There are several types of roofs commonly used in construction, each with their own unique features and advantages. Metal roofs are known for their durability, fire resistance, and low maintenance requirements. Built-up roofs consist of multiple layers of bitumen and felt, making them highly resistant to water and weather damage. Modified Bitumen roofs are similar, but with added polymer modifiers to increase flexibility and strength. Single-ply roofs are made of a single layer of membrane, such as TPO or PVC, and offer excellent resistance to UV rays and weathering. Finally, spray foam roofs are made of polyurethane foam applied to the roof surface and offer excellent insulation and waterproofing properties. Each roof type has its own strengths and weaknesses, and the choice of which to use depends on factors such as climate, building type, and budget.