Page 533 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

Chapter 8 Rainwater systems

Systems and materials used in gravity

rainwater systems

The principle of any guttering and rainwater system is to remove the rainfall in
such a way that it does not:
l constitute a nuisance for the occupiers of the dwelling, or
l damage the building structure or the building foundations or those of any
adjacent building.

Domestic gutter and rainwater systems work by removing the rainwater that
runs off roofs, in channels known as gutters, and discharges the water, via
rainwater pipework, safely away from the building structure by gravity. The
water may be discharged into:

l a surface (rain) water drain, used where the dwelling has a separate system
of drainage for both foul water and surface water
l a combined sewer – a combined system of drainage where both foul and
surface water discharge into a common drainage system
l a watercourse (stream, river, etc.), where the water discharges direct into a
flowing, nearby water source
l a soakaway drain – a specifically designed and located pit, sited away from
the dwelling, which allows the water to soak away naturally to the water
table
l a rainwater harvesting system for further use within the dwelling; these are
specifically designed to serve WCs.

The types of materials used for rainwater systems include:
l PVCu
l extruded aluminium
l cast iron
l copper.

Gutter systems and components

Over the years, gutters have been manufactured from many different materials
and in many different profile shapes. In the past, the gutter profile was designed
in line with the housing styles of the time. For example, the ornamental gutter
profile (Ogee or OG) was designed during the Victorian era in the mid to late
1800s. As we shall see, a modern Ogee profile is still available today to give a
dwelling a ‘period’ feel to its exterior.
In this part of the chapter, we will look at modern materials and profiles, as well
as the different types of fittings for guttering and rainwater pipework and the
typical methods of jointing:
l PVCu guttering systems
l cast iron guttering systems
l extruded aluminium guttering systems
l jointing guttering of different materials.

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