Going green on your roof

We are witnessing a rising popularity in green roofs. This is for a few good reasons: green roofs can be very beautiful, and they can increase the sustainability of a building design dramatically. They will save you on your energy bills, even taking into account the initial outlay. A well-designed green roof will give your building thermal regulation, which may mean no need for air conditioning in summer and heating in winter.

They will make for healthier buildings and healthier inhabitants. Plus, you could harvest vegetables or flowers. They might even accommodate nocturnal animals and act as animal shelters.

What to consider when planning a green roof

First up, if you are planning to convert an existing building, get your roof inspected to assess its structural integrity and suitability.

You need to consider the weight of the soil and plants in any calculations about construction, so be sure to get accurate estimates about these. Take into account that plants will grow, so the weight will increase over time, so your roof needs to be even stronger than it might first need to be.

You also need to choose soil that is very permeable, and perhaps consider plants such as succulents that don’t need too much water. You certainly don’t want to have water pooling on your roof.

Layers of a green roof

Typically, a green roof has seven layers over the structural components. At the base is a waterproofing membrane, usually followed by a root barrier layer, then an optional layer of insulation. Next is a drainage layer, followed by a filter fabric, then the soil or growing medium and, finally, the vegetation.

The depth of your growing medium will determine the type of green roof. Extensive green roofs have a shallow layer of the growing medium and provide the environmental benefits of a green roof but can’t safely support regular foot traffic. Intensive green roofs can have a metre-deep layer of the soil or growing medium, and can support larger plants and hold more water. They can weigh a hefty 180 to 500 kg per square metre, so require a very strong structural base. This makes them harder to retrofit to existing buildings.

Roof Inspection Reports inspects green roofs
Once you’ve done your research and have a plan for a green roof, contact Roof Inspection Reports for a full professional assessment of and report on its safety and integrity.

Contact us today for all matters regarding green roof safety.