LIVING ROOFS

PROJECTS

University of Waterloo - Quantum Nano Center
Sisters of St. Joseph
Guelph Civic Centre
Grand River Conservation Authority (GRCA)
City of Cambridge
Centre for International Governance and Innovation (CIGI)
Research in Motion, Northfield Drive

SERVICES

Consultation

At NEDLAW, we’re experts at determining how a living roof will best fit your specifications. We offer full project consultation — from design and customization to scheduling and project management. As well, we can conduct a feasibility study and impact assessment for LEED building projects.

Maintenance

We provide a two-year maintenance program for all new installations as part of our warranty. Our trained staff will complete this work and deliver a report to you. For the first two months, we’ll visit your roof weekly to irrigate and make sure the vegetation becomes established. For the remainder of the first year, we’ll visit your roof biweekly. In the second year there will be four visits: a spring cleanup, two mid-summer check-ins and a fall cleanup.

We also offer customizable maintenance services for existing living roof systems.

Clean-up Service

  • Vegetation will be cut down
  • The grow medium will be topped up
  • The mats will be levelled
  • Fertilizer will be applied, if specified in your contract
  • Unwanted species will be removed

Check-up Checklist

  • Photos will be taken and the general condition of the roof will be documented
  • The drains will be cleared of any debris
  • Any garbage will be removed
  • Ballast will be cleaned and weeded
  • Water levels in the drainage board will be measured and documented
  • Weather conditions will be documented
  • Unwanted species will be removed

PRODUCTS & COMPONENTS

Where All the Pieces Come Together

Nedlaw  has a full range of products, services and resources to accommodate any roof job — from smaller, off-the-shelf installations to larger, customized projects. We have the expertise to integrate outside systems and we can work with all manners of existing roofing systems.

Native and Sedum Vegetation Mats

Our sedum and native vegetation mats are available for direct sale. Contact our office make a purchase.

LiveRoof Modules

We can source LiveRoof modules for your green roof project.

Separation Bar

We provide perforated aluminum edging to act as a crucial barrier between vegetated and non-vegetated areas on a Living Roof. The separation bar also ensures that vegetation stays in place. Filter cloth is fastened to the side of the separation bar that is in contact with the soil to prevent the soil from migrating through the edging.

Drain and Anchor Boxes

We create custom-fitted boxes, from our perforated aluminum edging, that protect roof accessories from being hidden or damaged by vegetation or other Living Roof system components. It also allows for easy maintenance access. The inside of the boxes can be filled with crushed stone or gravel.

Water Retention and Drainage Modules

ModiTM and Green InnovationsTM provide modular drainage systems that consist of specially designed interlocking plastic squares. Several drainage cups retain and circulate water to ensure proper storm-water management and effective moisture levels throughout the life-cycles of your Living Roof. Drainage boards provide enough weight resistance to allow personnel and equipment to travel over the installed system. These modules are made from post-consumer recycled and pre-consumer recycled content.

Modi Garden GridTM

Garden GridTM consists of uniquely shaped interlocking pieces that can be formed to fit any space or detail. Garden GridTM is highly resistant to compression, making it ideal for paths and walkways.

Nedlaw Living Roofs GroMediumTM

The Nedlaw growing medium is a lightweight soil mix of organic and inorganic material that is hospitable to a wide variety of plant species. It also has superb water-retention qualities that work in combination with all of our other Living Roof system components to achieve effective stormwater management.

DOCUMENTS

FAQs for Architects

What types of vegetation are used?

There are two general types of vegetation used by NEDLAW Living Roofs. Succulents, such as sedum or stone crop, are a common type of plant used on living roofs in North America and Europe. Sedum is a ground cover commonly found in alpine regions characterized by harsh climates, which makes these plants suitable for rooftop growth. Our pre-grown sedum include eight to ten species that are decorated with both bright and earth-tone colors. The second type of vegetation used is native meadow and prairie species. This mat consists of twenty different species of prairie grasses and wild flowers that are indigenous to Southern Ontario. These plants flower throughout the summer and provide a mixture of bright colors. Like sedum, this native vegetation is found growing naturally in tougher conditions where soil and moisture are both limited, which makes it ideal for rooftop conditions.

