How Much To Overlap Roofing Tar Paper

Some roofing felts are actually glued down.

How much to overlap roofing tar paper.

Make sure the rolls overlap by at least four inches and staple them into place on the wood. Felt underlayment can overlap more than 2 inches to provide an adequate barrier. Repeat this until the entire roof is covered. The overlap of 3 8 should be followed consistently for a smooth look once the shingles are installed.

For example if its length is 120 inches 10 ft and its width is 240 inches 20 ft the area is 28 800 square inches 200 sq ft. Get help to lay the first sheet onto the roof. Step 6 overlap next roll. Overlap top of foundation.

Measure the width and height of each section separately. If your roof pitch is 3 12 or 4 12 multiply by 1 25. Even if there s older tar paper in place you should simply rip it off and replace it. Overlapping up to 6 inches can provide a superior felt layer.

Multiply the total area determined in step one by a correction factor to account for the roof pitch. When unrolling the next adjacent roll allow for at least a two inch overlap. And even though it is thinner it is just as strong as felt and less resistant to ripping. All nails should be placed at least 12 inches away from the center of the valley.

Start by measuring the length and width of one side of the roof in inches. Underlayment should cover the entire roof deck. When transitioning into the valley underlayment should overlap the ice and water shield previously installed along the valley by 6 8 inches. If you have a vertical seam where one piece ends and another starts make the overlap at least 6 inches.

As long as the wood on your roof is in good condition you can go ahead and put tar paper down. The answer is the number of square feet of. This paper is a new and in some aspects improved material for roofing underlayment. Continue this for each surface of your roof.

This correction factor will take into account the greater area of the roof due to the pitch. It s thinner lighter and a single roll can cover much more area than a similarly sized roll of felt. However the additional overlap may alter the spacing of the felt courses relative to the sheathing creating problematic conditions for fastening the felt to the sheathing. This will help give you a moisture barrier on the roof.

There should be no wrinkles or other spots that could catch moisture and cause problems. Secure the outside edges with plastic capped roofing nails at 12 inch intervals. Usually 2 inches is plenty on a horizontal seam. The vertical overlap should be at least 2 feet or 24 inches.

Fit the first sheet. There are pre printed lines on the tar paper that help show you where to end the overlap. Multiply the width by the height for the square footage of each section then add the totals. Nail the two rolls in the overlap at 12 inch intervals.

For roof pitches of 5 12 to 7 12 use a factor of 1 3. Roll the roof paper up and over the peak.