In very rainy climates where water and moisture can contribute to siding rot deep roof overhangs will protect your exterior walls and foundation.
Good roof overhang for sunny climates.
The best roof for rainy climate varies from asphalt shingles slate and or pitched roof.
Overhangs are a key part of any home s design.
In moderate climates there is some damage of wood decay and a roof overhang is recommended.
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.
In general roof overhangs offer an effective solution for how to protect windows doors and entryways.
For instance i think that in heavy snow country large overhangs can lead to ice dams forming on the overhangs snow melting.
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.
They are critical to shade windows from undesired solar heat.
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.
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.
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.
Roof overhangs for summer shade and moisture protection.
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.
See below i need to acknowledge there are some good reasons in some places to not have a large overhang.
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.
Some decades ago along with modern design principles there came the widespread vogue of flat roofs and no roof overhangs.
Best roof for rainy climate.
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.
These kinds of roofs are rampant across the northern part of the us largely due to their ability to withstand cold climate elements like wind snow and heavy rain.
If durability is your primary goal a metal roof made from either steel or aluminum is an excellent option for your roof.
Roof overhangs provide shade.
Do not undervalue their importance.