What is Roof Sarking? Benefits of Roof Sarking Insulation | Cost of roof sarking Insulations
What is Roof Sarking? Benefits of Roof Sarking Insulation | Cost of Roof Sarking Insulations
What is Roof Sarking?
Roof sarking is a flexible laminated membrane for use under roofing for tiles for added protection to the roof’s structural components. It is a membrane that contains various materials, such as polystyrene, reflective foil or felt, depending upon the brand of it.
If it contains foil, though, it can reflect heat as well as perform its other functions. It is applied at the time of the roof installation prior to setting the tiles into place.
Sarking acts as a second, protective skin for the roof under the roofing tiles and helps prevent rain and other elements from penetrating into the sheathing and beyond.
Roof sarking can also be defined as the process of placing small pieces of wood on the eaves and ridge lines of a roof to reduce wind noise.
It may also be called “sarking” or “sapping”. Although primarily used to reduce noise, this technique can also be used to provide protection from water, snow, hail, ice, and overheating.
The practice originally comes from Europe but gained popularity in North America during the Industrial Revolution.
Later the use of tar paper reduced the need for such techniques in most regions. However, the technique has seen a recent resurgence in popularity due to the increased use of wood-based products in residential roofing.
The earliest use of sawn wood as an edge covering for roofs is uncertain. In Germany, overlapping siding was laid atop the rafters and tied with hand-split shingles.
The technique was later picked up by builder William Ware who published coverage of it in his American Carpenter & Joiner.
The oldest surviving roofs covered in sarking appear to date from the late 19th century. In 1882 the New York Times published an article in which sawn roof siding is mentioned as a new invention. By the early 1900s, the technique was common in the United States and Canada.
The technique was widely used on wood clapboard and shingle roofs before asphalt shingles became popular in North America. In Europe, lower-cost clapboard and fir roofs were then covered with sarking.
While sarking involves trimming a roof’s edges to decrease wind noise, it does not pose any of the hazards of other methods of reducing wind noise such as apron or “noisecladding”. The sarking’s main benefits are both aesthetic and practical.
Generally, roofs with a lower pitch are best for sawnings. However, the technique can also be applied to roofs with steep pitch if done properly.
Otherwise, the technique may be less effective in damp climates where the weather cannot be controlled or where wind speeds are higher than standard for sawnings.
Sarking is normally initiated with a “scarf” – an angle of about 4 to 6 degrees cut into the roof. The cut is made between two adjacent rafters using either a circular saw or handsaw.
One edge of the scarf is overlapped by the first piece of sarking, which is fitted using nails, screws, staples, or glue (depending on material). Another scarf is cut to match the first, and the sarking is repeated across the entire roof.
The technique can be done using any type of sawn wood, although fir shingle siding or hickory shingles are most commonly used
However, some experts recommend against using pine boards or other softwoods on a roof due to their tendency to rot even after several years in use.
The type of sawning and its size depends on factors such as roof pitch and the desired result.
Importance of Roof Sarking Insulation
Whether as reflective thermal insulation, a protective second skin against flaming embers in a bushfire area, or a method to regulate condensation, here are the primary benefits of a sarking solution:
- Roof sarking enhances performance and comfort by providing the following advantages:
- Protects your property from undetected mould development or, worse, ceiling discoloration or irreversible damage caused by storm-driven rain entering the roof cavity.
- Reduces draughts that blow dust into the roof space, which limits dust entering the home through gaps around downlights and vents.
- Enhances thermal performance by minimizing heat flow through the roof, resulting in a more energy-efficient and comfortable home
- Helps to reduce the possibility of condensation by allowing moisture to escape while preventing water from entering.
- It provides supplemental ember protection for the roof space.
Roof Sarking FAQs
1. What exactly is roof sarking?
Roof sarking is a thin, malleable sheet with an aluminum foil layer that sits beneath a roof’s tiles.
It’s tough and waterproof, and it adds an extra layer of insulation to the roof by reflecting up to 97 percent of the sun’s radiant heat.
If rain penetrates the tiles and reaches the sarking, the water is safely diverted into the roof gutters, preventing damage to the roof.
Aluminium is a material that naturally protects against hot and cold temperatures, assisting in the regulation of the temperature in the roof cavity.
What does roof sarking do?