What types of living roof systems does NEDLAW install?

NEDLAW Living Roofs typically use a layered living roof system as it provides greater flexibility in design and application compared to a modular system. However, we can produce and install modular systems if requested.

What component materials are included in a layered living roof system?

No matter the type of roof that you start with, there are seven general layers that typically compose a living roof: the structural support, roofing membrane, a root barrier, drainage, a filter, growing medium, and vegetation.

Is the growing medium essentially topsoil?

No, the growing medium is a specially formulated lightweight mix designed for high water-retention capacity and a low density. Once in contact with moisture, the growing medium’s binding agents are activated to prevent soil loss due to wind and water erosion.

Are living roofs more susceptible to leaks or breakdown of the membrane?

No. In fact, a properly constructed living roof will extend the lifespan of your roof membrane, often by 30 to 50 years.

Is a new roof membrane required before an installation?

It’s very important to verify the integrity of the membrane before installing a living roof. If the membrane is still in good condition and is at less than half its expected lifespan, the membrane will not need to be replaced. However, if the membrane is in poor condition or over half its expected lifespan, the membrane should be replaced.

What types of roof decks can you install a living roof on?

NEDLAW Living Roofs systems have been built on steel, concrete and wooden roof decks.

What is the weight load of a NEDLAW Living Roofs system?

Weight load can vary significantly depending on the soil depth used. Our sedum Living Roof system requires as little as one to two inches of growing medium or as much as four inches. Accordingly, weight can vary from ten to twenty pounds per square foot. Our Native Meadow Living Roof system requires four to six inches of growing medium for a weight load of between twenty to thirty pounds per square foot.

What is the R value of the system?

The R value of our Living Roofs range from twenty to fifty, depending on the depth of growing medium.

What about the warranty?

The NEDLAW Living Roofs standard warranty guarantees: the workmanship of the installation for the life of the membrane, that all components of the landscaping system will perform as per spec for the life of the membrane, as will all vegetation from the date the installation is completed.

What are the conditions of warranty?

NEDLAW requires that all maintenance be conducted as per specification and that it be carried out by NEDLAW Living Roofs or a NEDLAW Living Roofs-certified installer. Any removal and replacement of the living roof, due to other work required, must also be completed by a certified installer.

What is the cost?

The cost of a NEDLAW Living Roofs system varies depending on materials required and the detail of the work. In general, prices can range from $8/sq. ft to $50/sq. ft. On average, prices range from $10 to $15/sq. ft.

What maintenance is required?

It’s a misconception that living roofs require no maintenance. All NEDLAW Living Roofs systems come with a full two-year maintenance package. See Service for more details.

How many Living Roofs has NEDLAW installed?

According to a 2007 industry survey, NEDLAW Living Roofs systems accounted for twenty-five percent of all living roofs installed in Ontario. By the end of 2008, we will have installed over 70,000 sq. ft. of Living Roofs.

Can a living roof system be applied towards LEED designation? If so, what points can be awarded for a NEDLAW system?

Yes, the installation of a NEDLAW Living Roofs system can be applied towards LEED designation, and will play a role in the following points:

Sustainable Sites:

  • SS 6.1: Storm-water Management – Rate & Quantity
  • SS 7.2: Heat Island Effect: Roof

Water Efficiency:

  • WE 1.1: Water Efficient Landscaping: Reduce by 50 %
  • WE 1.2: No Potable Water Use or No Irrigation

Energy & Atmosphere

  • EA 1.1: Optimize Energy Performance

Materials & Resources:

  • MR 4.1 & 4.2: Must contain 7.5 % to 15 % recycled content
  • MR 5.1 & 5.2: Must consist of 10 % to 20 % regional materials

Innovation & Design Process:

  • ID 1.1: Innovation in Design
FAQs for Engineers

Is the growing medium essentially topsoil?

No, the growing medium is a specially formulated lightweight mix designed for high water-retention capacity and a low density. Once in contact with moisture, the growing medium’s binding agents are activated to prevent soil loss due to wind and water erosion.

Are living roofs more susceptible to leaks or breakdown of the membrane?

