Driveways on Roofs and Plaza Decks

General Information Regarding Driveways on Rooftops


Wheel loads on roofs

Driveways on rooftops require both a stable construction and adequate load-bearing capacity. As wheel loads lead to enormous concentrated loads due to their relatively small surface area, sufficient load distribution has to be available. This can be achieved through the use of load-distributing plates or through sufficiently thick layers of growing medium.


Stone thickness of pavements

The stone thickness has to be properly calculated and should be selected in accordance with the loads. Lesser loads (e.g. cars only), do not call for the paving to be as strong as if used with higher loads. When both car and truck traffic occur, the rolling structural loads can lead to distortions. Selecting a larger stone thickness will result in a larger bearing surface between the stones, which will do more to counteract distortions.


Surrounds on roofs

Steering, breaking and accelerating on driveways can lead to enormous horizontal forces being created. In order to direct these forces away from the roof’s waterproofing, measures such as laying slip sheets may be required. The forces are then transferred into stable edging.


System Build-Up

  • 1: Paving e.g. concrete pavers, joints filled with bedding material *
  • 2: Bedding layer, 1.2–2 in. well graded crushed sand, lime free, sieve size 3/8 in. to # 100
  • 3: Base layer, compacted * (if applicable), crusher run, lime free, sieve size e.g. 1 1/2 in. to # 200*
  • 4: Filter layer Filter Sheet PV
  • 5: Drainage and Protection layer Elastodrain® EL 202
  • 6: Separation layer Slip Sheet TGF 20, 2 layers

    * height of paving and of base layer depend on expected load.
System Build-Up
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Technical Data

for light vehicles up to truck class 1:

Build-up height:
from 5 ½ in.
Weight, saturated:
from 58 lbs/sq. ft.

for trucks (class 2–8):

Build-up height:
from 11 ½ in.
Weight, saturated:
from 123 lbs/sq. ft.

Standard Architectural Details:
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