Extensive Roof Terrace Garden

Extensive green roofs or roof terrace garden use a very apt growing medium like Expanded Clay Aggregate (ECA®) which is also a lightweight garden soil or a roof garden soil used to support plants in the grass and sedum families. They fit well on roofs with shallow to moderate slopes (flat to 4 inches in 12 pitch) and they offer you some distinct advantages that you are not going to get with any traditional roof. You can also use these green roofs on sheds, garages, and other outbuildings. Amending the soil with an application of lightweight Expanded Clay Aggregate (ECA®) can help it become well-draining aerated fertile soil that is able to support all types of plant life due to the aggregate having the capacity to withhold up to 20% water with in itself.

The greenery also helps reduce Air Pollution.

Expanded Clay Aggregate (ECA®) dramatically changes the structure of any soil it’s added to. The clay product is blended with other growing mediums, such as soil, compost, and peat, to improve drainage, retention of water, provide insulation for roots during cold and hot weather, and to increase oxygen levels within the soil. 

Expanded Clay Aggregate (ECA®is also eco-friendly and helps filter harmful constituents from the soil.

Green roofs have a positive effect on your heating and cooling costs. It’s not so much because they add insulation but rather because of the way they work with the environment. 

  • Extensive systems are shallow in soil depth (less than 6"), and are not capable of supporting larger plants, but tend to be easier to maintain.
  • Ideal for large flat roofs, low-sloped residential roofs, and retrofits. Lightweight Expanded Clay Aggregate ( ECA ) is widely used in roof-terrace gardening.
  • Expanded Clay Aggregate (ECA®) reduces 40-50% of the weight of soil.

Also applicable for: Terrace Lawn, Small Flower Plants, Flower Beds, and similar…

Filling Technique for Roof Garden Soil

Top Layer

20 % of total volume, fill up with ECA® (8-15 mm) on the top of the plants in case of planters as a dressing layer ( thermal insulation layer)

Middle Layer

60 %  of total volume, Mix with equal portion of  ECA® (2-8 mm or crushed 2-8 mm aggregate ) + Normal Soil + Manure or compost. Plantation of the turf will be done in this root zone layer.

Bottom Layer

20 % of total volume, Fill up with ECA® ( 8-15 mm ) for facilitation as a drainage layer to drain excess water in case of overwatering.

Application Technique of Lightweight Garden Soil in Roof Terrace Garden

  • Apply waterproofing solution on the concrete slab surface first. 
  • 1” PVC Drainage mat laying or alternatives.
  • 2” Expanded Clay Aggregate (ECA®) ( 8-15mm) Layer as filter Media/drain.
  • 120 GSM Non-woven Filter cloth as root permeable layer.
  • Prepare the Expanded Clay Aggregate (ECA®) mixture bed as per the Plant size requirement.(ECA 2-8 mm + Soil + Compost)
  • Plantation will be done on this growing bed of Expanded Clay Aggregate (ECA®), along with light watering. 

Keywords: Roof Terrace Garden, Lightweight Garden soil, Roof garden Soil