Shingles, shakes, and other roofing materials cannot perform to their maximum capacity without suitable underlayment. Because self-adhesive roof underlayment should not be used over existing roofing materials, you must first remove the old shingles. Then, lay down the self-adhesive piece of roofing material. The old shingles should be removed using a hammer and pry bar. Make sure that you do not damage the new shingle when removing the old one. Then, lay the self-adhesive piece of roofing material over the existing shingles or other surface. Self-adhesive roofing products are easy to use and install. They do not require any special tools for installation. The adhesive on the back of the membrane sticks to the metal in your house so it can hold up against weather conditions. You can also move it around if needed. There is no need to screw it into the ceiling or trim of your home. Underlayments will help give your roof proper support and insulation. It will also allow the roofing material to adhere properly to your home. Without this layer, the shingles or other roofing materials would be unable to withstand wind, rain, and other elements that cause damage to roofs. You should consider how much you want to spend before choosing an underlayment for your roof.