Gutter instincts

Monday, April 4, 2011

Illustration by Antonia Pesenti.

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They may look good, but some types of guttering can cause headaches for homeowners, not to mention potential leaks, rot, mould and worse, writes Harvey Grennan.

Fashion and function don't always go together in the world of building materials, a fact highlighted by recent concerns about high-fronted roof gutters. These are favoured by builders and designers because they hide the lower edge of the tile or metal roofing. Around Australia, they account for about 90-million metres and $1 billion worth of guttering per year.

While these gutters win points for aesthetics, critics claim they don't comply with Australian Standards or the Building Code. In NSW, a battle has been raging, with the Archicentre building advisory service, trade associations, academics and politicians on one side, pointing to the dangers, and NSW Fair Trading, which has refused to concede that there are any real problems, on the other.

The issue is that because the front of the gutter is higher than the back, water can flow over the back and into the eaves if they're clogged with debris or if there's a storm surge. This water can find its way into the house and, over time, cause mould, rot and possibly structural damage. If there are no eaves, the situation can be worse. "Water will flow behind the brick veneer and into the cavity. The soft timber frame will begin to rot, the plasterboard will crack, the skirting boards will soften, and the wiring will become dangerous," says registered architect Angus Kell.

"The first visible sign might be something as drastic as the ceiling starting to bow or even cave in."

Despite the critics, there is support for Fair Trading's view. "We're not seeing any particular trends in relation to damage caused by high-faced guttering," says NRMA Insurance spokesperson Andrew Tubb. "In times of severe deluge these gutters may overflow, but we would expect to see that regardless of the guttering type in extreme weather."

There are ways around the problem, such as specifying slots along the front face, installing spouts at the high end or creating a gap between gutter and fascia so water can escape, but some of these won't work with the usual installation system, so seek expert advice. Where guttering runs across the middle of a building, box gutters may be specified. These have their own problems: if they overflow or leak, water runs into the ceiling of the room underneath.

Whichever guttering system you have or plan to install, be sure to find a good plumber. Check that the downpipes can handle a big storm, and clean out leaves and debris on a regular basis.

Damage control

Leaking gutters damage not just ceilings, walls and floors but even home foundations, says Tom Gray, Director of GumLeaf Gutter Protection. "It's imperative that excessive water be appropriately channelled away from foundations," says Gray, "and gutter protection installed to stop the downpipes from blocking. The key is to be prepared before it's too late."

Ensure you're insured

The question as to whether damage caused by high-fronted gutters is covered by insurance remains a problematic one. Insurance policies typically do not cover loss caused if a building does not comply with building laws or regulations. NRMA Insurance says it does cover claims where rain has overflowed from gutters into the roof cavity. Check with your insurance company.

User comments

I have been following this story for a while now. To comply with the relevant building codes and Australian Standards, guttering must be be installed with a continuous overflow provision. This can be in the form of a 10 mm gap between the gutter and fascia, having the front of gutter 20mm below the top of the fascia, or by having flashing between the back of the gutter and fascia. The NRMA seems to be suggesting that they will cover installations that do not comply with this requirement, a big call I would suggest. I won't be taking their word for it. I am currently designing my new home and will specify a gutter fixing product called Gutter Grip, which is a simple cost effective solution to the problem. see www.guttergrip.com.au

Fully steamed is fully mistaken! My house had appropriate no of downpipes and clear guttering but in storm events could not clear water quickly enough. I have had no issues at all since my plumber advised having gutter fitted with a 10 ml gap at back. No water entering into my house now as any overflow falls down the gap between the building and the back of the gutter. Brilliant! Why even have to worry whether your gutters have leaves in them or whether the downpipes are blocked. With the 10 mi gap solution you can have the neat look of high front gutter without the devastating backflow into the home in storm events which happens when the gutter is attached flush to the building. This is such a simple solution to a devastating problem.

The high face gutter if installed properly has no detrimental effects. The problem with most installations is they are not levelled properly and this is the cause for most water problems. I used to do roof plumbing and the company I worked for had no instances of the mentioned problems because the gutters were installed to allow the water to fall to the down pipes. No gutter will handle storm surges! If households have issues with gutters becoming clogged with leaves, then an effective leaf protection system should be installed.