Roofs Flashcards
What are the primary categories of residential roofs?
Residential roofs fall into two main categories: 1. Pitched Roofs: Feature a sloped design to shed water efficiently. 2. Flat Roofs: Have a minimal slope relying on waterproof membranes and drainage systems.
What are the key components of a pitched roof system?
- Ridge: The horizontal peak where two roof planes meet. 2. Valley: Intersection where two sloping planes meet channeling water. 3. Rafters: Sloping structural beams supporting roof decking. 4. Decking: Base layer providing surface for roofing materials. 5. Underlayment: Protective layer beneath shingles or tiles. 6. Gutters: Channels water away from the roof edge.
“What are the essential layers of a flat roof system and what is their proper installation sequence?”
A flat roof system consists of the following layers from bottom to top:
- Roof Deck: Structural base layer providing foundation
- Vapor Barrier: Prevents moisture migration
- Insulation Layer: Provides thermal protection
- Drainage Layer: Helps direct water to scuppers or drains
- Waterproof Membrane: Primary barrier against water intrusion
- Surface Layer (e.g., gravel or reflective coating): Protects membrane from UV and mechanical damage.
Proper installation sequence is critical as each layer supports drainage and water resistance, particularly important for flat roofs prone to pooling.
What materials are commonly used for pitched roof coverings?
- Asphalt Shingles: Affordable, lightweight, and easy to replace. 2. Clay Tiles: Durable, fire-resistant, and common in Mediterranean-style homes. 3. Concrete Tiles: Heavier but offer similar aesthetics to clay with greater affordability. 4. Metal Panels: Lightweight, long-lasting, and energy-efficient.
What is a roof parapet and on which type of roof is it commonly found?
A parapet is a low protective wall that extends above the roofline, typically found on flat roofs. It provides structural support for the roof edge and helps with wind resistance.
What is the function of roof valleys and how does flashing protect these areas?
Roof valleys are V-shaped intersections where two sloping planes meet, channeling water runoff to gutters or drains. Flashing is installed in valleys to guide water down the slope and prevent seepage.
What is roofing underlayment and what role does it play in water management?
Roofing underlayment is a protective layer installed between the roof deck and the outer roofing material, providing an additional barrier against water intrusion.
Define ‘scuppers’ and their function on flat roofs.
Scuppers are openings along the edges of flat roofs that allow water to drain off the roof and away from the building.
What is a roof ridge vent and why is it important?
A roof ridge vent is a ventilation system installed along the peak of a pitched roof, allowing hot humid air to escape from the attic. The roof ridge requires proper integration to handle both water and ventilation: 1. Ridge Cap Shingles. 2. Ridge Vent. 3. Underlayment Overlap.
What is drip edge flashing and where is it installed?
Drip edge flashing is a metal strip installed along roof edges to guide water away from the fascia and into the gutters.
What is torch-on roofing and where is it commonly used?
Torch-on roofing is a waterproofing method for flat roofs using modified bitumen sheets, commonly used in commercial and modern residential buildings.
What are the critical layers in a pitched roof system?
A typical pitched roof includes: 1. Roof Covering: Shingles or tiles. 2. Underlayment: Secondary water barrier. 3. Roof Deck: Structural base layer. 4. Insulation: Regulates indoor temperature.
Why is the layer sequence critical for water management in roof valleys?
Roof valleys handle concentrated water flow requiring precise layering: 1. Valley Liner. 2. Underlayment. 3. Roof Covering.
What is the correct order of installing roof underlayment and drip edge flashing?
- Underlayment is installed first. 2. Drip Edge Flashing goes over the underlayment at eaves. 3. At rakes, drip edge flashing is installed under the underlayment.
Why is the roof-to-wall intersection a critical integration point?
The roof-to-wall intersection is vulnerable to water intrusion due to water running off the roof toward the wall. Proper sealing involves step flashing, overlapping with house wrap, and using counter flashing.
How should roof vents and pipes be integrated to prevent water intrusion?
Roof vents and pipes are sealed using flashing collars, underlayment overlap, and sealant application. Proper integration includes step flashing, counter flashing, cricket or saddle, and sealant to prevent water intrusion.
