Agriculture Reference
In-Depth Information
Post railing
Pervious edge
Growing medium
Precast concrete slab with
metal footplate and post bolted to it
Mortar layer for leveling
Roof slab
The weight of the patio is conined to a well-deined area. The pavers' weight
and dimensions have to be approved with the structural engineer to avoid uplift
in windy conditions.
Pavers are never ixed to the roof structure, as the fasteners will penetrate the
root barrier and waterprooing membrane. The dead load of the pavers should
be heavy enough to prevent them from lying off the roof in windy conditions.
The barrier's post footings should be ixed to a slab with a protection layer under-
neath to protect the root barrier and waterproof membrane against damage
(
Figure 4.16
).
4.11.2 Floating grate
The loating grate system on top of the vegetation layer gives the public a differ-
ent viewing perspective, as they can engage with the plants more closely (
Figure
4.17
). A wide lattice should provide maximum light for the plants to grow, and
enable pathways for rainfall capture and ET. Lightweight, strong, durable materi-
als can help to minimize footing requirements, and thus structural challenges.
Where a shallow metal or rigid plastic grate loats tightly above low growing
plants, concrete footings should be sized as small as possible. The loating grate
needs to be accessible for living roof maintenance and monitoring.
The ASLA headquarters in Washington, DC, by Michael Van Valkenburgh
Associates, is a successful example of a loating grate scheme that is skilfully
incorporated into the overall roof design (Werthmann 2007).
Figure 4.17
Floating grate
Pervious grate to
allow enough light
for plant growth and
evapotranspiration
Plants
Steel beam
Precast
concrete block
Growing medium
Mortar layer
for levelling
Geotextile
Drainage layer
Air layer
Waterprooing
membrane integrated
root barrier
Roof slab
Search WWH ::
Custom Search