FINAL EXAM FLASH CARDS

What environmental benefits do green roofs and green walls provide?

They absorb CO₂, emit oxygen, clean the air, and break down pollutants like V.O.C.s

How do green roofs and green walls improve air quality?

Green walls act as biofilters and break down volatile organic compounds (V.O.C.s)

What aesthetic benefits do green roofs and green walls offer?

They make spaces more attractive and can turn roofs into usable areas

What functional benefits do green roofs provide?

They cool roof surfaces, add insulation, protect roofing membranes, and mediate storm runoff

What functional benefits do green walls provide?

They cool wall surfaces and absorb sound

What maintenance challenge comes with green roofs and green walls?

They require ongoing maintenance to keep plants healthy and systems functioning

Why are leaks harder to repair with green roofs?

The vegetation and soil layers make it difficult to access and fix the roofing membrane

How does cost affect green roofs and green walls?

They have higher initial installation and upkeep expenses compared to traditional systems

What risk does water exposure pose?

Potential water exposure damage to building materials if drainage or waterproofing fails

What structural consideration is needed for green roofs and walls?

Extra structural support is required to handle the added weight of soil, plants, and water

What is one advantage of green roofs related to temperature?

They keep the surface of the roof’s insulated envelope cool

How do green roofs improve energy efficiency?

They add insulation to the roof

How do green roofs protect roofing materials?

They protect the roofing membrane from sun exposure

How do green roofs help with water management?

They mediate storm runoff

How do green roofs enhance usability?

They make the roof into a more usable and attractive space

What is one advantage of green walls related to air quality?

They act as biofilters, cleaning the air

How do green walls handle pollutants?

They break down volatile organic compounds (V.O.C.s)

How do green walls affect temperature?

They keep the surface of the wall envelope cool

What acoustic benefit do green walls provide?

They absorb sound

What do both green roofs and green walls do for the atmosphere?

They absorb CO₂ and emit oxygen

What are the two main types of green roofs?

Intensive and Extensive

What is an intensive green roof?

A park-like rooftop system with shrubs and trees that requires regular maintenance

How deep is the growing media in an intensive green roof?

At least 6 inches deep, and can be up to 15 feet deep

What roof pitch is suitable for intensive green roofs?

Nearly flat surfaces with a pitch of 2:12 or less

What is an extensive green roof?

A shallow soil system that is relatively maintenance-free

How deep is the growing media in an extensive green roof?

6 inches or less

What roof pitch can extensive green roofs be built on?

Slopes up to an 8:12 pitch

What is a containerized green roof system?

A system where plants are grown in trays or containers placed over the membrane roof

What type of plants are used in containerized systems?

Regionally specified plants suited to the local climate

What do the trays in containerized systems cover?

They cover the membrane roof

What are green roof packs?

Bags filled with growing medium used for green roof installations

What is the primary function of green roof packs?

To provide an easy-to-install growing medium for vegetation on rooftops

What type of plants are used in green roof packs?

Regionally specified plants suited to the local climate

Why is irrigation important in green roof packs?

It must match the climate and plant needs to ensure sustainability

What is the main goal of plant and irrigation selection for green roof packs?

To match plants to the climate and minimize human intervention with water and chemicals

What is a roof garden?

A system where plants do not grow from the roof assembly but rest on top of it

Are roof gardens part of a containerized system?

No, they are separate from containerized systems

What is the growing medium in a green roof system?

The engineered “soil” mix that supports plants on the roof

Why can’t you use simple topsoil on a green roof?

It’s too heavy when wet, may contain pathogens or weeds, and dries out quickly between rains

How much clean topsoil can designers allow in a basic system?

Up to one-third of the mix

What are the components of engineered soil?

• Organic material: Clean topsoil, manure, compost

• Inorganic material: Expanded slate, shale or clay, crushed recycled brick or concrete, lava, perlite

Why include inorganic materials in the growing medium?

They are lighter than topsoil and hold moisture longer

What is the purpose of a root barrier in a green roof system?

To stop plant roots from penetrating the roof while searching for moisture

Why can’t asphalt or bituminous built-up roofing be used as a root barrier?

Roots can penetrate these materials and reach the roof frame

What are common materials used for root barriers?

• EPDM or TPO membranes (also serve as moisture barriers)

• Polyethylene sheets (placed on top of the roofing)

• Fiberglass sheets (placed on top of the roofing)

What type of vegetation can an intensive green roof support?

Small trees and large shrubs

How deep is the growth medium in an intensive green roof?

6 inches to 15 feet of engineered soil

What is the purpose of the first drainage fabric layer?

To filter soil from water

What is the function of drainage gravel?

Allows water to move horizontally across the roof

Why is there a second drainage fabric layer?

To filter gravel from water

What does the root barrier do?

