157 Square Inches
***** How to apply asphalt roofing *****
You will need sharp scissors, a tacky wood glue (or hot glue gun, but it's not necessary) and a good eye for symmetry.
Start by laying the first row upside down flush along the bottom row of your roofing area. Start with the left side of your strip, and cut off any excess. Lay the second row parallel to it and translated up by about half an inch, to line up the top of the tab slot with thetop of the previous row. The edge of the shingle strip should line up with the edge of the roof, but likely only for this row. Then, lay the third row staggered over to the left by about half a shingle, lined up the same way, with a small section of the strip overhanging the roof. Cut this section off, trimmed to the roof edge.
Lay the fourth row so that it is lined up with the second row's shingles as exactly as possible, and then the fifth row lined up with the third, and so on.
Optional: For a sturdier roof bond, use staples to secure the strip, on sections which will be covered by the next row.
When nearing the roof peak, cut a strip to meet flush with the edge if necessary. Make sure the opposite side of the roof is finished the same way before continuing.
To cap the roof, cut off single squares, fold them evenly in half, and glue them overlapping the previous shingle by one quarter inch along the roof peak.
For a neat, pressed look to your freshly glued shingles, lay a board over the top and apply weight until the shingles dry.