Rainwater

Rainwater systems

The main purpose of a rainwater system is:

1. To protect the property’s foundations.
2. Restrict ground erosion.
3. Prevent water penetration into the property.
4. Provide a means of water collection (water harvesting).

Types

1. Surface water drain: used with a separate system of drainage.
2. Combined sewer: used with a combined system of drainage.
3. Water course: used in rural areas where the rainwater is discharged straight into a river or stream.
4. Soakaway drain: a specially designed pit sited within the property boundary, which allows water to naturally soak away.
5. Rainwater harvesting: a specially designed system where water is treated at a basic level and reused within the property.

Harvesting

Rules of guttering

The fall of the gutter

Most manufacturers interpret this standard as a fall of:

1:600

(1mm drop every 600mm length)

25mm in 15m

This is now an accepted ratio in the trade, and allows the flow of rainwater to the running outlet in an efficient manner. It will also keep the gutter relatively silt free.

Modern systems will work even if there is little or no fall. This is used more often on large, commercial roof lines.