New Bern 1

Framing A Hip Roof

One of the two most popular roof designs, if not the most popular is the hip roof. Not only

does it add architectural lines to the design of a house, but it also offers more protection

from the elements to walls, windows, and doors, when framed with a generous overhang. It

also lends more to the structural integrity of a home with its rafters tying off to all four

corners and walls of the structure.

A hip roof is a little more complex to frame than a gable roof. Besides a ridge board, a

gable roof has only common rafters (all rafters the same length) as its only components. The

components of a hip roof are the ridge board, common rafters, hip rafters, and jack rafters.

The hip roof does not always have a ridge board. If the building is a square with all four

walls being the same length, there will be no ridge and the roof will resemble a pyramid.

When cutting the common, hip and jack rafters, their lengths can be determined by using a

calculator or a rafter table book like “The Full Length Rafter Framer”. the length of the

ridge can be determined by subtracting the width of the building from its length. For

example, if the building is 30 x 24, the ridge will be 6 feet in length. If the ridge board

is 1 1/2″ thick (which is usually the case), then 1 1/2″ needs to be added to the ridge

length. This is because all common rafters are shortened half the thickness of the ridge or

3/4″. This allows the top of the common rafters to line up with the top of the ridge at each

end.

When framing a hip roof, always start with the common rafters. This will place the ridge in

its proper location. This part of the roof is framed like a gable roof, but the similarity

ends there.

Start by nailing common rafters on one side of the ridge at each end. Now raise the ridge

and nail two rafters on the other side of the ridge opposite the first two rafters. Once

this is done, push the ridge up so the birdsmouth cuts pull in tight to the walls on each

side of the building. These rafters can now be nailed to the wall in their corresponding

locations in relation to the ridge. Now nail the two common rafters to the center of the end

walls and to the ends of the ridge board. This will lock the ridge in its exact location.

The rest of the common rafters can be nailed to the wall and ridge board.

The next parts to be installed are the four hip rafters. These are nailed on the outside

corners of the buildings walls and in the intersection made by the end and first common

rafter where they meet at the ridge. With the hips and common rafters in place, its easy to

see why this makes for such a strong and solid roof.

With the hip rafters in place the jack rafters can be installed. Before nailing on the first

jack rafter, a string must be run from the plumb cut on the hip rafter to just above the

birdsmouth. This can be done by driving a nail in the center of the hip at the above mentioned

locations. Tie the string to one nail, pull it tight, and secure it to the other nail. This

is to ensure the hip rafter stays straight during the jack rafter installation. As the jacks

are nailed on, the string should be kept at the center of the hip. To help keep the hip

rafter straight, the jack rafters should be nailed on in pairs, first one side of the hip,

then its mate on the other. This process is continued all the way down the the hip rafter

till all jack rafters are installed on both sides of the hip. Remove the string and repeat

this procedure on the remaining three hip rafters to complete the framing of the roof.

Collar ties and fascia boards will need to be installed before the roof can be sheathed, but

these are the basic steps to framing a hip roof.

commercial roofing