Cornice Cornices are usually made from stone or brick, but they can also be made out of other materials such as wood, metal and even concrete. Cornices are used to protect the front of a building from being damaged by rain, wind and snow. They can also serve as decorative elements when there is no need for protection against weather. Cornices are often found at the top of buildings, especially tall ones. Cornice images can vary greatly depending on what type of building it is and how it was built. For example, a large church will usually have much bigger and wider cornices than a small house. Without a proper cornice, buildings may suffer from water damage and even collapse in extreme cases. For example, a stone cornice would look very different from a wooden cornice. In the case of a stone cornice, it would probably look like the one in the picture to your right. In the case of a wooden cornice, it could be anything from a simple box cornice to an elaborate Victorian style cornice.
Types of Cornice Roofs The most obvious function of a cornice is to keep out the elements, but they also have several other purposes, some of which are decorative. It is important to keep in mind that different types of cornice roofs serve different purposes. The most common types of cornice roofs are the box cornice, cavetto cornice and modillion cornice. 1.
Box Cornice A box cornice is one that is flat at the top. It is also known as a simple cornice. The keystone in an arch is also known as a box cornice. This type of cornice is the simplest and the easiest to construct. The pictures to your left and above show good examples of box cornices. 2. Cavetto Cornice Also known as an undulating cornice, this type of cornice has a concave moulding and is often used above archways and around doors. In the picture to your right you can see a good example of a cavetto cornice. 3. Modillion Cornice A modillion cornice has one or more vertical supports called modilloms. This type of cornice is often used in association with other types of cornice to provide additional support. In the picture to your left you can see an example of a modillion cornice.
Other Types of Cornice 1. Open Cornice An open cornice is one without a framework that supports the roofing material. 2. Closed Cornice A closed cornice is one that has a solid framework all the way around it.
Cornice Roofs vs Soffits While cornices are decorative, soffits are not. A soffit is the underside of any overhanging structure such as a roof. Cornice roofs can be made of wood, brick, stone, metal or any other appropriate material. In the picture to your right you can see a good example of a soffit.
Where is the Cornice on a House? The cornice is the top part of a wall, just beneath the roof. It is usually made from wood, metal, plastic or stone and it is designed to protect the wall from water damage caused by rain or snow. The picture below shows a good example of a cornice on the top of a house. The purpose of the cornice is to keep water from dripping down the walls.
On a house, the roof is usually supported by the walls, so water would collect around the top of the walls and eventually drip down.
How to Build a Cornice: An Example 1. Choose Construction Type and Material One of the first things you need to do is choose a material to build the cornice out of. You can build a wooden cornice, a metal cornice, a plastic cornice or any other material as long as it can resist water damage. 2.
Measure Cornice Measure the width and length of the wall that will be covered by the cornice. Add 2 inches to both measurements and cut four pieces of molding at these dimensions. 3. Attach Molding to Wall The best way to attach molding around the top of a wall is to use finishing nails. Nail two of the pieces at the top and bottom of the wall, making sure there is a 1/4 inch gap between the molding pieces. Nail the remaining two pieces on the sides. 4. Fill Gaps Between Molding Pieces If there are any gaps between the molding pieces, use wood filler to seal them.
Other Types of Roofs There are many different types of roofs that are used to cover all types of houses and buildings. Here are some of the more common types. 1. Gabled Roof A gabled roof is shaped like the roof of a house, with two sloping sides that meet at the top.
A gable roof is one of the more basic types of roof. You can tell it’s a gable roof if it looks like the picture to your left.
2. Cross Gable Roof A cross gable roof has two different roofs, one sitting on top of the other. The lower roof may point in a different direction than the upper roof creating four different sides. 3.
Skillion Roof A skillion roof slopes on a single axis. A skillion roof is different from a flat roof in that it has a pitch. 4. Shed Roof A shed roof is similar to a gable roof except that it has only one sloping side, rather than two. It is also called a lean-to roof. 5. Curved Roof A curved roof has a circular or curved shape. It may be shallow or steep. 6. Dome Roof A roof that has a curved surface and is relatively shallow is called a dome roof. Like a barrel or sphere, a roof like this is called a hemisphere.
The Different Types of Roof Framing 1. Rafters A rafter is a structural support for a roof. A roof usually has two sets of rafters running parallel to each other and attached at the top of the walls. 2.
