan.