How to Seal a Residential Roof

Water and Ice Membrane

• 1

  Lean an extension ladder against the side of the house. Climb the extension ladder to access the roof.

• 2

  Pull the nails holding the roofing shingles to the sheathing with a claw hammer or nail puller. Remove the nails and pull the shingles off the roof from the edge of the roof, three- to six-feet up the slope of the roof. A three-foot roofing deck exposure allows you to install one three-foot-wide ice and water membrane. A six-foot exposure allows you to install two three-foot-wide ice and water membranes.

• 3

  Pry the staples holding the roofing tar paper with a screwdriver. Cut the tar paper with a utility knife to meet the existing roofing shingles.

• 4

  Examine the roofing deck for signs of rot. If rot exists, pull the nails holding the plywood to the rafters with a claw hammer or nail puller. Remove the old sheets and nail in new plywood.

• 5

  Align a self-adhesive ice and water membrane to the roof edge and gutter line. Peel the protective film off the back of the membrane and press it in place. If you are adding a second membrane, line up the membrane with the roof edge and overlapping the first membrane by one inch. Peel the film backing off the membrane and press in place. Make cuts at the ends or around obstacles with a utility knife.

• 6

  Set new roofing shingles back in place, beginning at the roof edge and working up toward the existing shingles. Secure the shingles in place by driving galvanized roofing nails into the shingles. Work row by row until you reach the gutter line of the roof. Repeat the process on the opposite side of the house.

Polyurethane Spray Foam Insulation

• 7

  Go into the attic to access the underside of the roof sheathing.

• 8

  Insert the straw-like nozzle on a can of polyurethane closed-cell spray-foam insulation into the seam between the sheets of plywood sheathing. Depress the trigger and move the nozzle along the seam or gap to seal the roof sheathing and protect it from water entry. Seal around each sheet of plywood inside the attic.

• 9

  Cover nail holes and other cracks or gaps in the attic with closed-cell spray foam.

• 10

  Examine the roof from inside the attic around vent pipes and chimneys. Seal any cracks or gaps around the vent pipes or chimney with closed-cell spray-foam.