A rafter is a structural component that is used as part of a roof construction. Typically, it runs from the ridge or hip of the roof to the wall plate of the external wall. Rafters are generally laid in series, side by side, providing a base to support roof decks, roof coverings and so on.
What does the name rafter mean?
The definition of a rafter is someone who uses a raft, or the boards that support a roof. An example of a rafter is someone who rafts down whitewater rivers. An example of a rafter is the large beam from which you can hang a heavy chandelier. noun. 0.
What rhymes with Rafter?
Words that rhyme with rafter | Words rhyming with rafter. We found the following words that Rhyme with rafter a quarter after after, angle rafter, ask after, aspire after, atafter, auxiliary rafter be after, be sought after, been after, before and after, being after, binding rafter
What is another word for rafter?
noun beam synonyms for rafter Compare Synonyms beam axle balk bolster boom brace cantilever column crossbar crosspiece girder jamb joist lintel pile piling pillar plank pole post prop scantling shaft sill spar stanchion stay stringer strip strut stud timber two-by-four
How to calculate your rafter length?
rafter length = √ (rise² + run²). The formula used to calculate rafter length from roof pitch is, in fact, the same as the one above. The one difference is that we need to calculate the roof rise using the pitch first. So what you need to do first is to get the pitch, using the following formula: rise = run * pitch.
What is a rafter?
Rafters. The rafters are a series of sloped structural pieces that will extend from a ridge area to the plate of a wall and used to support the load of the building and is a structural component of a pitched roof. The rafters are used as part of roof construction and generally laid in series, side by side providing a base to support roof decks, ...
How to Build the Rafters?
The first step to build the rafter is to cut one rafter board to length with the ends angled properly. Then to mark and cut the bird’s mouth and a seat on the rafter and to the angle of the roof slope, the ridge end and often the eve end of the rafter will need to be cut.
How to make rafters from the first rafter?
Make Set of Rafters From The First Rafter: In this step to make two more rafters use the first rafter and place the first rafter on second and third boards and then onto the second board trace the bird’s mouth, seat, and ridge angles. Cut the second and third rafters out and prepare them.
How far should rafters be overhanging?
At the ridge, the rafter ridges should be fully touching each other along the cuts, and along with the entire cuts, the seats should be flush with the edge of the shed floor. By one-half of an inch, each rafter should be overhanging the edge of the shed floor.
Where does the rafter run up to the hip rafter?
This sits on the outside walls and with the common rafters run up to the hip rafter in line.
Why is less advanced planning needed for rafters?
Less advanced planning is needed because rafters are stick-built on-site at the time of need.
Where do rafters run?
A common rafter is found in all conventionally framed roofs and run from an exterior wall all the way up to the ridge board and used to set the center the ridge board in the span and height.
What is a rafter reinforced with?
A rafter can be reinforced with a strut, principal purlin, collar beam, or, rarely, an auxiliary rafter (see below). Rafter types include: Principal rafter (major rafter, rarely a chief rafter): A larger rafter. Usually land directly on a tie beam. Usually the purpose of having a larger rafter is to carry a purlin which supports ...
Why do people use trussed rafters?
In recent buildings there is a preference for trussed rafters on the grounds of cost, economy of materials, off-site manufacture, and ease of construction, as well as design considerations including span limitations and roof loads (weight from above).
What is a binding rafter?
A "binding rafter" is not a rafter but an obsolete name for a purlin or support. Part of a cruck frame may function as a rafter but they are called a cruck blade. Rafters are usually made of pine or cedar.
What is the piece added at the foot to create an overhang or change the roof pitch called?
A piece added at the foot to create an overhang or change the roof pitch is called a sprocket, or coyau in French. The projecting piece on the gable of a building forming an overhang is called a lookout. A rafter can be reinforced with a strut, principal purlin, collar beam, or, rarely, an auxiliary rafter (see below).
What is a coyau rafter?
