Overlapping up to 6 inches can provide a superior felt layer.
How much to overlap roofing tar paper.
It s thinner lighter and a single roll can cover much more area than a similarly sized roll of felt.
Multiply the total area determined in step one by a correction factor to account for the roof pitch.
The vertical overlap should be at least 2 feet or 24 inches.
Usually 2 inches is plenty on a horizontal seam.
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.
Afterward multiply them to calculate the area.
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.
When unrolling the next adjacent roll allow for at least a two inch overlap.
Underlayment should cover the entire roof deck.
Even if there s older tar paper in place you should simply rip it off and replace it.
And even though it is thinner it is just as strong as felt and less resistant to ripping.
Step 5 secure ends.
Fit the first sheet.
Overlap top of foundation.
Be sure the tar paper lies in flat strips that are absolutely smooth.
Nail the two rolls in the overlap at 12 inch intervals.
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.
Roll the roof paper up and over the peak.
Measure the width and height of each section separately.
The overlap of 3 8 should be followed consistently for a smooth look once the shingles are installed.
This correction factor will take into account the greater area of the roof due to the pitch.
Repeat this until the entire roof is covered.
Secure the outside edges with plastic capped roofing nails at 12 inch intervals.
For roof pitches of 5 12 to 7 12 use a factor of 1 3.
This will help give you a moisture barrier on the roof.
Start by measuring the length and width of one side of the roof in inches.
If your roof pitch is 3 12 or 4 12 multiply by 1 25.
The answer is the number of square feet of.
There should be no wrinkles or other spots that could catch moisture and cause problems.
Felt underlayment can overlap more than 2 inches to provide an adequate barrier.
Step 6 overlap next roll.
If you have a vertical seam where one piece ends and another starts make the overlap at least 6 inches.
Some roofing felts are actually glued down.
This paper is a new and in some aspects improved material for roofing underlayment.
All nails should be placed at least 12 inches away from the center of the valley.
Make sure the rolls overlap by at least four inches and staple them into place on the wood.
Continue this for each surface of your roof.
