The drains are used to collect rainwater in order to evacuate it in a sump or to the rainwater network.
Drainage of a lot helps to manage the problems of water infiltration. This system is placed at the foot of the foundations of a building, so as to limit the humidity that may damage the concrete or the concrete slab.
- This installation consists in evacuating the water present in excess in the ground, by means of buried pipes.
- These pipes are drilled in the upper part to collect water from the ground.
- The walls of houses can be isolated by a geotextile or membrane to channel the water to the drains.
- The collected water is then evacuated by a sump if one wishes an infiltration with the parcel, or more traditionally towards the network of rain water.
Installing a drain
The use of drains is particularly recommended for sloping or clay and sandy soils. The principle of the drain is simple:
- rainwater is conducted underground, through pipes (drains) to a containment pit
- these pipes from 100 to 160mm in diameter are covered with geotextile felt or stones
- the drain is usually placed along a wall of foundations.
Underground drainage requires a significant investment, the efficiency and performance of which may be compromised as a result of improper installation or lack of maintenance of drain outlets. A field visit can often detect clogged, collapsed and even covered with earth and vegetation. Several factors are at the root of these problems and some of them can be spared or renewed with better layout and regular maintenance of drain outlets.
Use:
In addition to contributing to the efficiency and continuity of the drainage system, a well-developed drain outlet will announce the degradation of the environment. It is not uncommon to notice a scour under an unprotected drain outlet. The speed of the water at the outlet of the drain and the impact produced by the fall of the water are mainly responsible for this situation. Also, the layout of the exit must counteract the action of rodents, reduce the impact of floating debris and warn the damage caused by the machinery.
Location:
The drain outlet is usually located at the lowest point of the drained parcel. However, it must not be placed where surface water is spreading in the ditch or stream. If this is the case, then it will be necessary to refer to the sheet dealing with plugs to ensure the stability of the structure. Where possible, it is best to locate the drain outlet in a ditch rather than a stream to prevent breakage caused by ice movement.
Development of a drain outlet:
A well-constructed drain outlet includes a rigid pipe, a removable grill, soil erosion protection at the outlet of the rigid pipe, and a suitable indication for locating the discharge mouth.