How to Separate Layers of a Roof Underlayment

Remove the roofing that covers the underlayment. If it's metal roofing, remove the screws from the metal with a screw gun, and stack the metal aside for future use. If the roofing is composed of asphalt shingles, remove the shingles by hand, pulling them away from the roof and tearing the nails free.

Staple all layers of underlayment with a hammer stapler. This will secure the underlayment, preventing all layers form releasing at the same time. Space the staples 12 inches apart along the underlayment, especially around the edges.

Cut the individual layers of underlayment with a razor knife. Section the underlayment in 4-foot sections, so that it will peel away easier. Cut carefully, so that you do not cut through all layers of underlayment at the same time.

Heat the layers of underlayment with a heat gun. Begin at the bottom corner of the underlayment, and peel it away. Use a putty knife to separate the layers at the corner. Once the underlayment has been peeled far enough, place a shovel or floor scraper between the layers, forcing them apart.

Continue to heat the underlayment as you separate it. Have a helper hold the heat gun near the separation point, while you continue to force apart the layer with a shovel or scraper.

Reattach remaining underlayment with a hammer stapler. If you choose not to separate and remove all layers of underlayment, then reattach loose material to preserve it for future use.