A rafter is one of a series of sloped structural members such as wooden beams that extend from the ridge or hip to the wall plate, downslope perimeter or eave, and that are designed to support the roof shingles, roof deck and its associated loads. A pair of rafters is called a couple.
How long is a LVL rafter?
For longer span rafters, building materials manufacturers have created LVL ( Laminated veneer lumber) rafters that can be 2–5 times longer than typical wood rafter. In US, most wood rafters have maximum length of 20 feet. If a longer rafter is needed, LVL is the ideal combination alternative.
What is a rafter on a hip roof called?
Hip rafter (angle rafter): The rafter in the corners of a hip roof. The foot of a hip rafter lands on a dragon beam. King rafter: the longest rafter on the side of a hip roof in line with the ridge. Valley rafter (historically also called a sleeper): A rafter forming a valley (look for illustration showing a valley).
What is a rafter in construction?
In the field of construction, rafters are a series of sloped structural pieces that will extend from a ridge area to the plate of a wall or an eave. They are used to support the load of the building, especially the roof area.
Why do people use rafters in their attic?
When a person chooses rafters for their construction project, they are guaranteeing that they will have more room in their attic. This is excellent for those who want to use this space for more than storage. The rafters will allow an owner to create an extra room in the attic, whether it is a home office, bedroom, work out room, playroom, ...
What is a principal rafter?
Principal Rafter – The principal rafter is always going to be one of the larger rafters and they always get placed on a tie beam. There are times when you will hear the top portion of a truss called a principal rafter, because that is what it looks like. Common Rafter – This type of rafter is slightly smaller than a principal rafter, ...
Why do rafters cost more to build?
It also costs more to make them, mostly because of all the on-site time that is required. It is also necessary for those constructing the rafters to be skilled employees that have been trained at how to build them properly. After all, one minor mistake can cause major issues later one.
What is a rafter in an attic?
The rafters will allow an owner to create an extra room in the attic, whether it is a home office, bedroom, work out room, playroom, or simply a large empty space that can be used for multiple things. Rafters will also allow people to choose different ceiling options, because there is enough attic space available.
What is an auxiliary rafter?
Auxiliary Rafter – An auxiliary rafter is considered a secondary rafter and it supports the principal that is located above it. This type of rafter is rare, but you will also hear it called cushon, compound, or sub rafter. Compass Rafter – A compass rafter is curved or bowed at the top or on both the top and the bottom.
Why do people insulate their attics?
Everyone is trying to be more energy efficient nowadays, which is why more people are choosing to insulate their attics. When a person installs raf ters, they will have no problems at all installing insulation up in the attic. It will also be possible for them to install a radiant barrier or anything else that they think will assist them in saving energy. The installation process is very straightforward and takes less time than it would if a person had something other than rafters up in their attic.
Why do builders use rafters?
Small Projects: Many builders choose rafters for sheds, small additions, or cabins to save the hassle of ordering and waiting on trusses.
What is a rafter roof?
Rafters are the traditional means of framing a roof. Building a roof frame with rafters is known as stick framing. This means that each rafter is built on the job site using dimensional lumber. Every piece is measured, cut, and fastened together to form the rafter. The stick framing process is labor-intensive.
What Is a Roof Truss?
One good roof truss definition is, “a prefabricated wooden structure that integrates a triangular webbing of structural members to provide support for the roof above while tying the outside walls of the house together.”
How long is a truss span?
Truss spans can reach up to 60 feet. According to the American Wood Council, the maximum span for rafters is about 30 feet, and that’s with a relatively low load of 20lbs per square foot. As the load goes up for snow in northern climates or for heavy roofing material like tile, the span length decreases.
Which is better, trusses or rafters?
In a nutshell, trusses are right for most projects. Rafters are a better choice for specialty projects.
How long does it take to build a rafter?
On the same home, rafters might take a week to build, depending on the size of the crew. This slows the overall pace of the project, and the framing is susceptible to weather exposure for much longer.
Where are rafter boards fastened?
