Guttering is a vital part of any roofing system, but if you are looking to build or renovate, you may not be aware that gutters come in a range of styles, colours, and profiles. Choosing the right one and having it installed correctly will ensure your home remains safe, retains its integrity, and continues to look fantastic for years to come.
Here are the most common Australian gutter types.
What are rain gutters?
Rain gutters are narrow channels or troughs designed to collect and divert water to suitable drains and channel water away from a building’s base. This prevents leaks in sub-floor spaces, protects painted surfaces by reducing water exposure, helps to reduce erosion, and provides a means to collect rainwater for later use. Typically, they are suspended beyond the roof edge and below the projected slope of the roof.
Technically, every type of gutter is a rain gutter.
What are the different types of gutters?
In terms of gutter types in Australia, while they are all designed to direct water away from your house, there are different types and styles, and they don’t all work the same way. Factors to consider include the weather conditions in your area, price range, and aesthetics. This includes their colour, and if you want them to be seen or opt for low-profile versions that are virtually invisible from the front of your home.
Box, trough, or parallel gutters suit roofs close to walls, are usually rectangular, placed between two parallel surfaces, and are “boxed” or positioned into the edge or middle of a roof. One of the advantages of box gutters is that they are virtually invisible from below.
However, they need to be made from high-quality materials such as COLORBOND® steel and need to be fitted with an emergency overflow. This is so water can be diverted if the gutter is blocked or after heavy rain. Without an overflow, water will accumulate on the roof and/or go straight into the roof space. Debris should also be regularly removed from box gutters, so they should be deep and wide enough to maintain easily.
Fascia gutter. Image from GME Plumbing
Also known as eaves gutters, fascia gutters are commonly used on houses where fascia boards have not been installed over the rafter tails. They combine the fascia and the gutter to create one system, thus eliminating the need to install a separate fascia system. Instead, the fascia gutter is installed directly onto the roof’s rafters.
Fascia gutters are made from either ZINCALUME® or COLORBOND® steel and come in a range of profiles and colours and in either a plain or slotted finish. They are installed on the roof’s outside edges, and although visible, come in a range of attractive and decorative shapes.
Square gutter. Image from Steeline
As the name suggests, square gutters have a square appearance, come in either a lo-square or hi-square profile, and are available in various sizes. They have a high capacity so can cope with large amounts of water easily. Square gutters are generally made from galvanised ZINCALUME® or COLORBOND® steel. They have a modern profile and are available in a wide range of colours to suit most styles of homes.
Round gutter. Image from Stratco
Also known as half-round gutters, round gutters look like a circle that has been cut in half. The open half faces the roof, and they are either completely semi-circular in shape or have a straight back. Smooth line gutters are similar to half-round gutters but have a flat back, are half-rounded in the front and fixed using internal brackets.
Because they have such a wide diameter, they can deal with large amounts of water well. They are also largely self-cleaning as their “C” shaped base prevents leaves and other debris from falling into the gutters, so are ideal for homes surrounded by trees. Round gutters are typically made from galvanised, ZINCALUME® or COLORBOND® steel and available in a wide range of colours. Their smooth, clean look makes them particularly suitable for modern, Tuscan, or Spanish-style homes.
Quad gutter. Image from Steeline
Also known as “D” gutters, quad gutters are one of the most popular styles of gutters as they suit new homes as well as seamlessly integrating with the existing gutters in older Australian homes. They are available in different widths and profiles, and with or without slots. The slotted varieties are especially favoured because they are constructed to handle water overflow in areas with heavy rainfall. Quad gutters are generally made from galvanised, ZINCALUME® or COLORBOND® steel.
What are the installation requirements?
Installation requirements vary by state, however, typically, gutters must be installed with a “fall” so water flows towards the drain connection or downpipe. Gutters with an inadequate fall will allow water to pond, which will shorten the life of gutters and encourage mosquitoes to breed.
Guttering should be installed by a licensed roofing contractor. This will ensure that water will flow off the roof efficiently — even after heavy rainfall — and that any overflow is prevented from flowing back into the home. If the home has a water tank, it will also ensure water catchment is maximised.
