Understanding 15 lb Roofing Felt: Fast-Track Guide to Roofing EssentialsSarah ThompsonSep 09, 2025Table of ContentsTips 1:FAQTable of ContentsTips 1FAQFree Smart Home PlannerAI-Powered smart home design software 2025Home Design for FreeRoofing felt is a critical underlayment material that plays a vital role in protecting your home from moisture and aiding in proper roof installation. Among the various types available, 15 lb roofing felt is one of the most common choices, especially for residential roofing. This product is essentially a heavy-duty paper impregnated with asphalt, designed to create a waterproof barrier between your roof sheathing and the outer roofing material (like shingles).Historically, the “15 lb” designation referred to the weight of one 100-square-foot roll of roofing felt. However, due to changes in manufacturing processes, actual weights might now be slightly lower. Despite this, 15 lb roofing felt remains a standard for many roofing projects, favored for its balance between durability, flexibility, and cost. It is thinner and lighter than 30 lb felt, making it easier to handle and install, though less robust for heavy-duty applications.As an interior designer, I often consider the impact of roofing decisions on a home's overall comfort, moisture levels, and longevity. Well-chosen roofing felt can prevent leaks that might lead to issues such as warped flooring, peeling paint, or mold—problems that significantly affect both aesthetics and health indoors. Ensuring correct installation of underlayment like 15 lb roofing felt can contribute to a more secure and enjoyable living space. Professionals often leverage planning tools such as a home designer platform to map out the interaction between the roofing system and other home components, optimizing both function and interior comfort.Tips 1:Always check local building codes and manufacturer recommendations before selecting your roofing felt. While 15 lb is suitable for many applications, in areas prone to severe weather, upgrading to heavier felt or synthetic alternatives may be recommended.FAQQ: What is 15 lb roofing felt made of? A: 15 lb roofing felt is typically made from a cellulose (wood or plant fiber) base saturated with asphalt, which provides water resistance. Q: Can 15 lb felt be used under all types of roofing shingles? A: Yes, it's commonly used under asphalt shingles, wood shakes, and some types of metal roofing, but always confirm with your roofing manufacturer. Q: Is there a difference between 15 lb and 30 lb roofing felt? A: Yes, 30 lb felt is thicker, heavier, and more durable than 15 lb, making it better suited for roofs exposed to harsher conditions. Q: How long does 15 lb roofing felt last? A: When installed correctly and protected by roofing material, it can last the life of your roof. Exposed felt (not covered) deteriorates quickly. Q: Do I need professional installation for roofing felt? A: While DIY installation is possible for smaller projects, professional installation ensures proper layering and sealing, minimizing future repair needs.Home Design for FreePlease check with customer service before testing new feature.