Watering your roof? Yeah right, pull the other one!
It’s true, for centuries people have been growing grass and plants on roofs as an effective way of keeping the elements out, and it is now becoming a popular way of capping our eco friendly homes. What a pretty sight it can be too! A real talking point in the neighbourhood and may necessitate keeping a ladder close by so unbelievers can shimmy up and shake their heads in disbelief. Kids will think grandad is telling another one of his porkies, relaying tails of his eccentric neighbour who mows his roof once a year.
As long as the roof slope is thirty degrees or less you can have one too. Flat roofs are ideal.
Of course, before embarking on the journey to your own flat roof you should always get a survey completed by a reputable roofing services company to ensure that your roof can take the weight. The roof garden itself will be pretty heavy but when you water it or it rains the weight will significantly increase.
There are generally three types of green roof;
- Semi Extensive
The main difference between the three is the depth of planting, growing medium used and the types of plants they can support. An intensive roof garden has the deepest planting which obviously increases the load on the roof and therefore you should always consult a professional.
- You start with the bare roof surface which can be anything from plywood to concrete, it doesn’t really matter.
- Over this will be placed a vapour barrier. This is typically some high-tech PVC or similar.
- Some insulation will come next. Sheets of polystyrene, followed by another level of vapour Barrier.
- Next we will find some drainage material such as gravel and over that a sheet of moisture retaining material. It will save a lot of work if you can get the garden to hold on to its water for as long as possible.
- Then there is a layer of soil or growing compost suitable for your choice of plants. You are all ready to begin your planting, and the fun begins.
Suitable Plants for a Living Roof
Alpine plants are ideal for an extensive roof as it is the shallowest for planting. Unless we have a prolonged dry spell or heat wave, you will probably get away without needing to water on a regular basis. Planting depth is up to about 5 inches and will just need a clip to tidy it up once a year.
You should be able to grow some herbs and perennials in the semi extensive roof as its planting depth is up to about 7 inches. Just check the planting depth for your plants as you buy them. You may have to water a little more often than with the plants in the extensive roof.
If you are lucky enough to own an intensive roof, you can really let yourself go. With around 24 inch planting depth, you could even have a vegetable garden or your own lawn. Imagine a beautiful ornamental garden, even with a pond, on your roof.
So if this old world starts getting you down and people are just too much for you to face, you know where to go.
Thank you for reading this. I hope it has given you the nudge to get up and start your own plot with a sky view.