A timber pitched roof is a type of roof that has an angle of inclination exceeding about 10° with the horizontal. It is commonly used in hilly areas and in regions where extreme winds, rains, and snowfalls are experienced. Pitched roofs can have slopes on both sides or they may be sloping in one direction only. The angle of slope is increased in proportion to the severity of weather conditions.
Pitched roofs are constructed using various materials such as timber, structural steel, reinforced concrete (RCC), and prestressed concrete. These materials provide strength and stability to the roof structure.
Terms Used in Pitched Roof
When it comes to timber pitched roof construction, it’s important to understand the various technical terms associated with it. These terms help professionals communicate effectively and ensure that the construction process runs smoothly. In this article, we will explore technical terms used in timber pitched roof construction.
The span refers to the horizontal distance between the supporting walls or beams of a roof. It determines the overall width of the roof and affects the load-bearing capacity of the structure. Properly calculating the span is crucial for ensuring the roof’s stability and durability.
2. Rise of Roof
The rise of the roof is the vertical distance between the top of the wall plate and the highest point of the roof. It determines the steepness of the roof and affects its overall appearance. The rise of the roof is an important factor in determining the pitch.
3. Pitch of Roof
The pitch of the roof refers to the slope or steepness of the roof. It is expressed as a ratio of the rise to the span. For example, a roof with a 1:4 pitch means that for every 4 units of horizontal distance, the roof rises by 1 unit. The pitch of the roof affects its drainage capabilities and resistance to weather elements.
The eaves are the lower edges of the roof that overhang the walls. They provide protection from rainwater and direct it away from the walls and foundation. The eaves also play a role in enhancing the aesthetic appeal of the roof.
The ridge is the horizontal line where two roof slopes meet at the highest point of the roof. It forms the apex of the roof and is often reinforced to provide additional structural support.
6. Ridge Piece
The ridge piece is a horizontal timber member that runs along the ridge of the roof. It provides a base for attaching roof coverings and helps distribute the weight of the roof evenly.
7. Ridge Beam
The ridge beam is a load-bearing timber or steel member that supports the weight of the roof and transfers it to the supporting walls or columns. It is typically larger and stronger than the ridge piece.
8. Ridge Board
The ridge board is a non-load-bearing timber member that connects the rafters at the ridge. It helps to stabilize the roof structure and provides a surface for attaching roof coverings.
A valley is the internal angle formed by the intersection of two roof slopes. It directs rainwater towards the eaves and prevents water from pooling on the roof surface.
A hip is an external angle formed by the intersection of two roof slopes that are inclined inwards. Hips are commonly found in roofs with multiple slopes and add architectural interest to the structure.
11. Hipped End
The hipped end refers to the sloping end of a roof that is formed by the intersection of two adjacent roof surfaces. This design is commonly used in houses with a more complex roof structure.
A gable is the triangular portion of a wall between the edges of intersecting roof pitches. It is typically found at the end of a pitched roof and adds aesthetic appeal to the overall design.
The verge is the edge of a pitched roof that extends beyond the external wall. It provides protection to the underlying structure and helps to prevent water from seeping into the building.
14. Barge Board
A barge board is a decorative board that is fixed to the projecting edge of a gable roof. It not only enhances the visual appearance of the roof but also provides additional protection.
15. Eaves Board
The eaves board is the horizontal board that runs along the edge of the roof, overhanging the walls of the building. It helps to channel rainwater away from the walls and foundation, protecting them from water damage.
16. Fascia Board
A fascia board is a vertical board that is fixed to the ends of the rafters, just below the edge of the roof. It provides support to the lower edge of the roof tiles and acts as a finishing trim.
17. Common Rafters
Common rafters are the sloping beams that support the roof covering. They are typically evenly spaced and run from the ridge to the eaves, providing structural stability to the roof.
Purlins are horizontal beams that support the common rafters. They are placed parallel to the ridge and help to distribute the weight of the roof covering evenly.
Cleats are metal brackets or straps that are used to secure the purlins to the rafters. They provide additional strength and stability to the roof structure.
