Typical roof garden sections

Below 2 typical roof garden sections. These are only to give an idea. Of course the designs change depending on the needs in the project.

The upper with conventional design. For drainage 2 nonwoven geotextile (filter fabric) layer and gravel in between were used on top of the waterproofing layer. (mineral drainage layer) Heavy and cost more to take the gravel to the roof. Bigger load on the concrete.

The below is with a geocomposite drainage layer, lightweight and easy to use. The drainage layer is only between 0.5- 1 kg depending on the material. ıt is factory made and tested material. The access water from the vegetation and soil comes to drainage layer and carried to channels.

Steel water storage silo / tank

Another usage of geosynthetics materials are in steel water reservoirs.

These are very practical and easy to use water storage systems.

They come with all the parts inside and you construct it on site.

Their heights are upto 4.64 meters and diameters vary from 1.85 to 30.95 meters.

Inside the steel construction there is a nonwoven geotextile liner to protect the waterproof tank liner. The tank liner can be made of PVC or other type of polymers depending on the usage.

Basement drainage of a congress hall building construction

Geocomposite drainage sheets can also be used in higher depths. Photographs here shows some applications of drainage composites. They are ready to backfill. The backfill around the composites should be made very carefully because of the height. Direct flow of gravel and backfil materials may tear or damage the drainage materials.

This drainage composite was placed on the waterproofing layer.

For house basement drainage please check other drainage posts.

Roof garden system

In the design of roof gardens designers should choose the design system depending on the local weather and plant conditions. Because the climate and the plants are different in al the world. Especially the drainage layer is important for the plants.

Below another roof garden design is shown.

On the concrete substrate there is a waterproofing membrane and a root barrier on it. But in some designs it is possible to lay a nonwoven geotextile to protect the waterproofing layer and a protection concrete could be casted. So, the root barrier may not be used depending on the type of plants.

For the drain layer a geocomposite drainage layer can be used. Because it is made of light materials. Otherwise you should use gravel for drainage and it will cause a load of about 150 kg/m2 on the building. So, it is much better to use a composite drainage layer.

The drainage layer should have a good filter layer to prevent clogging.

On the drainage layer landscaping architects may use a water retention layer.

You can use a prevegetated mat and soil as growth medium on the top.

This system may be used as a good drainage system.

Basement, cellar drainage, waterproofing

In the basements of buildings generally we have moisture problems. Even we have waterproofing water may enter the building. A good waterproofing system should be supported by drainage materials.
Geocomposites can intercept incoming water and drain it away from the structure towards the collector pipe.
To use a geocomposite drain is much easier and generally cheaper than conventional drainage systems like mineral drains. Forexample you should carry a lot of gravel to the construction site or building. It is also difficult to use heavy gravel. It is also necessary to cover the drainage pipe with a nonwoven geotextile to prevent clogging.
But a composite drainage sheet with a filter bothsides and only about less than half a kilograms per square meter you can make a better drainage system. Also the inside core of the drainage sheet should be elastic and the core should have a structure to let water go easily to all directions.

A good composite drainage system:

• Keeps wet soil away from walls
• collects and removes groundwater
• Protects the waterproofing on walls
• Relieves hydrostatic pressure

Advantages of composite drains:

• Ventilates - Prevents wall sweating and fungal growth
• Light and flexible-Readily adaptable to irregular wall configurations
• Economical - No extra accessories needed (i.a. strips, special fastenings, etc.)
• Reliable and durable

The composite drains can be used as do it yourself type of applications also.