Roofing contractors will take the pitch, size and material of the roof into account when designing the appropriate stormwater drainage system or water catchment. They will also ensure the selected guttering material is compatible with other elements of the roof.
Gutters, flashings, and downpipes must:
- Be manufactured in accordance with AS/NZS 2179.1 for metal.
- Be manufactured in accordance with AS 1273 for UPVC components.
- Be compatible with all roofing materials in accordance with BCA Vol 1 188.8.131.52.
- Not contain any lead if used as part of a water catchment system.
What are the implications of incorrect installation?
Poorly installed gutters will show signs of deterioration such as paint bubbling, stains on the underside of eaves and rust on the underside of gutters. Gutters can be patched if the problem is minor, however, more severe gutter faults include stains down walls, around windows and in the case of skillion roofs, even on ceilings. Leaks are caused mainly by overflow due to gutters being clogged with debris or the slope towards the downpipe may be insufficient.
Blocked downpipes and drains may also lead to water overflowing gutters, which can occur after a downpour because the large volume of water can’t be drained away fast enough. An “overloaded” roof drainage system will need more downpipes installed.
Another common installation fault is if the outside edge of the spouting is higher than the inside edge, which can make overflow faults worse. These can often be remedied by drilling overflow outlets into the gutter below the danger level, or by loosening the gutter brackets so that the outside edge of the gutter becomes lower than the inside edge.
Other implications of poor installation include:
- Rainwater ponding that may indicate that the gutters flow the wrong way.
- Rusting gutters in a house with a “party” wall which can cause water to run straight into the ceiling. Typically, roofing contractors will replace the rusted sections and remove the flashing from the mortar between the bricks.
- Accumulated soil, debris and plant material and their associated moisture that can accelerate the corrosion of gutters.
- Rusting of downpipes in the bend under the eaves.
- Rotting of the fascia due to the gutter leaking. Fascia corners are especially vulnerable to rot, as the mitred timber corner has exposed end grain.
- Box gutters overflowing into the unit below as the gutter is “boxed in” behind the façade, so they trap water.
- Stormwater sumps quickly filling up with leaves and rubbish.
Why is gutter maintenance essential?
Roofs and guttering should be maintained regularly so that faults can then be detected at an early stage and repairs undertaken before more costly damage occurs. Issues that can result from failing to do this include:
If gutters aren’t flowing correctly, it can lead to serious water damage to your guttering and your home’s roof. If water and debris start to pool, it can increase the weight of guttering and lead to roof damage as guttering can bend, buckle and begin to pull away from fixings. Pooling water can also do serious damage to roof and gutter materials. Metal components can corrode, timbers can start to decay, and tiles disintegrate. All of these can affect the structural integrity of your roof and the cost associated with major roof repairs.
If water is pooling in gutters or on your roof, it will eventually lead to leaks. This can cause a range of problems that can be expensive to fix and could even be hazardous. Water leaks can do significant damage to structural components like windows, roof timbers, floors and walls, which can affect the integrity of your home. A leaking roof can cause electrical shorts if water gets into the wiring, which can be a significant fire risk.
Clogged gutters and roof leaks can lead to a range of health risks. Rotting debris and pooling water can be a haven for cockroaches and mosquitoes, which are well-known disease carriers. Moisture and drainage problems can also lead to mildew and mould, which can cause a range of serious health problems, including respiratory issues and an increased risk of infection.
Water overflowing from gutters can lead to water pooling around the base of your home. With nowhere to drain, it can start to seep into the foundations, weakening them and causing cracks and over time, destabilise the base of your home. Improper drainage can also cause erosion problems and damage beyond your house, including in retaining walls, garden landscaping and in exterior buildings like garages and sheds.
Improper drainage and overflowing water can lead to the discolouration of your roof, stains down your walls, and a range of other visible damage around the home. Even if this isn’t serious, it will compromise the aesthetic appeal of your home and can affect the value of your property if you decide to sell in the future.