Stops roots from penetrating the roof assembly

What is the role of extruded polystyrene board?

Protects the roofing membrane

What is the roofing membrane’s function?

Acts as a waterproof layer and can serve as the root barrier

What is the underlayment used for?

Provides padding if a single-ply membrane is used

What is the purpose of insulation in the assembly?

Serves as a thermal barrier if needed

What is the substrate in a green roof assembly?

The top of the roof frame that supports all layers

What type of vegetation is typically used in an extensive green roof?

Ground cover plants

How deep is the growth medium in an extensive green roof?

6 inches or less of engineered soil

What is the purpose of the moisture retention mat?

Absorbs and holds water for plant use

What does the drainage mat do?

Allows excess water to drain away from the roof assembly

What is the function of the cap sheet membrane?

Protects the underlying membrane

What role does the single-ply membrane serve?

Acts as both a moisture barrier and a root barrier

Why is underlayment included in the assembly?

Provides padding for the membrane

What is the purpose of insulation in the assembly?

Serves as a thermal barrier if needed

What is the substrate in a green roof assembly?

The top of the roof frame that supports all layers

What is the main principle of irrigation for green roofs?

Try to mimic natural conditions

Why is mimicking natural conditions important for irrigation?

It reduces the need for human intervention and supports plant sustainability

What is an active irrigation system for green roofs?

A system that uses drip irrigation to circulate water through the roof as needed

What is a passive irrigation system for green roofs?

A system that stores water in the roof assembly and lets plants draw moisture through their roots as needed

Can passive and active irrigation systems be combined?

Yes, both systems can be used together for optimal water management

How do dams function in a green roof irrigation system?

They store water in gravel beneath the growing medium

What natural condition does this system mimic?

The top of the water table or a rock shelf beneath shallow soil that holds water for plants to absorb later

What is the role of internal roof drains in a green roof irrigation system?

They control how much water the roof will store

Why must drains be placed at the appropriate elevation?

To prevent plants from drowning in soggy conditions by allowing excess water to drain

What is a closed irrigation system for green roofs?

A system where water is captured and recycled through the roof after feeding the plants

What are the benefits of a closed irrigation system?

Saves water by reusing it within the system

What maintenance does a closed irrigation system require?

Water must be treated to prevent pathogens, and fresh water must be added to control mineral buildup

What is an open irrigation system for green roofs?

A system that requires a reliable, sustainable, pathogen-free water supply brought into the system

How can open irrigation systems offset water use?

By incorporating rainwater harvesting and filtration of stored water

Why are fire barriers important on green roofs?

To prevent fire from quickly spreading across the roof

Where else might fire breaks be required?

Around roof protrusions and equipment

What are the components of Earth Mix?

Perlite, peat moss, and topsoil

What are the two main types of green walls?

Living Walls and Green Facades (Greenscreens)

What characterizes a Living Wall?

It includes a growing medium supported by the wall itself

What characterizes a Green Facade?

It provides a structural support for vines that grow from the ground

Why are these walls referred to as “Living Walls”?

Because the wall itself holds the growing medium

What are the main components of a Living Wall system?

• Containers

• Growing Medium

• Plants

• Irrigation System

• Structural Support

How is irrigation typically delivered in a Living Wall system?

Through the containers that hold the growing medium, watering roots directly

Why is container-based irrigation preferred over sprinklers or hoses?

It reduces water loss from evaporation and ensures efficient root hydration

What are the main components of a modular Living Wall system?

• Containers

• Growing Medium

• Plants

• Irrigation System

• Structural Support

How are modular units attached to the building?

They are connected to a structural grid mounted to the building’s wall

What material should the structural grid be made of?

Noncorrosive materials, such as stainless steel

How is irrigation integrated into modular Living Walls?

It is built into the modular system to keep plant roots watered as needed

What must a building’s wall be able to support for a green wall?

The saturated weight of the green wall, including media, structural system, irrigation system, and plants

What factors affect the weight of a green wall?

• Type of growing media

• Structural system

• Irrigation system

• Plant selection

What is a Vegiculture Wall?

A vertical garden designed for growing edible plants such as herbs, vegetables, and fruits

What is the primary purpose of Vegiculture Walls?

To provide fresh, edible produce in a compact, vertical format—often used in urban or limited-space environments

What components are essential for Vegiculture Walls?

• Containers or modular units

• Growing medium

• Irrigation system

• Structural support

• Sunlight access

What is a Sensory Garden?

A garden designed to stimulate the senses—sight, smell, touch, taste, and sound—through plant selection and layout

What types of plants are commonly used in Sensory Gardens?

• Fragrant herbs (lavender, mint) for smell

• Colorful flowers for sight

• Textured foliage for touch

• Edible plants for taste

• Plants that rustle or attract wildlife for sound