--- title: What is Roof Sarking? | Tradify™ description: Roof sarking is the term used in Australia and New Zealand to describe a heat resistant, waterproof membrane. --- [Build Your Best Trade Business | Tradify™ ](https://www.tradifyhq.com/blog) # [What is Roof Sarking? | Tradify™](https://www.tradifyhq.com/blog/what-is-roof-sarking) Written by [Team Tradify](https://www.tradifyhq.com/blog/author/tradify-team) | Mar 5, 2025 3:40:58 AM Roof sarking is the term used in Australia and New Zealand to describe a type of heat resistant, waterproof membrane that's installed within a roof. It's a requirement for homes prone to bushfires or extreme weather, acting like a second skin by protecting the home from embers, dust, moisture and draughts.  For the best long-lasting support for your business, try Tradify free for 14 days.  Low on time? Skip ahead!  1. [Why do you need roof sarking?](https://www.tradifyhq.com/blog/what-is-roof-sarking?hs_amp=true#why-do-you-need-roof-sarking) 2. [What types of roofs need sarking?](https://www.tradifyhq.com/blog/what-is-roof-sarking?hs_amp=true#what-type-of-roof-need) 3. [Benefits of roof sarking](https://www.tradifyhq.com/blog/what-is-roof-sarking?hs_amp=true#benefots-of) 4. [Can you put sarking in an existing roof?](https://www.tradifyhq.com/blog/what-is-roof-sarking?hs_amp=true#can-you-put-sarking-existing-roof) 5. [How can you repair roof sarking?](https://www.tradifyhq.com/blog/what-is-roof-sarking?hs_amp=true#how-can-you-rpair) 6. [Roof sarking outside Australia](https://www.tradifyhq.com/blog/what-is-roof-sarking?hs_amp=true#outside-aus) 7. [Future-proofing your roofing business](https://www.tradifyhq.com/blog/what-is-roof-sarking?hs_amp=true#future-proof) ## 1. Why do you need roof sarking?  Roof sarking keeps rain and dust out of the roof cavity, improves a homes thermal performance, and helps avoid condensation issues that can lead to structural damage and health issues. For jobs in bushfire-prone areas, sarking is essential as adds an extra layer of defence against errant embers. It also plays a big role during construction, protecting the frame from exposure before the roof is fully installed. However, while sarking does provide some heat insulation, it’s not a replacement for insulation like glasswool or polyester batts.  ## 2. What types of roofs need sarking?  In Australia, the [National Construction Code (NCC)](https://ncc.abcb.gov.au/editions/2019-a1/ncc-2019-volume-two-amendment-1/part-35-roof-and-wall-cladding/part-352-roof-tiles) sets out the requirements for roof sarking. Overall, they boil down to the following requirements:  - Sarking will be required for any tiled roofs with pitches less than 18 degrees, regardless of rafter length. - For roof pitches between 18 and 22 degrees, sarking is mandated when rafter lengths exceed: - **18° to <20°**: Rafters over **4,500 mm** - **20° to <22°**: Rafters over **5,500 mm** - **Above 22°**: Rafters over **6,000 mm** - In bushfire-prone regions, sarking is requierd in order to **reduce the risk of fires. ** For more details, check out the [NCC’s full guidelines on roof cladding](https://ncc.abcb.gov.au/editions/2016/ncc-2016-volume-two/part-35-roof-and-wall-cladding/part-351-roof-cladding). While the [New Zealand Building Code (NZBC)](https://www.building.govt.nz/assets/Uploads/building-code-compliance/e-moisture/e2-external-moisture/asvm/e2-external-moisture-amendment-5.pdf) does not legally require roof sarking, it does set out rules regarding **weather tightness and insulation** based on factors such as **wind zones, roof pitch, and roofing materials**. In these cases, roof sarking is usually the most cost effective way to meet these requirements.  For more information, refer to the [NZBC’s External Moisture Clause](https://www.building.govt.nz/assets/Uploads/building-code-compliance/e-moisture/e2-external-moisture/asvm/e2-external-moisture-amendment-5.pdf). ### **Tiled roofs** Adding sarking under concrete or terracotta tiles boosts weather protection by blocking wind-driven rain and preventing tile uplift in strong winds. It also cuts down on condensation, improves insulation, and is essential for ember protection in bushfire-prone areas. In many cases, the [National Construction Code (NCC)](https://ncc.abcb.gov.au/) requires it—especially for high-wind zones, bushfire areas, or steep-pitch roofs. ### **Metal roofs** For metal roofs, sarking helps to prevent condensation building up, protects against water damage, and keeps the place cool by reflecting heat. It also reduces noise from rain and hail by providing an extra layer between the roof and the main home. While not legally required, it’s strongly recommended in humid areas and often needed to meet energy efficiency standards. ### **Slate roofs** While it’s not always mandatory, installing roof sarking to slate roofs adds an extra layer of protection that can extend the life of a roof by keeping moisture out, reducing condensation, and improving insulation. ### **Shingle roofs** For any kind of shingle roof, asphalt, composite, or timber, sarking acts as a defence against leaks, improves wind resistance, and helps keep indoor temperatures stable. Providing some type of additional protective layer to shingle roofs is standard practice  across the U.S. and Canada, yet hasn't been made a legal requirement in Australia and New Zealand (yet). ### **Flat and low-slope roofs** Flat and low-slope roofs usually rely on waterproof membranes like torch-on bitumen, TPO, or EPDM instead of sarking. In these cases, vapour barriers or insulated roof panels do a better job of managing moisture and heat. ## 3. Benefits of roof sarking ### Improves thermal performance Properly installed, sarking can reflect up to a whopping **97% of radiant heat** when installed with an air gap. This can **reduce HVAC costs by up to 45%!