Rafter boards are fastened to the ridge board at the peak and the top plate where they join the wall. In finished space, insulation is placed between the rafter boards and drywall, or other material is fastened to the face of the boards. Ridge Board: The ridge board must be the same width as the rafter boards.
What is Attic Rafter Ventilation?
Attics being the bigger part of your home require enough ventilation besides insulation. Attics need to be free from clogs to ensure maximum airflow. Due to the accumulation of debris, the vents become clogged. For this, there have to be certain measures taken and procedures to follow.
Are Rafter Vents And Baffles Same?
You call it rafter vents or baffles, both are the same. Baffles are also known as venting chutes, rafter vents and even wind baffles. Generally relating to the field of the roof and attic ventilation systems, this came to be referred to as baffle vents, venting channels or under-roof-deck vents or attic insulation vents.
What is a rafter vent?
Rafter vents, often called baffles protect intake vents in your attic from becoming clogged or covered by insulation or debris. Rafter vents ensure the soffit vents are clear and there is a channel for outside air to move into the attic at the soffits and out through roof vents.
Do rafters need baffles?
Keep in mind not all rafter need baffles, just those with intake vents at the soffit. If you don’t have baffles installed, check your intake vents for any type of blockage from insulation or debris. This can be cumbersome since you will need to squeeze to the corners of your attic.
Can you install soffit vents in Chicago?
Here in the Chicago metro area, this is far too common. The good news is, soffit vents can be installed and are not very expensive. Depending on the size of your home, the job can be done in a few hours with the right tools and experience.
What is a rafter run?
Definition of rafter run: the horizontal or level distance covered by the rafter - the bottom chord or base of a right triangle. In our sketch above the rafter run is shown as RUN under the left half of the roof.
What is a common rafter?
Definition of Common Rafter: shown in red in our sketch, a common rafter runs at right angles to (90°) to the building front and back walls, as seen when looking down from above. A common rafter runs from the roof ridge to the top of the front or rear wall plate, and extend beyond the wall to provide an overhang or eaves or soffit.
What is a cripple jack rafter?
Definition of Cripple Jack Rafter or Valley Jack Rafter: a rafter running at right angles (90°) from the ridge of a roof down to the valley below. Cripple jack rafters or valley jack rafters never make it to a wall top plate - instead they intersect a valley formed by another roof.
What is Valley Rafter?
Definition of Valley Rafter or cripple jack rafter: a rafter extending from the roof ridge down to the top plate of a wall at the intersection of a gable extension roof that itself abuts or intersects with the main roof.
What is a hip rafter?
Definition of Hip Rafter: a rafter that runs diagonally between the roof ridge and the top of the wall plate, forming a hipped roof.
How many ocs are required for rafter ties?
Building codes such as the ICC's 2012 International Building Code section 2308.10, Roof and Ceiling Framing typically specify that where rafter ties are used, they are required at intervals ranging from 12" to 24" o.c. depending on the roof design and the roof rafter spacing. Where rafter ties are not being installed with every rafter pair, model codes often specify that
Why does my roof truss sag?
It is because the bottom chord of a roof truss is in tension that the truss member can be as small as a 2x4. However the weight of a ceiling affixed to rafter ties of any dimension can cause ceiling sagging unless the lumber is also sized to support the vertical load or weight of the ceiling.
What is a rafter tie?
Rafter ties prevent spreading. Located in the bottom third of the roof structure, rafter ties effectively resist the horizontal forces caused by gravity loads that would otherwise cause the roof to pancake, pushing the sidewalls out.
Do collar ties help with uplift?
Collar ties prevent uplift. Contrary to popular belief, collar ties are not there to support rafters or to keep walls below from spreading under the weight of the roof. That’s the job of the rafter ties or the ceiling joists. If you’re not sure if you need collar ties, you should consult an engineer.
Do you need rafter ties for cathedral ceiling?
Rafter ties (or ceiling joists acting as rafter ties) are required by code unless the house is designed so that the walls or a structural ridge beam carries the full load of the roof. If you are framing a cathedral ceiling, there are a couple ways to deal with the need for rafter ties.
