Today’s metal roofs aren’t just a layer of metal sheeting – rather, they use a system of different layers, all of which work together to keep the weather out and ensure that your home is comfortable and secure for decades.
We’ve talked about sarking and insulation before. However, there’s another layer to your new metal roof that’s also essential for a strong house foundation and structure.
Underlayments are essential – they’re also frequently overlooked by homeowners.
Roof underlayments are a part of metal roofing installation in Melbourne that doesn’t often get a lot of air time. In fact, oftentimes they’re barely ever mentioned!
Underlayments are an essential part of tiled roofs – but what if you’ve decided on metal?
First thing’s first: what’s an underlayer in your metal roof?
Underlayers are just that: layers that sit immediately under your roof itself, installed immediately before the rest of your roof.
While underlayers serve many different purposes, the main ones are:
To stop water getting in
While this is more of an issue for tiled roofs, it’s something you’ll want to think about during metal roofing installation as well.
To help with insulation
While metal roofing is more thermally efficient than most give it credit for, it’s inevitable that some summer heat will radiate through the metal into your home.
Certain underlayers (specifically, sarking) can reduce this, making your home more comfortable.
While this is a bigger concern for tiled roofs, it affects metal roofs as well. Essentially, an underlayer provides a backing for your roof, reducing the odds of buckling.
The difference between underlayment and sarking
Search for the difference online, and you might notice that a lot of websites say that sarking and underlayments are one and the same.
Those sites would be wrong!
Over in the United States, sarking is used as a catch-all term for all types of underlayments. But that’s not the case here.
In Australia, sarking specifically refers to a specific type of underlayment – specifically, it refers to an aluminium foil layer.
While other types of underlayment are available in Australia, we’ve noticed that sarking is the most suitable for Australian weather conditions, owing to its:
- Reflective properties
- Ability to form a more effective vapour barrier
- Ember-resistant properties
- Ability to help moisture escape from your roof
Of course, Australia is a big continent.
While most metal roof installations in Melbourne are best off with sarking, there are some parts of the country where an alternative underlayer may be more appropriate.
If we’re talking about alternative underlayers to sarking, synthetic underlayment is the most common choice for metal roofing installation in Melbourne.
Typically made of polyethylene or polypropylene, synthetic underlayers offer a range of different benefits depending on the exact composition and brand chosen.
As a general rule, however, synthetics:
- Are lighter – something that has implications for roof integrity
- Come in larger rolls, which can help with installation
- Are better at reflecting away heat
While more popular in tiled roof installation, there are nonetheless plenty of metal roofs out there with synthetic underlay as an alternative to sarking.
The traditional choice felt underlay is losing ground to alternatives like synthetics or sarking.
Of course, look hard enough and you can still find it here and there.
Made using polyester or fiberglass blankets soaked in a waterproofing agent, felt underlayments offer a more affordable option to sarking and synthetic underlays.
Of course, the trade-off is a heavier weight and reduced performance – little wonder that this type of underlayment is scarce in new construction nowadays.
Which type of underlayer is right for your metal roofing installation?
Specifically, it depends on your local weather conditions. That means variables such as:
Additionally, it also depends on your needs.
For example, if your property needs even greater insulation than sarking can offer, we might start looking at alternative underlayers to give you the protection you need.
As a general rule, however, the vast majority of metal roofing installations in Melbourne are best served with sarking. While our city has a reputation for wild weather, most of the time, the climate is mild enough that you don’t need to spring for a more specialised underlayer.
Our metal roofing team in Melbourne begins each job by taking stock.
We inspect the site and plan, as well as local conditions – this allows us to choose the best components for your roof, including:
- The right gauge and brand of metal roofing
- The best type of metal roofing
- How it should be attached to your property
And of course, that also includes the most suitable type of underlayer too!
Get the right underlayment for your metal roofing installation in Melbourne
Before your metal roofing installation begins, it’s important that you lay the foundation first.
In addition to choosing a suitable underlayer, that also means good planning, consulting with a structural engineer and obtaining permits.
Our metal roofing team doesn’t just bring our Masterful workmanship and skill to your metal roofing installation in Melbourne – we can also help with each of these steps.
We’re committed to giving your home a roof that is:
- Strong and durable
Want all three of these things for your home? All it takes is a phone call to Watermaster Roofing!