Green roofs provide habitats for wildlife and are an invaluable addition to urban gardens, particularly on sheds or garden rooms. Before embarking on this endeavor, however, it’s essential that the structural integrity of your shed roof be assessed carefully before proceeding further.
Low-maintenance designs feature mat-forming sedum plants on purpose-sold matting to create a living carpet effect, along with evergreen species for year-round color.
Preparation
Building a green roof onto your shed can be an easy weekend project that can add visual diversity and wildlife habitat to your garden. Not only is it visually appealing; green roofs also help absorb stormwater runoff, lower temperature inside buildings, reduce air pollution levels, greenhouse gasses emissions, air quality concerns and carbon emissions.
If you are creating or renovating an existing shed, or adapting an existing one to accommodate additional weight such as plant layers and waterproof membranes, before proceeding. Consult a structural engineer in order to make sure the structure can bear any additional loads safely.
As with any green roof system, constructing a frame of rot-proof wood or lightweight metal will be necessary to hold substrate (growing medium) and plants securely in place. When building this framework it should take into account what kind of vegetation will be planted in it – for instance low-growing Sedum spurium Tricolor can make great green roof plants with only occasional pruning required to look their best!
Once your frame is assembled, you must construct a drainage layer. Permeable soil mixture is best suited to this task; making one yourself is often less costly. Commercially produced options may also exist but making your own will save both time and money in the long run.
Water must drain away from a roof, so a small slope should be constructed. An optimal slope would be four to six inches. Too shallow a slope may dry out plants at the top, while too steep may cause water pooling in certain spots on your roof.
Once the drainage layer is installed, planting your green roof can begin. A popular choice is pre-vegetated sedum matting that can be installed quickly and easily; other options may include using mixed species sedums, herbs, wildflowers or shade grasses as shade providers to keep temperatures lower during summer and warmer during winter.
Installation
Green roofs typically consist of multiple layers: waterproofing to protect the shed, root barrier mat, water retention (sedum matting), growing medium and plants. When saturated with rainwater these layers can weigh up to 150kg per square metre; therefore it’s vital that your shed can support this weight before proceeding with this project. If in doubt consult with a structural engineer and construct a sturdy frame to support additional load.
Sedum plants are highly recommended for green roofs as they thrive in soilless environments without much need for irrigation, fertilization, or pesticide application. Other options available to create colourful gardens that attract wildlife include wildflowers, herbs and grasses – native species will likely have better adapted to local climate conditions, thus needing less irrigation, fertilizers or pesticides than introduced varieties.
Green roofs require a slight slope so water can easily drain away, eliminating pooled pools on or underneath your plants. You should carefully consider which slope would work best before starting, as too steep would dry out plants at the top while too shallow will prevent sufficient drainage.
Once plants have been established on your roof, it’s essential to regularly monitor the water levels. Overwatering may put extra stress on the membrane, leading to leakage over time. Keep an eye on weather forecasts; in case there’s extended dry spell, be proactive about watering it as necessary.
Once plants are established and settled into place, a tanalised timber framework must be erected over the roof using galvanised screws to secure its attachment to it. Side and top panels of this frame should then be attached directly to the roof while leaving off one section that runs along its lower edge until after waterproof membrane installation has taken place. Finally, waterproof membrane should then be fixed over both frame and sedum matting ensuring all gaps are properly sealed off.
Maintenance
Green shed roofs can be great additions to the environment and garden spaces alike, yet do require some ongoing care and maintenance in order to remain looking good and functioning effectively. Before proceeding, it is essential that the structure can support additional weight from soil and plants without leaks appearing; contact an established roofing contractor if this proves challenging.
Watering a green roof on a regular basis, particularly during dry conditions, is also essential. Sedums tend to be highly drought tolerant and don’t need much irrigation, however an occasional dose from a hosepipe or bucket might come in handy if conditions persist over an extended period.
If you use a container-style green roof, it’s essential that the growing medium and potting mix remains in good condition. If its condition starts deteriorating, this must be replaced – usually just by mixing in fresh growing medium into the old mix, and repotting all plants back in place with their new location.
As with any green roof, it is essential that weeds, grass and saplings are regularly checked for and removed when they appear. A diverse plant palette will make your green roof more resilient against attacks by pests; if certain areas seem particularly challenged by this, this may indicate puncturing or other damage in its membrane lining.
If parts of your green roof appear drooping, this could be a telltale sign that you have overwatered. Overwatering places additional strain on membranes and may even lead to leakage; to ensure optimal conditions on the roof it is best not to exceed recommended amounts; but during an unusually dry spell of weather quick waterings via hosepipe may help keep plants hydrated enough and avoid drying out too quickly.
Final Thoughts
Green roofs offer an ecologically responsible solution to traditional shed roofing. By absorbing sunlight instead of reflecting it back into the environment, green roofs can reduce urban heat island effect while simultaneously improving air quality by mitigating pollution through plant respiration and offering refuge to invertebrates as well as wildlife corridors within town gardens.
Before installing a green roof on your shed, it’s essential to carefully consider all of the factors associated with its construction and upkeep. These include its structure and surrounding environment as well as what plants you plan on growing there.
Green roofs consist of three core elements: waterproof membrane, root barrier layer and growing medium/vegetation. A waterproof membrane protects sheds from water damage while the root barrier layer keeps roots of vegetation from penetrating and damaging structures. Finally, growing medium/vegetation is added which typically comes in the form of lightweight soil mix tailored specifically for green roofs.
Select a low-maintenance, drought-tolerant plant species for your green roof that requires minimum care and upkeep. Furthermore, mix different plant species together for added resilience in your community. When caring for a green roof requires periodic inspections and maintenance visits.
Green roofs not only protect structures from structural damage, but they can also be designed to facilitate rainwater harvesting and enhance thermal efficiency within your garden shed. Furthermore, insulation may help you lower energy costs further.
Green roofs can be installed on any flat or sloped roof with an angle up to 30 degrees, although sloped roofs will require greater structural support due to their slope. Saturated with water and soil, a green roof can weigh as much as 30 lbs per square foot once complete; to make sure it can stand the additional weight load properly it must also be structurally sound and robust enough.
