How Much To Overlap Roofing Tar Paper

The answer is the number of square feet of.

How much to overlap roofing tar paper. Overlapping up to 6 inches can provide a superior felt layer. 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. Even if there s older tar paper in place you should simply rip it off and replace it. This paper is a new and in some aspects improved material for roofing underlayment.

Usually 2 inches is plenty on a horizontal seam. Step 6 overlap next roll. Multiply the width by the height for the square footage of each section then add the totals. 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. Nail the two rolls in the overlap at 12 inch intervals. Make sure the rolls overlap by at least four inches and staple them into place on the wood. Afterward multiply them to calculate the area.

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. And even though it is thinner it is just as strong as felt and less resistant to ripping. When unrolling the next adjacent roll allow for at least a two inch overlap.

Start by measuring the length and width of one side of the roof in inches. Felt underlayment can overlap more than 2 inches to provide an adequate barrier. This will help give you a moisture barrier on the roof. This correction factor will take into account the greater area of the roof due to the pitch.

Be sure the tar paper lies in flat strips that are absolutely smooth. Secure the outside edges with plastic capped roofing nails at 12 inch intervals. As long as the wood on your roof is in good condition you can go ahead and put tar paper down. Multiply the total area determined in step one by a correction factor to account for the roof pitch.

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. The vertical overlap should be at least 2 feet or 24 inches. For roof pitches of 5 12 to 7 12 use a factor of 1 3. Some roofing felts are actually glued down.

It s thinner lighter and a single roll can cover much more area than a similarly sized roll of felt. Measure the width and height of each section separately. Step 5 secure ends. All nails should be placed at least 12 inches away from the center of the valley.

Get help to lay the first sheet onto the roof. Continue this for each surface of your roof. Fit the first sheet. Underlayment should cover the entire roof deck.

If your roof pitch is 3 12 or 4 12 multiply by 1 25. There are pre printed lines on the tar paper that help show you where to end the overlap.