If you’re wondering what roof sarking is, you’re in the right place. Follow our guide to find out what sarking is, why you need it in your home, and install it in your roof space.
What Is Roof Sarking?
During home construction, renovation projects or building a new home, roof sarking protects the building structure from the weather. After completing your projects, roof sarking has several functions: it acts as a dust barrier, protects your roof cavity from storm-driven rain, improves your home’s thermal performance, helps it resist damage from bush fire embers and reduces the risk of potential condensation problems in your roof space.
Roof sarking is a strong and pliable laminated membrane that sits under tile and metal roofs, protecting against moisture, drafts and dust. Sarking comprises a reflective foil layer on one or both sides that protects against radiation by reflecting heat from the sun’s rays away from your roof. It protects homes in warmer climates from summer heat flow by reducing the temperature inside the interior roof cavity, thus preventing radiant heat from being transferred throughout the house.
Is Roof Sarking the Same As Insulation?
Roof sarking is classified as insulation and works similarly to traditional roof insulation. During colder winter months, roof sarking helps to insulate your home and keep heat inside, whilst in hot summer months, it reflects the sun’s rays to help your home stay cool.
R-Value refers to how well insulation resists the flow of heat: roof sarking, when installed properly, helps increase the R-Value of your home. The higher the R-Value, the more effectively insulated your home is. When installed adjacent to air cavities in a roof space and combined with ceiling insulation, roof sarking enhances your home’s energy efficiency by preventing heat flow. Differing climates influence the level and the type of insulation, but overall, roof sarking has the potential to reduce greenhouse gas emissions and save you money on energy bills.
Do You Need Roof Sarking?
The Building Code of Australia (BCA) states it’s a mandatory requirement for roof sarking to be installed in all modern residential tile roofs with a rafter longer than six metres. However, it is considered good building practice to install roof sarking under all tiled roofs to protect homes by blocking external water from getting in and causing potential moisture damage in your roof cavity.
If you’re planning to build a new home or renovate your metal or tiled roof, you may have to install roof sarking depending on certain factors outlined by the Building Code of Australia, including:
- Living in a bushfire prone area
- Local wind speed
- Terrain category
- Roof pitch
It’s better to be safe than sorry, so always check the appropriate roof sarking guidelines. We recommend installing sarking no matter the type of house/roof you have and where you live, as roof sarking has several benefits!
Installing Roof Sarking
When your roof is off for renovation or home extensions, or before roof installation on a new build, roof sarking goes on to the building frame to protect the structure from the outside environment. You need to choose a sarking that meets the terms of the Australian building code (BCA) and one appropriate for the type of roof you have, whether metal or tile roof, as not all sarking is the same.
Roof sarking rolls out in sections away from the roof eaves, so professional installation is wise. You must consider various issues like thermal bridging, vapour barriers, ventilation, and air gaps. We recommend hiring a professional with good experience in roof sarking installation to ensure it protects your home.
Can You Install Sarking in an Existing Roof?
You can install roof sarking on existing residential roofs. Roof sarking is an important component of your roof system. It gives your home additional protection from water vapour and the sun’s radiant heat and reduces draughts, allowing insulation to do its job and saving you money on energy costs.
While we recommend professional installation, installing roof sarking on an existing roof is something you can do yourself. If you do want to install roof sarking yourself, it’s important to consider the following:
- Sagging your sarking sheets is vital to ensure proper drainage with the gutter and proper roof insulation.
- You must create an air space between the roof membrane and the underneath part of the roof sheet to develop a drying path.
- Tape down the vertical overlap amidst the roll joins, ensuring you’ve sealed the side laps to block any water spilling within the roof cavity.
How Much Does Roof Sarking Cost?
The price of roof sarking depends on the type you buy, how heavy duty it is, and the thermal rating. Costs generally range from $2 – $3 per square metre, and a 60 x 1.35-metre roll will usually cost between $180 and $300. This estimation does not include labour costs, which vary depending factors like on location, company and the size of your roof space.
Can You Repair Roof Sarking?
Roof sarking’s aluminium foil lining can sometimes become torn or ripped, and fixing holes or tears in the material is crucial for ensuring your roof sarking works properly as that vital protective second skin. Holes in roof sarking can let in dust, moisture and draughts, reducing the thermal performance and potentially making a mess in your ceiling space!
Benefits of Roof Sarking
Now we know more about roof sarking, let’s look into an overview of the benefits.
- Protects your building structure – roof sarking prevents wind-driven rain and dust and other weather conditions from causing water damage to the internal structure.
- Improves on-site efficiency – roof sarking allows internal trades to work before in all conditions before roof installation.
- Improved thermal performance – roof sarking shields from radiant heat to provide a more energy-efficient and comfortable home.
- Reduces the risk of condensation – vapour-permeable roof sarking allows water vapour to safely and effectively drain away from your roof space.
- Protects from unseen mould growth – sarking minimises the risk of problems like mould, ceiling staining or permanent damage by blocking the entry of storm-driven rain into the roof cavity.
- Limits dust entering the home – roof sarking reduces draughts that blow dust into your roof space.
- Bushfire protection – in bushfire-prone areas, sarking helps to protect against damage from fire embers.
Roof Sarking Wrapped Up
Roof sarking offers crucial protection from the elements during renovation or construction and is often a requirement for residential roofs in Australia. Combined with other essential roofing components like insulation and flashings, it improves thermal performance and offers effective fire protection and several other benefits for your roof and home.
Problems occasionally arise, but another benefit is that sarking is easy to repair if any rips or tears occur. Roof sarking is a more than worthwhile addition to your home!