Gambrel roofs, the ones that look like barns, may seem like a difficult roof to install shingles on. The slope changes on each side of the roof make it seem like a daunting task, but it’s actually as easy as working on a normal roof. Below, we’ll walk you through how to install asphalt shingles on a gambrel roof.
Pick A Warm Day
The tarred sides of asphalt shingles are flexible and easier to work with when they’re warm. So you should choose a warm summer day to install them.
Determine How Many Shingles You’ll Need
Usually a square of asphalt shingles covers a 10 ft by 10 ft area, or 100 square feet. Measure your roof, adding the square footage of every section and adding 5% for waste. Then divide the total by 100 to get the number of squares needed.
Lay the First Shingle
Start by laying the first asphalt shingle to the outer corner of the lowest slopping face of the Gambrel roof. Then use a nail gun to secure the shingle to the decking. Use three nails through the upper portion of the shingle.
Add Another Shingle
Lay another shingle next to the first one. Secure it with the nail gun like you did the previous shingle. You’ll continue laying shingles end to end until you reach the other side of the roof face.
Trim the Last Shingle
Once you get to the end of the roof face, you’ll have to trim the last shingle to fit. Do this by scoring the tar side with a razor blade and then snapping the shingle in your hands.
Start the Second Tier
Next, trim the first asphalt shingle of the second tier in half and overlap the first tier by as much as the manufacturer’s specifications say. Lay the rest of the shingles of the second tier and trim the last shingle to fit.
Start the Third Tier
Lay the third tier with a whole shingle. Continue to lay courses of shingles, alternating from half a shingle to a whole shingle.
Laying on the Slope Change
When you reach the slope change on the roof, you’ll continue as normal.
Finishing the Ridge
Once you get to the ridge, or horizontal peak, you’re done with the three-tab asphalt shingles. So you’ll cap off the ridge with asphalt ridge caps (square shingles). And that’s it. Just remember to be careful when installing shingles yourself. It’s best to have someone help you and be on the lookout in case you have an accident.