20. Wall Plates
Wall plates are horizontal timbers that are fixed to the top of the walls to support the roof structure. They provide a secure base for the rafters and help to distribute the weight of the roof evenly.
A template is a pattern or guide used in roof construction to ensure accuracy and consistency. It is typically made of wood or metal and serves as a template for cutting and shaping various roof components.
22. Hip Rafters
Hip rafters are inclined beams that run diagonally from the corners of a roof to a ridge. They are used to support the ends of the roof and provide stability.
23. Jack Rafters
Jack rafters are shorter rafters that run from the ridge to the eaves. They are placed between the hip rafters and provide additional support to the roof structure.
24. Valley Rafters
Valley rafters are rafters that run along the internal angle formed by two intersecting roof slopes. They are used to channel water away from the roof and prevent leaks.
25. Post Plate
A post plate is a horizontal timber beam that sits on top of the wall and provides support for the roof structure. It is typically bolted or nailed to the wall.
Battens are thin strips of wood or metal that are fixed to the rafters or roof deck. They provide support for the roofing material and help create a level surface for installation.
Boarding refers to the wooden or metal sheets that are fixed to the rafters or battens. It forms the base for the roof covering, such as tiles or shingles.
Features of Pitched Roofs
Pitched roofs have several distinct features that make them a popular choice for many homeowners and architects:
The most prominent feature of a pitched roof is its slope. The slope allows rainwater and snow to easily slide off the roof, preventing water accumulation and potential damage.
Pitched roofs can be constructed using various materials such as tiles, shingles, metal sheets, or thatch. The choice of material depends on factors like climate, budget, and desired aesthetics.
3. Attic Space
Pitched roofs often create additional attic space, which can be utilized for storage or even converted into living areas.
Benefits of Pitched Roofs
Pitched roofs offer several advantages over other types of roofs:
1. Weather Resistance
The slope of a pitched roof allows rainwater to easily drain off, reducing the risk of leaks and water damage.
Pitched roofs are known for their durability and longevity. When properly maintained, they can last for several decades.
3. Aesthetic Appeal
The unique shape and design of pitched roofs add a touch of elegance and charm to any building, making it visually appealing.
4. Increased Property Value
A well-maintained pitched roof can significantly enhance the value of a property, making it a wise investment.
Considerations for Pitched Roofs
Before opting for a pitched roof, there are a few considerations to keep in mind:
Pitched roofs tend to be more expensive than flat roofs due to the additional materials and labor required for installation.
While pitched roofs are generally low-maintenance, periodic inspections and repairs may be necessary to ensure their longevity.
3. Architectural Compatibility
The design and pitch of the roof should be compatible with the overall architectural style of the building.
Materials Used for Pitched Roofs
There are various materials that can be used for constructing pitched roofs:
1. Roof Tiles
Clay or concrete roof tiles are a popular choice for pitched roofs. They are durable, aesthetically pleasing, and come in a variety of colors and styles.
Asphalt or wooden shingles are commonly used for pitched roofs. They provide a rustic look and are relatively easy to install.
Metal roofing materials, such as steel or aluminum, are lightweight, durable, and require minimal maintenance. They are often used in modern and industrial-style buildings.
Slate is a natural stone material that is known for its durability and longevity. It is commonly used in high-end residential and commercial buildings.
Maintaining a Pitched Roof
To ensure the longevity and performance of a pitched roof, regular maintenance is essential:
1. Inspect the Roof
Regularly inspect the roof for any signs of damage, such as cracked tiles or loose shingles. Address any issues promptly to prevent further damage.
2. Clean Gutters and Drains
Clear out debris from gutters and drains to prevent water from pooling on the roof.
3. Trim Overhanging Branches
Trim any overhanging branches that could potentially damage the roof during storms or high winds.
4. Remove Moss and Algae
If moss or algae growth is present on the roof, remove it carefully to prevent damage to the roof material.
Understanding these technical terms is essential for anyone involved in timber pitched roof construction. Whether you’re a homeowner planning a roof renovation or a professional builder, having a clear understanding of these terms will help you communicate effectively and ensure the success of your roofing project.