Ridge Beam A ridge beam, also called a tie beam or collar beam, is a long and wide piece of wood that supports the ridge of the roof. 3. Jack Rafters A jack rafter is a shorter rafter that is under a slope or an angle of less than 45 degrees. 4. Common Rafters A rafter that is under a roof that makes an angle greater than 45 degrees is called a common rafter. 5. Valley Rafters A valley rafter is a rafter that supports the ridge of a roof on each side of a valley or hollow. A valley rafter is shorter than a jack rafter.
How to Build A Gable Roof 1. Prepare the Wall Studs Measure and mark the top of each wall at the peak of the roof. Using a speed square, draw a guideline from one mark to the other. This will be the location for the ridge beam.
2. Install the Ridge Beam Measure, cut, and install the ridge beam between the peak marks. 3. Framing the Gable Ends Using a carpentry square, draw a line down the middle of the peak. At the bottom of the peak, measure up and mark the length of the rafter you’ll need. This will be the bottom of your gable end. 4. Framing the Gable Ends Using a framing square, extend the sides of the peak up to the outside of the walls. Measure, mark, and cut 2x4s for the side rafters. Using a rafter square, make sure the angle is at 72 degrees. Measure, mark, and cut 2x4s for the neck rafter. Using a rafter square, make sure the angle is at 37 1/2 degrees. 5. Framing the Gable Ends Mark and cut a 2×4 the same length as your neck rafter. Nail it between your side rafters, flush with the top of the side rafters. 6. Framing the Gable Ends Toenail (nail at an angle) your neck rafter to the top of the side rafters. Use a framing square to make sure it’s at the correct angle. 7. Framing the Gable Ends Install a couple of braces to the top of your side rafters and the ridge beam. Nail the braces to the side of the ridge beam, not the top or bottom. This will help transfer the weight of the roof onto the wall studs. 8. Building the Gable Ends Using a belt or post sander, round the peak of your gable ends. You can also use a jigsaw and hand tools. 9. Building the Gable Ends Install your window and door. 10. Build the Soffit Cut 2x4s so they fit tightly between the top of the side walls and the bottom of the rafters. Nail plywood to the 2x4s. The underside of the soffit should be 1 foot in from the edge of the side walls. 11. Build the Soffit On the underside of the soffit, cut 2×4 cleats and nail them perpendicular to the soffit. The tops of these cleats should be even with the side walls. 12. Build the Soffit Install your roofing and shingles. 13. Build the Ridge Beam Build a 2×6 and cut it to length. Install a 2×4 that’s even with the top of the side walls. Nail the ridge beam into place.
How to Build a Gable Roof Framing Diagram
Framing a gable roof is not very difficult. If you’ve framed common roofs before, this will look very familiar. The only difficult part is building the gable ends. You can get by without building them, but your roof will need extra support when it’s time to lay the shingles.
Framing the Gable Ends
If you’re going to build your gable ends then you’ll need to frame the gable ends before you start framing the roof. Start by building your window and door frames. Nail 2×4 cripples to the sides of each frame to hold them in place. Then, measure the height and width of your window and door openings.
Cut 2x4s to fit between the door and window frames and the top of the wall studs. Nail these boards into place. You will have to notch out a little bit of the top of the cripple on the sides so that your 2x4s will fit. After your gable ends are framed, cut and install the rafters. Make sure the tops of the rafters are level. Also, make sure they extend at least 1 foot past the side wall studs. If you’re not going to build the gable ends, you can lay your roofing immediately after installing the ridge beam. If you are, then continue on.
Framing the Gable Ends with Gable Fill
Start by cutting 2x4s so that they fit between the top of the cleats and the underside of your rafters. Nail these 2x4s into place. Cut and install the other rafters so that they fit between the bottom of these 2x4s and the top of the side wall studs. Make sure the tops of all your rafters are level.
You’re pretty much finished with the frame of your roof at this point.
Sources & references used in this article:
- The conservation of a textile covered bed cornice from Harewood House (M Brooks – Conservation of furnishing textiles: post-prints of the …, 1990 – bcin.ca)
- House cornice (PT Frentzen – US Patent 1,668,957, 1928 – Google Patents)
- Cornice-protector. (T Johnston – US Patent 874,510, 1907 – Google Patents)
- Load sharing and structural response of roof–wall system in a timber-framed house (MM Brooks – Text, 2000)
- The Commodus monument from house H21c in Marina el-Alamein (N Satheeskumar, DJ Henderson, JD Ginger… – Engineering …, 2016 – Elsevier)
- Folding summer-house (R Czerner, S Medeksza – 2010 – ceeol.com)