Many codes municipalities and manufacturers require at least a 15 lb.
15 lb felt roof overlap.
The roofing felt should be applied in layers that overlap.
Roofing felt is required to overlap 2 inches over the lower felt course.
Plywood or osb roof deck so 15 20 or 30 will work for any shingle roof the type i recommend depends on roof slope.
This gardner asphalt 15 432 sq.
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.
One roll of conventional 15 felt covers 432 square feet 40 1 m 2.
Purchase enough felt to cover your roof s area.
This underlayment features excellent asphalt saturation for effective waterproofing.
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.
It s available in two thicknesses.
A conventional roll of felt is enough for 432 square feet.
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.
However you must allow for overlaps on joints.
Convert the area from inches to feet prior to purchasing your felt.
Felt underlayment for all roof installations or replacements.
Unrolled length that combine to provide over 430 sq.
At s a roofing we disagree with this statement.
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.
Buy the roof felt.
Fifteen pound felt has a perm rating of about 5 although this number can rise in high humidity conditions.
As you work the paper can be tacked down in the center so it won t blow away.
Therefore a 2 inch overlap provides redundancy at the edges where the barrier is weakest.
For residential and commercial use.
15 asphalt felt roofing underlayment provides an extra layer of protection between your shingles and your roof deck.
Felt has a 36 in.
In most cases this will leave 400 square feet 37 m 2 of net coverage per 1 roll.
Width and a 144 ft.
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.
Product may vary by store.
