Green flat roofs – what are the advantages and disadvantages?
Since we are allowed to build almost any type of roof on our property, we are considering a landscaped flat roof because the modern look is very appealing to us, and landscaping is supposed to have many benefits such as insulation and phase shift. Unfortunately, I can't find much information on the disadvantages. My wife's biggest concern is that vermin and birds will settle in there and we will have constant problems, such as bird droppings on the patio and/or bugs, spiders and wasps in the house. What experiences have you had with using a green roof?
Answers
We built a flat roof, the only reason against green roofs was the extra cost. It would have cost us $70/m² net.
But we had no concerns about vermin, etc. Why should we have? Why should we? How are they supposed to get through the waterproofing?
Structural design should be adjusted for increased weight.
The slope should be increased from a minimum of 2,2 % to a minimum of 4,5% – this requires a change in elevation in other areas.
We greened the 9 x 5 m garage and are now waiting for it to sprout again in time for spring.