Rain gutter

[1] It is necessary to prevent water dripping or flowing off roofs in an uncontrolled manner for several reasons: to prevent it damaging the walls, drenching persons standing below or entering the building, and to direct the water to a suitable disposal site where it will not damage the foundations of the building.

Gutters prevent water ingress into the fabric of the building by channelling the rainwater away from the exterior of the walls and their foundations.

[9] Water running down the walls causes dampness in the affected rooms and provides a favourable environment for growth of mould, and wet rot in timber.

[citation needed] A rain gutter may be a: A roof must be designed with a suitable fall to allow the rainwater to discharge.

[15] Eaves gutters can be made from a variety of materials such as cast iron, lead, zinc, galvanised steel, painted steel, copper, painted aluminium, PVC (and other plastics) and occasionally from concrete, stone, and wood.

Clogged gutters can also lead to stagnant water build up which in some climates allows mosquitoes to breed.

[23] In Saxon times, the thanes erected buildings with large overhanging roofs to throw the water clear of the walls in the same way that occurs in thatched cottages.

The wooden Paxton gutters had a deep semi-circular channel to remove the rainwater and grooves at the side to handle the condensation.

In 1849 Joseph Bazalgette proposed a sewerage system for London, that prevented run-off being channelled into the Thames.

The Victorian gutter was an ogee, 115 mm in width, that was fitted directly to the fascia boards eliminating the need for brackets.

[citation needed] It is easy to install, economical, lightweight requires minimum maintenance and has a life expectancy of 50 years.

A 4-metre gutter, enduring a −5 °C to 25 °C temperature range will need space to expand, 30 × 4 × 0.06 = 7.2 mm within its end stops.

The advantages of stainless steel are durability, corrosion-resistance, ease of cleaning, and superior aesthetics.

Seamless gutters have the advantage of being produced on site with a portable roll forming machine to match the specifications of the structure and are generally installed by experienced tradesman.

[citation needed] In commercial and domestic architecture, guttering is often made from zinc coated mild steel for corrosion resistance.

There were used on domestic properties in the 1950s and 1960s, as a replacement for cast iron gutters when there was a shortage of steel and surplus of concrete.

[citation needed] They were discredited after differential movement was found to open joints and allow damp to penetrate, but can be fitted with an aluminium and bitumastic liner.

The blocks which can range from 8 to 12 inches (200 to 300 mm) can be joined using reinforcing rods and concrete, to form lintels for doors and windows.

A negative feature of foam type filters is that the pores quickly get clogged and thus need replacement due to not allowing water to pass through.

[33] PVC type gutter guards are a less costly option, however, they tend to quickly become brittle due to sun exposure.