ZinCo Canada Inc.

What changes, if any, need to be made to the roof installation in order to be able to build a Green Roof?

In the first place a Green Roof will add extra weight. The roof and the building construction must be checked by a structural engineer to ensure that the additional loads are acceptable. In addition, the waterproofing membrane should be of sufficiently high quality and matched in life expectancy to that of the Green Roof. Finally, roof details like roof edges and roof penetrations (drains etc.) need to be adjusted to accommodate the Green Roof. Again, asphalt shingles cannot be used under a Green Roof.

What types of plants can you grow on a Green Roof and will they survive our climate?

Green Roofs have been successfully installed in many places in the world with very diverse climates. These installations include Scotland, Denmark and Sweden in the cold extremes as well as Greece, Spain and Singapore in the warm climates. The plants and the growing medium in particular need to be chosen to suit the local climate and growing conditions.
In general, as the depth of the growing medium increases so does the range of available plants. With depths of 30 cm and higher; perennials, shrubs and even trees can be grown. Taller trees and shrubs will need special anchoring systems to hold them in place.

Is irrigation needed?

The Zinco Green Roof system has a number of different drain layers with differing water holding capacities for flat roofs. Each drain layer has cup-like depressions which are designed to hold and store water. The depth and profile of the cup increase to increase water holding capacity in the drain layer. The drain layer needs to be chosen with a view to the water requirements of the plants used for the Green Roof. In turn, the water requirements of the plants depend upon the type of plants used and the local growing conditions. Extensive Green Roofs with their drought loving plants will require little water and in most cases will not require irrigation once the plants are established. Watering or irrigation will generally be required immediately after planting and until the plants have rooted properly.
The unique problem with the sloped Green Roof is that water will seep to the bottom leaving the upper portions dry. In warmer climates and on steeper pitched roofs therefore, irrigation may be required to maintain healthy vegetation cover.

What happens with the Green Roof in the winter?

The vegetation on the Green Roof reacts to the seasons the same way that plants growing on the ground do. In the winter the plants will go dormant but in the spring they will regenerate either from buried roots or from stems that persist over the winter. The growing medium will freeze as will any water left in the drain layer. This is normal and will not damage the Green Roof system or the waterproofing roof membrane.

How much maintenance does a Green Roof need?

After the installation of the Green Roof it is important to make arrangements for proper maintenance. Plant growth, especially in the first few seasons, needs to be carefully monitored. Areas of open soil will quickly be colonized by undesirable weed growth. Depending on the type of vegetation and the size of the plant free area, plant material needs to be replaced to encourage the vegetation layer to close in as soon as possible.
Long term maintenance is different for each type of Green Roof. Extensive Green Roofs usually require only an annual or biannual weeding which includes removal of tree seedlings and undesirable weeds. The European experience shows that the plant communities on Green Roofs gradually change under the influence of various environmental factors. Some 'newcomers' are therefore quite acceptable.
The intensive Green Roof with its more diverse vegetation cover will require ongoing maintenance much like any conventional garden.

What changes, if any, need to be made to the roof installation in order to be able to build a Green Roof? In the first place a Green Roof will add extra weight. The roof and the building construction must be checked by a structural engineer to ensure that the additional loads are acceptable. In addition, the waterproofing membrane should be of sufficiently high quality and matched in life expectancy to that of the Green Roof. Finally, roof details like roof edges and roof penetrations (drains etc.) need to be adjusted to accommodate the Green Roof. Again, asphalt shingles cannot be used under a Green Roof. What types of plants can you grow on a Green Roof and will they survive our climate? Green Roofs have been successfully installed in many places in the world with very diverse climates. These installations include Scotland, Denmark and Sweden in the cold extremes as well as Greece, Spain and Singapore in the warm climates. The plants and the growing medium in particular need to be chosen to suit the local climate and growing conditions. In general, as the depth of the growing medium increases so does the range of available plants. With depths of 30 cm and higher; perennials, shrubs and even trees can be grown. Taller trees and shrubs will need special anchoring systems to hold them in place. Is irrigation needed? The Zinco Green Roof system has a number of different drain layers with differing water holding capacities for flat roofs. Each drain layer has cup-like depressions which are designed to hold and store water. The depth and profile of the cup increase to increase water holding capacity in the drain layer. The drain layer needs to be chosen with a view to the water requirements of the plants used for the Green Roof. In turn, the water requirements of the plants depend upon the type of plants used and the local growing conditions. Extensive Green Roofs with their drought loving plants will require little water and in most cases will not require irrigation once the plants are established. Watering or irrigation will generally be required immediately after planting and until the plants have rooted properly. The unique problem with the sloped Green Roof is that water will seep to the bottom leaving the upper portions dry. In warmer climates and on steeper pitched roofs therefore, irrigation may be required to maintain healthy vegetation cover. What happens with the Green Roof in the winter? The vegetation on the Green Roof reacts to the seasons the same way that plants growing on the ground do. In the winter the plants will go dormant but in the spring they will regenerate either from buried roots or from stems that persist over the winter. The growing medium will freeze as will any water left in the drain layer. This is normal and will not damage the Green Roof system or the waterproofing roof membrane. How much maintenance does a Green Roof need? After the installation of the Green Roof it is important to make arrangements for proper maintenance. Plant growth, especially in the first few seasons, needs to be carefully monitored. Areas of open soil will quickly be colonized by undesirable weed growth. Depending on the type of vegetation and the size of the plant free area, plant material needs to be replaced to encourage the vegetation layer to close in as soon as possible. Long term maintenance is different for each type of Green Roof. Extensive Green Roofs usually require only an annual or biannual weeding which includes removal of tree seedlings and undesirable weeds. The European experience shows that the plant communities on Green Roofs gradually change under the influence of various environmental factors. Some 'newcomers' are therefore quite acceptable. The intensive Green Roof with its more diverse vegetation cover will require ongoing maintenance much like any conventional garden.