Reliable Green Roof Installation

Yes, it is usually possible to install a green roof on an existing building. We will just need to assess your current roof structure first, to ensure that it has sufficient structural capacity to support the additional weight. Indeed, because green roofs consist of several different layers, including a waterproof membrane, a drainage layer, a layer of growth medium, plus your plants, they can have a hefty combined weight overall. There are usually ways around this for smaller properties, for instance, by opting for a lighter extensive green roof, with a shallow soil layer and more lightweight plants. If you’re considering installing a green roof on your current property, it’s always best to get in touch and we can send our structural engineering team out to conduct a full survey before coming up with a green roofing plan to suit you.

The thickness of your green roof will depend on the type of green roof that you choose to install. Whilst intensive green roofs have quite a thick soil or growth-medium layer in order to support larger plants, shrubs and trees, extensive green roofs have a relatively shallow planting layer. To give you a better idea, extensive green roofs typically have around two to six inches of growth medium, whilst the depth of the soil on intensive green roofs ranges between six and 24 inches. Semi-extensive green roofs (sometimes referred to as semi-intensive) fall somewhere in between the two.

It is important to consider how the thickness of your new green roof system will affect the structure of your building. In some cases, we may have to install additional structural support to meet your green roof system requirements. Nevertheless, we have the expertise required to plan around this and recommend plants that are ideal for your property and personal tastes, regardless of the thickness of your roof.

Green roofs typically require guttering just like any other type of roof, as they still need to manage water runoff and rainfall. Whilst green roofs can absorb and retain some of the rainwater that falls on them, particularly in the case of detention green roofs, they may not be able to absorb all of it, especially in the UK where we are prone to bouts of heavy rain. Guttering helps to collect any excess water and direct it towards an appropriate drainage system, preventing water from damaging your plants, your building and the surrounding area.

Guttering also helps to prevent your growth medium from eroding, serving to protect the vegetation on top of your green roof. Without proper guttering, rainwater could create channels or wash out areas of your soil, leading to uneven growth and even, the complete erosion of your roof structure.

In some cases, we may design your green roof to include a system of built-in gutters and downspouts to create a more seamless green roof aesthetic.

The average green roof should last somewhere between 20 and 50 years. Nevertheless, with correct green roof installation and regular green roof maintenance, you may be able to extend the lifespan of your living roof even further. Indeed, adequate green roof maintenance is critical for longevity. We provide all kinds of green roofing maintenance and repair services, including regular inspections and frequent cleaning of your draining systems, where we will also check for any leaks or damage to your waterproofing membrane. We can also help to monitor the health of the vegetation on your green roof to ensure it continues to thrive and protect the layers underneath from potential erosion.

Because Southern Cross Projects Roofing & Waterproofing uses only the finest materials to design and construct its green roofs, including our innovative liquid waterproofing sealant, our green roofs should last for several decades, continuing to benefit you, your building and the environment for years to come.

At Southern Cross Projects, we specialise in roofing and waterproofing. Alongside waterproofing roofs, one of our specialities is basement waterproofing. We use a liquid polyurethane for the walls, to create a watertight seal that keeps the basement dry.

Not all green roofs in the UK require planning permission. In general, extensive green roofs that are less than 200 mm deep and that cannot be seen from a public road or footpath are permitted without applying for planning. Nevertheless, if your green roof is deeper than this or is to be installed on a listed building, on a building within a conservation area or at another designated site, planning permission may be required.

For larger, more complex green roof projects, such as intensive green roofs and green roofing solutions that necessitate alterations to the existing roof structure for additional support, planning will also be necessary.

Regardless of the size and type of green roof that you have planned, it’s important to consult your local planning authority in advance to ensure you meet any additional rules and regulations for green roof installations in your area. Southern Cross Projects Roofing & Waterproofing would be more than happy to help you with this, whether you’re planning a domestic green roof or installing a green roof as part of a larger renovation project.

The frequency with which you need to maintain your green roof will depend on the type of green roof you install and the type of plants you grow there. For instance, extensive green roofs generally require less maintenance than intensive green roofs because they have thinner soil profiles and fewer, hardier plants. As a general rule, extensive green roofs will need maintenance a couple of times a year, whilst intensive green roofs could benefit from weekly or monthly attention to stay looking their best.

Having said that, all green roofs require some maintenance to ensure longevity and optimal performance. This includes removing weeds, pruning, inspecting your drainage systems and checking for general damage.

Factors such as the local climate and the location of your building can also have an impact, so it’s best to get in touch if you’re unsure. We offer affordable and friendly green roof maintenance that will save you costly repairs in the long run.