Theoretical Analysis and Comparison of the Thermal Performance, Construction Costs, and Maintenance Complexity between a Conventional and an Intensive Green Roof

Table 3

Thermal resistance of layers of an intensive green roof (the table is structured by authors upon data collected from cost estimate for the building under construction).

Material type	Thickness	Thermal conductivity	Thermal resistance
	d (m)	λ (W/mK)	R (m^2K/W)
Substrate	0.4	0.27	1.48
Geotextile filter layer SF 100 g/m^2	0.005	0.2	0.03
Accumulation cups filled with a dedicated mix	0.06	0.13	0.46
Filter layer (with protection from roots)	0.0025	0.2	0.01
ECB-based polymeric waterproofing tape	0.002	0.26	0.01
Thermal insulation, foam glass in hot bitumen	0.18	0.045	4.00
Synthetic felt geotextile, vapour barrier	0.01	0.19	0.05
Lightweight concrete	0.13	0.55	0.24
Roof deck	0.30	2.6	0.12