Roofing felt, also called tar paper, is a material that is located between the actual roof and the house and between the last layers of roof material. It is an additional protective layer for the elements, and even a wooden shingle blows off the roof during a storm. It is usually sold in large rolls, 36 inches wide, basically made of polyester or glass fiber fleece impregnated with some kind of water repellent. DIY Building supplies. Roofing felt protects the roof, which ultimately protects your home. It creates a barrier between the planks on the roof and the final roofing material. When strong winds blow water or snow between herpes zoster, this lower layer offers valuable protection.