What is Sarking on a Slate Roof and Why is it Installed?

Sarking, or insulation foil, is a flexible plastic sheeting with foil laminate applied to one side. It is applied on top of the rafters and under the battens the slate tiles are mounted to.

Sarking has several benefits which include:

  • Provides good weather protection during the installation of slate tiles
  • Prevents dust from entering your ceiling cavity
  • Creates additional insulating to your ceiling batts
  • Offers temporary weather proofing if your roof slates get damaged

A Byproduct of Space Program Technology

Outer space is much more brutal than Melbourne weather. Interestingly, though the benefits of foil insulation were well known decades ago as the result of the space program, only more recently have those benefits been applied to home insulation technology.

Foil insulation provides a “radiant barrier” that works equally well to retain heat in your home during cold weather and inhibit solar radiation (heat) from entering during hot weather. Heat transfer is accomplished through the infrared spectrum and foil thwarts that transfer so effectively that it’s used in outer space.

The conventional batt insulation in your home only slows down this transfer and becomes a radiant sponge in the process—soaking up heat only to leach it toward the cold. A little known law of temperature exchange is that heat seeks out cold. Summer heat seeks out the cooler air in your home. In the winter, cold is not actually coming in, heat is going out.

Understanding this nature of temperature exchange will help you realize why your home heats up noticeably at the end of a summer day and into the evening. Once your batt insulation is overwhelmed with stored heat from the day, it begins radiating it inward toward your cooler living space.

Foil inhibits this process by bouncing the heat back toward its source, therefore keeping you cooler in the summer and warmer in the winter, all while reducing energy bills. You may not think of a new slate roof as being a means of reducing energy bills, but because we use sarking on all slate roofing projects, you’re getting this additional benefit too.

Slate Roofing Durability in Coastal Areas

The question often comes up about how well slate roofing holds up against the effects of coastal conditions like salt air, high winds, brutal winters, and other demands that nature throws at the roofs located in the coastal areas of Melbourne. The answer is divided into two seemingly paradoxical replies:

Slate roofing holds up exceptionally well against anything coastal conditions can throw at it, and, slate roofing can fail miserably when exposed to the ravages of salt air and other coastal conditions.

How can both be true?

Though they seem to contradict each other, the answer isn’t likely to surprise you when you have life experience. It all comes down to the quality of slate roofing materials used and skilled workmanship just like so many other things in life.

On the downside, salt air in coastal areas is a major catalyst for promoting rust. Nails used to secure slate roofing tiles to your roof can serve as a source for rust. Rust inevitably degrades the slate roofing and leads to delamination, cracking and/or breaking, leakage, and even dislodging of the slate tiles. High winds typical in coastal areas can turn slate roofing tiles into dangerous projectiles causing additional property damage or even personal injury.

How quickly can this failure occur?

As little as 3-4 years!

Yes, that sounds scary, and it should. But the good news is, there’s no better solution for roofing that endures the ravages of nature in coastal areas than slate roofing. Properly installed slate roofing tiles that are lab tested to assure strict quality standards for water and salt air resistance will protect your home or building for decades—typically 15 decades or longer!

Having a “master slater” doing your roof is vitally important. Due to the short life and premature failure, even potential danger of cheap slate roofing, it is no bargain. For a modest price difference, a proven professional will provide a roof that withstands the coastal conditions of Melbourne not just for your life, but your children’s and even grand children’s and great grand children’s.

Creating a Legacy Together

When you’re looking for a new slate roof, it’s much more than just a new slate roof. Those who would try to sell you on just price are doing you a serious disservice. They actually fail to recognize the value of what they are supposed to be providing you with. That’s truly a shame for both you and them.

In reality, your new slate roof is the birth of a legacy that will outlive you, the architect, the builder, and the slate roofer. We often work with all four when doing a slate roof and it’s great to work with people who understand they are creating something future generations will still be able to enjoy.

Perhaps you’ve never really thought about it in that light before. In the process of managing our hectic lives, and the need for a new slate roof enters into your life, it’s easy to forget that the choice you make in getting that roofing done has such enduring value. But at least now you know that we’re thinking about that when we’re doing your new slate roof.

New Slate Roofing Services in Melbourne

Slate roofing is the long standing roofing material of choice in and around the Melbourne area. With a life span of up to 150 years even in this climate, combined with the aesthetics and choices of colors, textures, and material grades, it’s easy to see why.

With over 35 years in the slate roofing trade, we’ve found most people are surprised by some of the characteristics and diversity of natural slate roofing. For example, purple slate? Yes, some slate is purple. Slate is comprised of minerals and therefore naturally occurs in many colors. Given the prevalence of grays most common for slate roofs, the degree of color choices actually available is typically met with fascination.

More Interesting Advantages to Slate Roofing

Graceful Aging

We already mentioned the surprising array of color choices which also include blacks, greens, reds, and more, but because the colors in slate are provided by naturally occurring minerals in the slate and run throughout the thickness of the slate tile, color fading is minimal or non existent and actually adds to the appearance as it does occur.

Every slate roof is unique and takes on additional artistic style as it ages. An experienced slate roofer can guide you in creating a new slate roof that expresses your personality and fits the architectural style of your home or building. Then, as it ages, it even improves its appearance over time.


The Melbourne area is particularly brutal on roofing which is why slate outshines all other roofing materials. The key is in the “grade” of the slate used. High quality slate tiles are impervious to water penetration. They endure salt air with unrelenting stamina. Properly installed, even the harshest winds cannot dislodge them from their secure position on your roof.

Basically, to beat slate roofing, you’d pretty much have to move underground, where, ironically, you’d probably be under layer of slate.


There’s just something innately beautiful about a slate roof. Add the graceful aging and unparalleled weather protection and it’s in a league of perfection that life just doesn’t offer in large quantities. It looks good on new structures as well as “old” and “period” ones.

The size and shape, color, and texture of the slate tiles can be artfully implemented to compliment home or building.


It seems an exaggerated boast to say one choice of material for your new roof could be so superior to everything else, but slate roofing has earned that distinction. It ought to be self evident that only proven slate quality and experienced master slaters are capable of providing all these benefits, but you’ll want to be sure both are combined when contracting your new slate roof.