22 Mar Did you get wet yesterday?
“Roof leaks and that sort of thing”
Yesterday in Melbourne we experienced some storm activity after a very warm and stable March which had seen next to no rain. According to online ABC News report http://www.abc.net.au/news/2017-03-21/victoria-storms-cause-flash-flooding/8373812 this resulted in hundreds of calls to the SES across Victoria. State Duty Officer Laura Dewildt of the SES is quoted by the ABC as saying: “The majority of the calls have been for flooding into houses, or roof leaks and that sort of thing.” In other words, the insurance companies will be busy today!
So why do some houses flood during periods of heavy rain and others don’t? Is there a gaping big hole in your roof that you have decided to not patch up? Should it be expected that your house roof will inevitably leak if it suddenly rains?
Or isn’t the whole idea of a roof that it should…. ahem… keep the rain out to start with??!!
I’m now wondering whether my local doctor’s surgery is hanging out the medical records to dry again after yesterday’s heavy rain. The beautiful old building that this clinic is housed in had undergone a significant contemporary design second storey extension a couple of years ago. When I visited earlier this year, rather than being greeted by the usual feng shui that this cute old surgery has managed to create – the place instead looked like it had been bombed! There was a drone of dehumidifiers, a flood restoration crew and plastic sheeting trying to shield the mess from the patient’s aching heads.
My doctor filled me in that flooding had occurred during the post-Christmas storms (which was the last episode of heavy rain in Melbourne prior to yesterday) and water had poured into the building whilst the staff were on holidays. They returned to soggy carpets, damaged ceilings, damage to contents, a mould infestation and significant business interruption.
Why would this happen on an architecturally designed brand new extension?
My doctor’s take on it was “there had been a problem with the plumbing” and that “hopefully it’s all fixed now” (he will know the answer to that by now I’d imagine!).
So what’s the problem here??
The plumbing regulations and Australian Standards demand overflow provision to be sized to accommodate a very large 1:100 year rain event. In Melbourne, that works out to being a huge 46.5mm (about 2 inches in the old money) of rain in 15 minutes! However, the actually diagnosis at my doctors surgery is that the building flooded simply because the second story extension roof did not comply with the overflow provision requirements. And my prognosis is that while this underlying issue is not being addressed – it’s only a matter of time until it happens again!
Basically a bucket of leaves, perhaps a plastic bag or tennis ball for good measure, and a dark cloud heavy with rain, is all it takes to catastrophically flood most contemporary new houses – all due to their lack of compliant overflow provision.
The sobering stats tell us that neither the post-Christmas 2016 storms nor the rain event of 21 March 2017 equated to anywhere near a 1:100 year rain event, yet so many buildings are leaking and flooding in what are actually very normal yearly rainfall occurrence events. Let’s face it – it’s always going to rain heavily from time to time and your roof needs to be up to dealing with that.
The explosion in contemporary design has meant that box gutters and rainheads are now the norm in residential roof construction and our review of literally thousands of roofs across Victoria tells us that most of these roofs are not compliant when it comes to overflow provision.
Overflow provision is critical.
Australian Standards makes provision for the roof stormwater drainage system to be totally blocked (e.g. no you didn’t get time to clean your gutters or rainheads on the weekend) or else to be overwhelmed by the sheer volume of water and yet STILL NOT LEAK OR FLOOD INTERNALLY. However, without adequate overflow provision, the building will flood.
The whole concept of compliant overflow provision is that excess roof stormwater catchment is able to be discharged externally where it causes no harm to the building. In other words you should never experience internal flooding which affects your ceilings, floors or medical records!
Plumbing compliance has been overlooked in the new house development gold rush and few people have realised it – even the regulators of the built environment in Victoria, the VBA, who must have been asleep at the wheel when doing Audits. People are therefore paying good money for proper, compliant plumbing works but not getting it.
If your home has leaked or flooded internally during the few summer heavy rain events that we’ve had recently, then it’s extremely likely your roof plumbing is non-compliant. Your home and contents insurance will not address the underlying plumbing issues and might also deny your claim just for good measure. The next time it rains you should also expect a repeat performance. Einstein’s definition of Insanity comes to mind – “Doing the same thing over and over again and expecting different results.” In other words, keep constructing buildings without compliant overflow provision and then be surprised when these same buildings leak or flood during heavy rain events.
Don’t let your roof plumbing problems drive you insane!
Contact Metropolis Solutions for expert advice. We specialise in the assessment of plumbing defects, how to achieve plumbing compliance and also in the process of making a claim against the plumbers compulsory insurance to cover all of the costs involved.