Our builder told us that, because we are using "Terracotta" roof tile, we need to install "Sarking" and "Anti Ponding Board". This post is to talk about what I found about these 2 Jargons...
What is Sarking?
I found this definition of "Sarking" from the internet: "Sarking is a reflective foil laminate that is installed inside roofs. It has many benefits including weather proofing, insulation and reduction of dust and sound". The image below shows what it looks like:
The drawing below is from this page on greenhouse.gov.au, it clearly shows how the sarking are installed under the roof tiles. "RFL" stands for "reflective foil laminate".
The next image shows how sarking been installed: start from the bottom, with some overlapping when installing the second one. This is to ensure that if there's any water, it flows down to the gutter.
What is Anti Ponding Board?
So "sarking" is not that hard to understand, it took me a while to work out what is "Anti Ponding Board" used for.
The most simple and easy to understand explanation I found is from harmonyrooftiles.com.au: "The boards are installed to support sarking and ensure that any water collected by the sarking is correctly discharged into the eaves gutters."
The drawing below is also from the same page mentioned above from harmonyrooftiles.com.au:
The drawing below is from this page on bristileroofing.com.au.
So this "Anti-Ponding Board" thing is installed at the edge of the roof, and under the sarking to allow waters collected by the sarking to discharge into the gutter.
I remembered one of the Clarendon sales strongly recommend not to install sarking. Her reason is, if there's a crack somewhere in the tiles, it will be very difficult to work out which is the cracked tile. Because the water will run all the way to the gutter because of the sarking... Hang on, what are you talking about? That's one of the main reasons for installing sarking: to prevent leaking water from damaging my roof/ceiling! I would certainly prefer to have this extra protection than water damaged roof/ceiling!