Which roofing type requires no underlayment?

Which roofing type requires no underlayment?

• A. Asphalt shingles
• B. Wood shingles
• C. Wood shakes
• D. Metal tiles

Answer: (B)

Wood shingles are designed to be installed directly on the roof deck with an overlap that sheds water, serving as the primary waterproofing layer. When laid properly, the shingles themselves provide the weather barrier, so a separate underlayment isn’t required. Asphalt shingles, metal tile, and wood shakes rely on an additional underlayment to provide a secondary moisture barrier and to compensate for decking imperfections or wind-driven rain, which is why they typically use underlayment. Therefore, wood shingles are the roofing type that commonly requires no underlayment.

Wood shingles are designed to be installed directly on the roof deck with an overlap that sheds water, serving as the primary waterproofing layer. When laid properly, the shingles themselves provide the weather barrier, so a separate underlayment isn’t required. Asphalt shingles, metal tile, and wood shakes rely on an additional underlayment to provide a secondary moisture barrier and to compensate for decking imperfections or wind-driven rain, which is why they typically use underlayment. Therefore, wood shingles are the roofing type that commonly requires no underlayment.