Setting up Project SmartRoof 2.0
Three 4.2x4.2m plots were
constructed within a 440m2 Blue-
Green roof garden. One plot was
constructed like a conventional
Sensors measured heat fluxes such started as a primarily sedum mix, but
as incoming sunlight, reflected light, rapidly developed. Grass and herbs
surface temperatures, and soil and air dominated vegetation on the capillary
temperatures. Weather data was also irrigated plots.
gathered on-site.
The research plots showed distinct
extensive green roof, equipped with After placement of sedum mix differences in actual plant evaporation
a 25mm drainage mat and a 4cm blankets, 40 European plant species rates. The capillary-irrigated plots
substrate layer. were sown on the sedum carpet/ showed evaporation fluxes of ca.
substrate to observe the plants over 3mm per day (3 l./m2 per day) on
time. average during summer, with more
Two other plots were equipped with a
Permavoid 85mm drainage, storage
and capillary irrigation system, with All plots received the same initial
water storage maximised - by overflow vegetation and seed-mix as well as the
- to 30mm out of the available 80mm same maintenance and fertilisation
capacity due to the roof’s weight during the research.
restrictions. One was covered with a
4cm substrate and the other with 8cm What the results show
substrate. After the first month, the plots were
only supplied with rain. The vegetation
than 4mm per day, especially in spring
2018 – typical of vegetation in the
Netherlands.
Actual evaporation of the conventional
plot showed prolonged periods with
significant evaporation reduction
during dry spells, especially during
spring and early summer.