Answering Your Questions About Roofing

How to Lay Gambrel Barn-Roof Shingles

by Donald Evans

If you have a gambrel roof, asphalt shingles will add a layer of protection. A gambrel roof, or barn-style roof, has multiple slopes with steep pitches transitioning into smaller pitches on each side. The design allows for extra space at the top. A beginning DIY person can tackle this project, provided they aren't afraid of heights. Here are tips to shingle a gambrel barn roof.

Prepare to Work

For this project, you will need: 

  • work gloves
  • ladder
  • tape measure
  • utility knife
  • chalk
  • straight edge
  • ridge caps
  • drip edge
  • roofing cement
  • galvanized roofing nails

Place a ladder on a flat surface and get an assistant to hold it while you climb the roof, if needed. Secure a safety harness to one side for extra security. Try to work on a warm day so the shingles are more flexible.

A standard shingle covers a ten-by-ten square-foot section. Measure each roof section to get the square footage for the number of shingles you need. Add 5% to this figure for waste and divide the total square footage by one hundred.

Install the Starter Shingle Course

Start laying shingles on the lowest slope. Install a drip edge to protect the roof from water damage. Use the nail gun to install three evenly spaced nails in the non-decorative part of the shingle. Leave a half-inch overlap on the drip edge.

Place the second shingle next to the first shingle in and secure it to the roof in the same manner. Keep laying shingles until you reach the end of the row. Trim shingles at the end of the row with the utility knife.

Lay Additional Courses

Cut the first shingle for the second row with the utitily knife to overlap the starter course. Lay the first shingle of the second row over the last shingle of the first row, leaving an overlap. The shingles should have ridges on them to use a guides for overlap. Complete the rest of the row and trim the last shingle to fit.

Start the third row over the middle of the last shingle of the second row. Finish the row, laying each shingle in the middle of the shingle below, and trim the shingle.

Continue laying rows of shingles until you cover all of the slopes. If you reach a ridge, nail ridge caps over the last row of shingles. When you lay shingles on slopes, they will stand, but they should eventually fall in place.

Installing shingles yourself saves you money. If you don't feel comfortable completing this task, or if the roof is very high, consider hiring a roofer such as Gulfside Roofing Inc.