Usually 4/12, it will say on the bundle of shingles. At that pitch you would probably want a layer of bituminus underlayment under the shingles, at least anywhere where it is cold in winter.
The type of shingle you need really is a factor of what slope your existing roof has. A low slope roof needs a much different type shingle than a high slope, as water can intrude under the low slope. In this situation, a different type roof might be a better option.
26 square feet? That is not a roof that is a patch. 5' X5' is 25 square feet, so a minimun job call for a roofer, about $100
Refer to Fastest Shingle Roofer answer
We were looking at shingle samples for our new roof.
A shingle...
Depends on the type of roof and type of shingles used.
That depends. If this is a shingle or "steep slope" roof system, one layer of felt lapped 4" would be sufficient. A typical roll of #30 felt covers 200 sf.
It really depends on the size of the roof and how long you have to work on it.
Nope
A leaking roof can be a headache for many owners. In addition, a leaking roof can cause extensive water damage inside a home, potentially damaging the foundation. A shingle roof is simple to repair. Locate the damaged shingle on a rooftop, and pull back the shingles above it. Using a claw hammer, remove the nails holding in the damaged shingle. Check for any existing damage to the tar cover. If there is any damage, repair it with silicone or roofing tar. Place the new shingle under the existing roof shingles, and nail in place. Make sure no other shingles were dislodged.
Composition roof lifeAsphalt shingles are rated at 20, 25, 30, or 35 years. The average roof life is 5 to 10 years less, depending on climate conditions in your area. The life of any asphalt shingle roof is effected if Algae and Mildew is allowed to grow on it. The plant wraps it''s roots around the granules on your asphalt shingle roof, and as it grows, it can actually force the granules to come loose. Proper non pressure roof cleaning will extend the life of any shingle roof with black streaks or mildew growing on it "
A thin piece of wood that covers a roof is called a shingle.