The roof dormer is an architectural structure protruding out from a slanting roof. They add structural frames for windows and offer additional living space in your attic. Gable and Hip dormers are most the commonly used architectural styles of dormers.
Gable Roof Dormer
A gable is a triangle formed by the 2 sloping planes of the roof of a building, meeting at the ridge beam in the middle. Gable roof dormers project at a right angle to the roof. In a gabled dormer, the side walls take the load of roof rafters and shift the load on to the rafters in the main roof.
Advantages and Disadvantages of Gable Dormers
Gable dormers have a universal appeal. These are traditional in style, simple in design, easy and inexpensive to construct. The gable design uses the force of gravity for the stability of its elements. They provide extra space for living, by allowing 1/2 story space at the top of your house.
Because of their steep sloping sides, the gable dormers allow easier flow of water down the roof. They can withstand most climates and particularly heavy snowfalls. As the snow slides off easily on the steep slope of the roof, there is no danger to the roof for damage on caving in.
These roofs are suitable for places where there is a ban for storied houses, like in some communities.
A gable roof will also not shade the walls at its gables.
Hip Roof Dormer
In a hipped dormer, the hip roof slopes upward on all 3 sides of its structure. There are no vertical ends. The external angle at which 3 adjacent sloping sides of the roof meet is called a hip. The degree of such a slope is denoted as the hip bevel. There is a triangular sloping surface created by hips, which meets at the ridge of a roof. This is known as a hip end.
A square hipped roof has a single point at the top from where its sides slope down. In the same manner, the rectangular hipped roof makes an edge on top of the projected length. Hip dormers are very sturdy. The hipped dormers are commonly built in ranch homes and cottages.
Advantages and Disadvantages of Hipped Roofs
Hipped roof dormers provide comfort, utility, and sturdiness. It is easier to construct their walls, which are at 1 level and carry the load of the roof. The hip roofs are symmetrical about their middle line. The hip roofs at the top of the house reveal all the sides and present a clean aesthetic look.
As this type of roof has a steady, level fascia, it is easier to fit a gutter all around.
Moreover, there are eaves all round, which also protect the building walls from severe weather conditions, and provide the shade on walls from the sun. You need less energy for cooling the house in warm weather.
A hip roof is much stronger in withstanding the wind pressure in a hurricane, and more suitable for regions of Northern Australia and Gulf Coast in the Southeastern United States, to comply with the strict construction codes.
The disadvantage with the hipped dormers is that they provide less space, because of the slanting plane on their front side.
Hip roof dormers are more complex to construct than a gabled dormer, as they involve more use of more intricate systems of trusses, and thus cost more.