** ### **Reduces condensation risks** Vapour-permeable sarking prevents costly and unhealthy. condensation buildup by allowing moisture to escape — while blocking external water ingress. This is critical in** regions **where condensation can lead to rot, insulation failure, and metal corrosion. ### **Controls moisture and prevents mould** Without proper moisture control, water trapped within a roof cavity can cause **mould growth within 24-48 hours**. Sarking acts as a moisture barrier, reducing the risk of health issues and structural damage due to timber rot or plasterboard swelling. ### **Acts as a wind and dust barrier** High winds can drive dust and debris into roof cavities, especially in **rural and bushfire-prone areas**. Sarking helps prevent up to **30% of airborne dust** from entering, which improves air quality and protects the ceilings insulation. ### **Provides sound insulation** Adding sarking can **reduce rain and hail noise by up to 50%**, depending on the roofing material. This makes a significant difference for metal roofs, which typically amplify sound more than tiled or slate roofs. ### **Protects the home during construction** Before the roof is fully installed, exposed frames are vulnerable to **rain, dust, and UV damage**. Sarking acts as a temporary protective layer, reducing potential weather-related delays, destruction or issues. ### **Fire protection** For homes in **bushfire-prone zones (BAL 12.5 to BAL 40)**, sarking is legally required under [Australian Standard 3959](https://www.saiglobal.com/PDFTemp/Previews/OSH/as/as3000/3900/3959-2009.pdf) to prevent ember attack. As o**ver 85% of homes lost in bushfires are due to embers rather than direct flame exposure**, it's no wonder why sarking has become an essential step. ## 4. Can you put sarking in an existing roof? You may be able to install sarking in an existing roof during major renovations or home extensions. For example, if you're re-tiling a roof, this provides the perfect opportunity to add sarking before laying the new tiles.   If no major renovations are planned, some sarking products can be cut to size and stapled between the roof rafters from within the ceiling space.   ## 5. How can you repair roof sarking? Damaged sarking can often be repaired using specialised tapes, but it’s essential to fix any holes or tears as fast as possible, as even small gaps can allow in dust, moisture, and draughts. ## 6. Roof sarking outside Australia Although roof sarking itself may not be a **universal** requirement, similar materials such as **roofing underlayment, vapour barriers, and waterproof membranes** are often mandatory in many countries.  ### **New Zealand** Roof sarking is common, but is **not always mandatory** under the [New Zealand Building Code (NZBC)](https://www.building.govt.nz/assets/Uploads/building-code-compliance/e-moisture/e2-external-moisture/asvm/e2-external-moisture-amendment-5.pdf). However, it is widely **recommended** for additional weatherproofing, insulation, and condensation control and is expected in **high wind zones** and **regions prone to heavy rainfall.** ### **United States** The term **"roof sarking"** is not commonly used in the **United States**. [Building codes](https://codes.iccsafe.org/) vary by state, but some type of underlayment is typically **mandatory** beneath **asphalt shingles, metal roofing, and tiles**. For **hurricane-prone areas** like **Florida and Texas**, building regulations require some form of **high-strength underlayment** in order to withstand extreme wind and heavy rainfall. ### **United Kingdom** [UK Building Regulations](https://www.gov.uk/building-regulations-approval) require **roofing underlay** or **breather membranes** in **most building in order to **help **prevent wind-driven rain, condensation issues, and moisture damage.** ## **7. Future-proofing your roofing business** Building the future of your roofing business can be time-consuming. A **job management system** like [Tradify](https://www.tradifyhq.com/) helps by: - **Automating scheduling & dispatch** – Assign jobs and track staff with [job scheduling](https://www.tradifyhq.com/features/scheduling-software)**. ** - **Tracking job progress in real-time** – Stay on top of jobs with [**job tracking**](https://www.tradifyhq.com/uk/features/job-tracking-software). - **Simplifying quoting & invoicing** – Generate professional quotes using [quoting software](https://www.tradifyhq.com/features/quoting-software) and invoices via [invoicing software.](https://www.tradifyhq.com/features/invoicing-software) - **Keeping everything organised** – Store customer details, job history, and paperwork with [customer and enquiry management](https://www.tradifyhq.com/uk/features/customer-enquiry-software). ### Get started! Using the right tools will save you time and make running your business easier. [Try Tradify for free](https://go.tradifyhq.com/signup) or [join a free demo](https://www.tradifyhq.com/book-a-demo) to see how it can streamline your operations. 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