Window flashing
Hi everyone , i wrote 2 weeks ago regarding a question a had about te way you guys sheaths your house with ply . I got a very satisfactory answer on the subject but didnt get anything about window flashing and wanted to creat that topic to ask your opinion on that particular topic . I have posted below a 3 video link to a big store DIY video showing how to install windowsand the australian windows association . In all it is how i see windows install everywhere in australia , i had mentioned never seeing peel and stick flashing here but the only flashing used is that black plastic that is stapled .
After reading for so long about the way windows are flashed on this web site or by people like Matt risinger , ns builder , bsc , pro trade craft i just cant understand how these flashing technique do anything at keeping water out .
On the video about aluminium windows with it “in built flashing details ” i dont understand how the water isnt going to come in between the window and the window opening , and as for the wooden casing window with the stapled flashing i dont see how the staple provide a sealed attached or why the water wouldnt go under the flashing in the joint with the window frame .
With the window association video , the flashing at the jamb is just stapled and the edge is just left alone ( third link 4:oo min ) ( as if water couldnt find a way under ? )
am sorry if that seems all silly but i have been reading for 2 years quit intensely on your website and many other and do not umderstand the logic of window install in australia and why we do not come accross massive failure as i understand these flashing to not do anything at stoping water intrusion . i may be missing something and would like to be shown what .
Thank you all
https://www.bunnings.com.au/diy-advice/home-improvement/windows/how-to-install-aluminium-windows
https://www.bunnings.com.au/diy-advice/home-improvement/windows/how-to-install-a-casement-window
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Replies
Kevin,
Construction practices in Australia appear to be similar to construction practices in the U.S. in the 1960s.
New Zealand experienced a wave of construction defect litigation and water-entry problems about 16 years ago. I reported on these issues in an article for Energy Design Update. Here is the link: "Leaky Homes Plague New Zealand." (The article is attached below.)
There are two reasons that Australian builders have gotten away with sloppy window flashing practices: (1) low rainfall rates and (2) wide roof overhangs.
For information on best practices, see this video series: "Window Sills That Won’t Rot."
Evidently they aren't concerned about air sealing. But all air barriers (eg, drywall and exterior sheathing) need an airtight connection to the window.
Kevin,
Coincidentally, I had lunch yesterday with a friend who just returned from visiting family in Australia for a month. She was astonished by how poorly the houses were built, having baked in the current heatwave, and on her last visit frozen during a quite mild winter. Just as your concerns illustrate, her main comment was on how drafty the buildings are. Judging from the links you posted, the problems are endemic to the industry there, and it might be quite difficult to build a well performing house if the resources to do so aren't readily available.
Thank you three gentleman for your time to look at my question and answer it .
Thanks martin for the pdf on the new zealand affair i had hear of it but not read something that detailed about it .
Jon R i had mentioned earlier that indeed air tightness isnt a concerned here , the term itself and its impact on Buildings is totally unknown . The building code of australia requires no airtightness minimum regardless of the climate zone which goes from hot humid up north to alpine in tassie and the flashing requirement are as minimum as can be like shown on the 2016 window of australia association .
Malcolm , your friend is right and the conditions of living here although not unbearable are at time highly uncorfortable . I have started this year my journey of studying architecture and wish to one day become on architect/builder and bring to australia the practises that are discussed on this website an others to the people of australia .
Energy conservation is for me a real motivation and the confort of leaving in high performance home will i hope be attractive to the australian the same way as it is in america and europe .
Once more thank you for the time taken to answer me and thanks to this website for allowing me to ask these questions and all of the highly informative content on it . Its a real bliss to be able to educate my self through the sharing of your website .