Green roofs are built for environmental purpose specifically for solving the problem of conventional roofs. It is popular in Europe and presently it is attracting other developed countries specially homeowners and business concerns. The existing period of the green roofs are longer than than the conventional roofs as it conserves energy.
It reduces the cooling and heating costs. It produces natural insulation which creates a cool atmosphere for people and animals, eventually results in absorbing storm water and prevents the cost of drainage systems. Moreover, it improves the air quality and decreases urban heat island effect. Green roofs are changing the architects way of designing buildings and providing ecosystems services, services which plants supply to the people and changing the landscape of the urban area.
Difficulty level: Moderately Challenging
Time required: 2 to 3 days
Resources required
1. Liner (for sloped roofs)
2. Root barrier
3. A moisture membrane
4. Low root plants
5. Well mixed soil
Estimated cost: $8 to $20 per square feet of the roof
Instructions
1. There are two types of green roofs extensive and intensive. The former one is implemented more. The first step is to verify the kind of irrigation system required. The green roof installation expert will guide you with a proper irrigation system. You have to determine the roof load capacity of your roof surface as extensive green roofs mostly weighs within 12-18 lbs per sq. ft. Basically, it takes almost ten to twenty pounds of pressure per square foot. So, it is studied that a twenty-foot-square garden, filled with wet soil and plants will weigh thousands of pounds. Further you have to be more cautious so that it doesn’t fall down.
2. To design your roof place four different trays, surrounded by a simple wooden frame, use galvanized steel corrugated sheeting on top. It acts as a moisture barrier or appoint an expert to design and construct the watering system for your green roof.
3. For a flawless roof put down a basic pond liner which prevents water to pass from flowing into the building. The plant roots will be away from entering into the building structure.
4. You need to follow this step only if you have a slope roof as it requires to have a grid set up over the liner to keep the dirt from descending downwards.
5. According to the plant load you need to put heavy plants like low-maintenance moss. Before planting mixing and laying potting soil is important which depends on the kinds of plants.Generally the mineral content of the soil is based on sand, dirt, organic matter including peat moss. The water hoarding material and the organic material called soil mist which helps to decay and fertilize the garden roof, further soaks up water and dries the soil.
7. After laying the soil plant low root plants such as sedium spurium plants, prairie flowers or moss. Coastal and the plants that are upland ridges are prefered because it is grown mostly in dry and exposed conditions.
Frequently asked questions
1. On what type of roof, green roof is built?
Green roofs are built both on upgrade existing roof or on a new roof. If upgrade then the best time to build is when an existing roof requires to get repaired or replace a new one. If done on a new apartment then directly a green roof can be installed which doubles the life of the roof membrane and reduces your heating and cooling budget.
2. If there is slope, what kind of waterproofing is essential to install?
It is essential to use a single ply membrane which is made by special tools and equipment.
3. Which season is appropriate for building green roof?
It is better to start your project in the fall as it is the suitable time to plant and an added advantage of growing good root system in the cool fall temperatures, so organize your plan from late summer.
Quick tips
Avoid plants that don’t like wind and retain lot of moisture such as tap rooted plants as it will hinder the drainage system on the roof. Water only once a day.
Things to watch out for
Irrigation system should be done by an expert as drainage system is very important for the moisture to pass otherwise it may crash down because a huge expense, time and effort will be invested. Grow plants that can withstand almost all kind of weather conditions. To balance moisture, perlite lightens soil can be used. Extensive green roofing is better as it requires less weeding and watering. If you plan to build it without any engineers then a constructional background is a prerequisite.
