In very hot climates many designers specify a hipped roof since a hipped roof with wide roof overhangs will keep the sun off the windows on all four sides of the house.
Good roof overhang for sunny climates.
Best roof for rainy climate.
Do not undervalue their importance.
For instance i think that in heavy snow country large overhangs can lead to ice dams forming on the overhangs snow melting.
Roof overhangs for summer shade and moisture protection.
In moderate climates there is some damage of wood decay and a roof overhang is recommended.
With fixed overhangs overheating in the fall months may still be a concern because by then the sun is lower in the sky while the outdoor temperatures may still be fairly high.
Roof overhangs provide shade.
The intent of roof venting varies depending on climate but it is the same if you re venting the entire attic or if you re venting only the roof deck.
In a cold climate the primary purpose of ventilation is to maintain a cold roof temperature to avoid ice dams created by melting snow and to vent any moisture that moves from the conditioned.
They are critical to shade windows from undesired solar heat.
In general roof overhangs offer an effective solution for how to protect windows doors and entryways.
And also to protect exterior walls doors and windows from rainwater while keeping the foundation dry.
If the roof overhang is not big enough then the only way to protect these windows doors and entryways is by recessing them into the thick exterior wall or by installing special casing and flashing for each door or entryway.
Cross index the 36 row and the mixed climate column and the recommended values are an overhang depth of 4 0 and a height above the window of 2 8.
Some decades ago along with modern design principles there came the widespread vogue of flat roofs and no roof overhangs.
Metal roofs are extremely durable and can withstand large amounts of rain and wind with minimal need for repair.
South facing windows can effectively be shaded with fixed overhangs because in the summer the sun is much higher in the sky than in the winter when that sunlight is beneficial for heating.
See below i need to acknowledge there are some good reasons in some places to not have a large overhang.
The best roof for rainy climate varies from asphalt shingles slate and or pitched roof.
In very rainy climates where water and moisture can contribute to siding rot deep roof overhangs will protect your exterior walls and foundation.
Here the recommended overhang length can extend up to 12 inches for moderately rainy climates or up to 18 inches for climates that experience more frequent rainfall.
Much of the united states falls into this category especially along the coasts.