roof deck gardens

Question 1

system with typically shallow depth of soil or growing medium (less than 8 inches)
not irrigated
minimum maintenance
not intended as garden or open space

Answer 1

extensive green roof

“living green roof”

Question 2

greater depth of soil medium (more than 8 inches) allows for greater diversity of plant materials
needs supplemental irrigation and more intensive level of maintenance
may be designed to accommodate open space use

Answer 2

intensive green roof “landscape over structure”

Question 3

used to keep unwanted water and moisture out of the structure below

Answer 3

waterproofing membrane

Question 4

location of waterproofing membrane

Answer 4

bottom of the system (top of structural slab)

Question 5

waterproofing membrane material selection:

Answer 5

built-up roofing (BUR)
single-ply systems
thermosetting (or elastomeric) membranes - neoprene/EPDM
thermoplastic membranes derived from plastic polymers - PVC
modified bitumen
hybrid or composite membranes
fluid-applied membranes - asphalt emulsions, silicones, neoprene

Question 6

used to prevent damage from root penetration

Answer 6

root barriers

Question 7

location of root barrier

Answer 7

directly over or part of waterproofing membrane

Question 8

root barrier material selection

Answer 8

polyethylene sheets

polypropylene geotextile fabrics

Question 9

used to protect waterproofing membrane

Answer 9

protection board

Question 10

protection board material selection

Answer 10

semirigid sheets of cement board or mineral-reinforced membrane
plastic or polyethylene sheeting
polystyrene boards

Question 11

used to keep heat out and cool air in

efficacy measured by its R-value (thermal resistance)

Answer 11

insulation

Question 12

location of insulation

Answer 12

above waterproofing membrane

Question 13

offers lightweight alternatives to soil or other fill material to lessen structural load

Answer 13

lightweight fill material

Question 14

lightweight fill material material selection

Answer 14

polystyrene products - “geofoam” or “geoblock”

Question 15

2 types of geofoam products

Answer 15

xPs, ePs

Question 16

type of geofoam that is planar

extruded polystyrene board

Answer 16

xPs

Question 17

type of geofoam product that is block-molded expanded polystyrene
available in larger sizes

Answer 17

Eps

Question 18

facilitates positive flow of excess water

Answer 18

drainage materials

Question 19

location of drainage materials

Answer 19

should be continuous across the top of the waterproofing membrane (and insulation if any)

Question 20

drainage materials material selection

Answer 20

crushed stone
lightweight aggregates (expanded clay, balled clay, expanded shale)
drainage mats and panels and reservoir mats and panels

Question 21

used to keep the fines of a soil mixture or growing medium from migrating into the drainage layer

Answer 21

filter fabrics