News and Information relevant for building and architectural engineering

Notes on paving.
In many countries, external paving must remain permeable for water so that rain can enter the ground and the aquifer.
Unfortunately, the most common practice I have observed here almost everywhere, is that the paving is laid on a layer of concrete, so the whole paved area leaves a completely sealed surface.
This practice is unsustainable and even illegal in many countries . 
No specific permeable product on top of the pearmeable layers the paving is laid on is needed.
You can use stone, concrete or other materials for the pavers. It is the construction under the material with permeable joints, which must be permeable.