If your roof is not uniform and has different sections of different sizes, measure 1 section at a time. Multiply each length and width to find the area of each section. Add the section areas together to find the total area of the roof. Get an extra 5-10% of material to account for overhangs and overlap.

Wear footwear with proper grip on the soles. Don’t go up on your roof with canvas shoes or sneakers on.

Wear long pants, work gloves, and shoes with deep ridges so they have a good grip. Never go on top of the roof to hose it. Hose it from a safe area where you are in no danger of falling from the roof. Make sure your roof is completely dry before installing your roofing. Have a friend with you to help or alert other people in case you lose your footing on the roof. If you have gutters, clear them out with gloves and a bucket.

If you’re doing this in the winter, roll your roofing sheets out in a garage. Cold weather damages roofing sheets. Cut pieces into 12–18 feet (3. 7–5. 5 m) sections and lay them out flat in your yard. Let them flatten in the sun for a day. If the temperature drops below 45 °F (7 °C), keep the roofing in your garage or inside.

Avoid using eaves as guides as they are not necessarily placed at the same height across the roof.

Apply the cement in stages. Do the bottom part of the roof before you start working on that section, apply it to the middle before you start working there, and so on. Use the chalk lines as the borders of each section. Always wear gloves when working with roofing cement. Read the instructions on the side of the roofing cement container before you begin.

The first layer should cover the roof as far as the chalk line.

Be careful when working with a hammer and nails on a roof. Make sure you have a stable grip on the roof.

Draw the chalk line across the length of the roof.

When nailing the second layer into the roof, make sure you nail the first and second layers together. Repeat this process for the rest of the roof.

If you can lift the edges, use some more cement to seal them in place.

Once the roof is clean, you’re finished.