No. In fact, properly constructed NEDLAW Living Roofs will extend the lifespan of your roof membrane, often by 30 to 50 years.

Is a new roof membrane required before an installation?

It’s very important to verify the integrity of the membrane before installing a living roof. If the membrane is still in good condition and is at less than half its expected lifespan, the membrane will not need to be replaced. However, if the membrane is in poor condition or over half its expected lifespan, the membrane should be replaced.

What types of roof decks can you install a Living Roof on?

NEDLAW Living Roofs systems have been built on steel, concrete and wooden roof decks.

What is the weight load of a NEDLAW Living Roofs system?

Weight load can vary significantly depending on the soil depth used. Our sedum living-roof system requires as little as one to two inches of growing medium or as much as four inches. Accordingly, weight can vary from ten to twenty pounds per square foot. Our Native Meadow Living Roof system requires four to six inches of growing medium for a weight load of between twenty to thirty pounds per square foot.

What is the R value of the system?
The R value of our Living Roofs range from twenty to fifty, depending on the depth of growing medium.

Can a living-roof system be applied towards LEED designation? If so, what points can be rewarded for a NEDLAW system?
Yes, the installation of a NEDLAW Living Roofs system can be applied towards LEED designation, and will play a role in the following points:
Sustainable Sites:

  • SS 6.1: Storm-water Management – Rate & Quantity
  • SS 7.2: Heat Island Effect: Roof

Water Efficiency:

  • WE 1.1: Water Efficient Landscaping: Reduce by 50 %
  • WE 1.2: No Potable Water Use or No Irrigation

Energy & Atmosphere

  • EA 1.1: Optimize Energy Performance

Materials & Resources:

  • MR 4.1 & 4.2: Must contain 7.5 % to 15 % recycled content
  • MR 5.1 & 5.2: Must consist of 10 % to 20 % regional materials

Innovation & Design Process:

  • ID 1.1: Innovation in Design

For more information, visit Canadian Green Building Council.

FAQs for Building Managers

What types of vegetation are used? Do they flower throughout the growing season?

There are two general types of vegetation used by NEDLAW Living Roofs. Succulents, known as sedum or stone crop, are a common type of plant used on Living Roofs in North America and Europe. Sedum is a ground cover commonly found in alpine regions characterized by harsh climates, which makes these plants suitable for rooftop growth. Our pre-grown sedum include eight to ten species that are decorated with both bright and earth-tone colors.
The second type of vegetation used is native meadow and prairie species. This mat consists of twenty different species of prairie grasses and wild flowers that are indigenous to Southern Ontario. Like sedum, this native vegetation is found growing naturally in tougher conditions where soil and moisture are both limited, which makes it ideal for rooftop conditions.
These plants flower throughout the summer and provide a mixture of bright colors.

What are main benefits of a NEDLAW Living Roofs system for the building and its tenants?

Again and again, Living Roofs have proven to bring a wide range of economic, social and environmental benefits to building owners and tenants, including:

  • Energy savings as heat transfer is reduced between the building and its outside environment
  • Reduced life-cycle capital costs
  • Reduced costs for roof maintenance
  • Additional amenity space for tenants that did not previously exist
  • Enhanced aesthetics of a building with added green space
  • Improved psychological benefits, as people are happier when exposed to or have access to greenery
  • Increased real-estate value, as buyers are willing to pay more for access to or a view of green space.

What maintenance is required?

It’s a misconception that Living Roofs require no maintenance. All NEDLAW living-roof systems come with a full two-year maintenance package. See Service for more details.

What about the warranty?

The NEDLAW Living Roofs standard warranty guarantees the workmanship of the
installation for the life of the membrane, and that all components of the landscaping system will perform as per spec for the life of the membrane, as will all vegetation from the date the installation is completed.

What are the conditions of warranty?

NEDLAW requires that all maintenance be conducted as per specification and that it be carried out by NEDLAW Living Roofs or a NEDLAW Living Roofs-certified installer. Any removal and replacement of the living roof, due to other work required, must also be completed by a certified installer.

Are Living Roofs more susceptible to leaks or breakdown of the membrane?

No. In fact, a properly constructed living roof will extend the lifespan of your roof membrane, often by 30 to 50 years.