You might hear some say if the felt paper is nailed then it basically is ruined or is not applicable as a water proofing agent.
15 lb felt roof overlap.
This underlayment features excellent asphalt saturation for effective waterproofing.
At s a roofing we disagree with this statement.
Felt has a 36 in.
Unrolled length that combine to provide over 430 sq.
The overlapping felt creates a secondary barrier for moisture and wicks water away from the shingles above and the sheathing below.
Since you will have overlap between rows this works out to a total coverage area of 400 square feet the dimensions of a 20 x 20 roof.
Convert the area from inches to feet prior to purchasing your felt.
For residential and commercial use.
Therefore a 2 inch overlap provides redundancy at the edges where the barrier is weakest.
The roofing felt should be applied in layers that overlap.
In my opinion felt paper is a vapor barrier plus keeps the oils in the shingles from leaching out and into the wood substrate i e.
Product may vary by store.
One roll of conventional 15 felt covers 432 square feet 40 1 m 2.
However you must allow for overlaps on joints.
A conventional roll of felt is enough for 432 square feet.
Fifteen pound felt has a perm rating of about 5 although this number can rise in high humidity conditions.
In most cases this will leave 400 square feet 37 m 2 of net coverage per 1 roll.
It s available in two thicknesses.
Width and a 144 ft.
Buy the roof felt.
Plywood or osb roof deck so 15 20 or 30 will work for any shingle roof the type i recommend depends on roof slope.
15 felt type construction helps provide an extra layer of protection between your shingles and your roof deck not included heavy duty design lays flat to help minimize wrinkling asphalt saturation to help improve waterproofing ability to help prevent wind driven rain and water from other sources from infiltrating under your shingles and.
Start at the bottom of the roofline and work up so any water that gets through the roofing material will shed down the tar paper and will not go under it.
Felt underlayment for all roof installations or replacements.
Of coverage for residential and commercial roofing projects.
Roofing felt is required to overlap 2 inches over the lower felt course.
As you work the paper can be tacked down in the center so it won t blow away.
15 asphalt felt roofing underlayment provides an extra layer of protection between your shingles and your roof deck.
Many codes municipalities and manufacturers require at least a 15 lb.
