Roof styles are many and varied. You have a ton of choices here in designing your new home. Not only the roof style, but all the other details including roof pitch, overhang details, and of course roofing materials. In all likelihood, the roof framing of your new home will either be "stick built", roof trusses, or a combination of the two.
Basic Roof Styles
Roof trusses are those roof shaped frames that you've seen stacked at construction sites.
Trusses are engineered and shop built for each job.
Roof truss design is done by engineers, specializing in this area of expertise.
If your construction will be subject to inspections by a local building official, they will want to see the stamped truss plans before construction begins.
Trusses are designed to concentrate the entire roof load at the ends of the truss.
This means that the trusses actually span the distance between their two end bearing points.
Although there may be walls under the trusses, they are "partition" (non-load bearing) walls. The advantages of using trusses are cost and speed and ease of installation.
Trusses can be constructed to accommodate almost any roof configuration, but in a practical sense, the simpler the roof,
the more attractive trusses are to use. They are ideal for straight runs of a gable roof.
The disadvantage of using trusses is that the webbing required to create the strength of the truss takes up a lot of space. When you go up into a trussed space, it's like running into a spider web every two feet. There's not much usable storage space.
Are trusses as good as an old fashion, conventionally framed roof? Many people think not. We think so. Trusses have proved to be just as sound structurally as the old system. In some cases, even more so. It's hard to screw up a truss system unless your carpenter starts cutting them up!
Stick Built Roof
The alternative to using trussed in framing a roof is to "stick build" the roof - which is exactly what it sounds like. All of the roof members are cut and installed on the site.
The photo (right) shows you some of the members involved in a stick built roof. One advantage is the additional storage space you'll have in the attic.
A disadvantage may be a more complicated load carrying system throughout the house.
With the other structural elements you're pretty well stuck. Walls go straight up and down. Floors and ceilings are flat.
But most roofs slope! And you get to decide how much. The slope is expressed as so many inches rise (or fall) in 12 horizontal inches (see "Truss Parts", above). A "12/12" pitched roof is sloped at a 45º angle.
A 5/12 to 7/12 pitch is pretty typical in most parts of the country. In warm climates like the desert southwest and Florida, lower slopes are common. Up north steeper pitches are used to help shed snow loads.
The higher the pitch, the more roof surface you'll have, and the more sheathing, paper, and roofing you'll need. Also, roofers charge more for steep roofs because they're harder to work on. You may want to find out at which pitch they start to raise prices in your area.
Just look at these roof styles and check out the range of roof pitches.
Flat roof construction is unusual in single family construction - unless you're doing a southwest adobe stucco like this one. The biggest difficulty is avoiding leaks.
Other Parts Roof Framing
Here are some other things that, although they are not structural are presented here because they are attached to the roof.
This part of the roof (which is often called the cornice) is used to shade the home and to get the water that drains off the roof not to run right down the side of the home.
With improved insulating materials, solar screening materials for windows, and gutter systems, the overhang is mostly decorative.
It also provides a shadow line that is architecturally pleasing.
The parts of the overhang are:
The fascia is the vertical board that drops down at the edge of the roof. It is attached to the ends of the roof rafters or trusses. It is the surface on which the gutters are attached. The fascia is often made of a 1x6 or 1x8. It can also be made of aluminum or vinyl.
The soffit is the horizontal section that runs from the fascia back to the wall of the house. This is where you will often find some eave vents.
is the overhang that occurs at the gable end of the roof. It also consists of a fascia and a soffit.
There is usually a piece of trim on the rake fascia just under the roofing material. This could be shingle mould or simply a piece of 1x2.
Sometimes the rake is omitted. That is, there is no overhang on the gable end. In this case, the rake is usually replaced by a 1x placed flat on the gable end and running just below the roofing.
Dormers are the little roofed projections protruding from a roof which provide an opportunity to get some window space into a room which is tucked up under the roof.
Sometimes they are added for looks, even though there is no room!
is a little pitched roof which is built behind a chimney to shed the water away from the junction of the chimney and the roof - a vulnerable spot
For additional information on house foundations,
see Lesson Five and Lesson Fifteen of our online course
Successful Home Contracting
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