Sarking is a malleable membrane that acts as a second skin for your roof tiles. It improves the efficiency of insulation and protects your valuables from storm-driven rain and dust, moisture, and bushfire ember attack.
Is roof sarking necessary?
Sarking protects your roof from bushfires and storms, functions as a dust barrier, improves roof cavity protection, and acts as a vapour barrier.
Although sarking is not strictly required, we strongly advise installation to prevent and avoid a wide range of potential problems for your home.
Roof sarking is highly recommended due to its numerous advantages. However, it is only required in particular cases.
What is the cost of roof sarking?
Expect to pay between $6 and $10 per square metre for sarking. Reflective sarking is one of the most affordable types of insulation, costing about $120 for a 60mX1350mm roll.
Concrete tiled roofing costs between $40 and $60 per square metre. Steel roofing costs between $50 and $70 per square metre.
What is the recommended roof conditions for roof sarking?
- Tiled residential roofs having rafters longer than 6 meters in length, regardless of pitch.
- Tiled roofs with less than a 20-degree pitch and rafters longer than 4.5 meters.
- Those homes that are in Fame Zones and have Bushfire threat must comply with sarking requirements.
What is the difference between roof sarking and underlay?
Roof sarking is used to prevent rain and moisture penetration; it’s usually applied over an existing or new roof.
Underlay, however, is a primary layer that goes on top of the underlayment membrane before shingles are installed.
What is the purpose of roof sarking?
The main purpose of roof sarking is to help prevent leaks by keeping water from building up and then running down, under the roof sheathing.
It is also used for thermal insulation. Apart from thermal insulation, it also acts as a barrier against draughts, dust, heat, fire embers (from a blaze), and rain.
How do I install sarking?
The sarking is essentially laid out in portions away from the roof’s eaves, with a tiny overlap between each layer.
However, the process is far more complicated than this. Thermal bridging, vapour barriers, ventilation, and air gaps are just a few of the factors to consider.
Because good insulation is essential for a property, it is strongly advised to hire roofing specialists for the work, as they will have the necessary skills to accomplish the job efficiently.
If you’re determined to install the insulation yourself, consult the government’s detailed guide.
Is roof sarking fireproof?
As long as it’s installed properly with appropriate materials, yes. Fire-retardant options are also available for roofs made of non-combustible materials such as stone or slate.
What are the benefits of roof sarking?
Roof sarking will protect the frame of your house from the weather during construction.
Sarking will protect your roof cavities from storm-driven rain and dust, increase its thermal efficiency, help it resist bushfire ember attack, and lessen the chance of damaging condensation after your home is finished.
Benefits of sarking are summarized below;
- It aids in the regulation of the temperature in the roof cavity, hence enhancing thermal performance.
- It shields your home from thunderstorms and rain.
- Mold cannot grow in the roof cavity since the moisture level has been lowered. This also decreases the possibility of termites becoming ravenous.
- It keeps dust out of the roof hollow.
- It shields the roof cavity from strong winds.
- Some varieties of sarking enable a small amount of vapour to pass through, reducing condensation and moisture buildup within the roof hollow.
- It shields a home from flying embers and provides fire safety.
Can you repair roof sarking?
Repairing the sarking on a roof can be don I f your sarking has a tear, making the insulation it provides will be less effective.
may be easily repaired with specialized tape, such as Enviroseal’s ProctorWrap tape.
Does roof sarking serve as insulations?
Sarking is a flexible membrane that acts as a second skin for your roof tiles. It improves the efficiency of the insulation and protects your valuables from storm-driven rain and dust, moisture, and bushfire ember attack.
Roof sarking uses a layer of wood on the roof and roof sheathing that holds it securely in place without the need for added insulation.
5. What is the right roof sarking type to choose?
There are three main types of roof sarking:
- Thermoseal is a flexible membrane made of a specially formulated polyurethane foam that has an integral high-temperature sealant to help provide fire resistance. It can be used with almost any type of underlayment, such as mineral felts, and also in conjunction with tile or metal tiles.
- Protekt is also a flexible membrane made of a specially formulated polyurethane foam, but it does not include the high-temperature sealant. It can be used with underlayments such as mineral felts and also in conjunction with tile or metal tiles.
- Fiberglass roof sarking is low in cost but higher in installation time and labor requirements. It can be used with underlayments including elastomeric coatings that are specifically designed for use with fiberglass sarking.