Warm roofs are becoming more popular in the Australian market, as more people learn that this style of roof insulation can provide better thermal performance.
The main difference between a warm roof and a cold roof is where the insulation is located.
As National Business Development Manager at Kingspan Insulation Jeremy Robb explains “a warm roof is where you actually keep the substrate warm, whether that be concrete, cross laminated timber or steel. What you’re doing is you’re insulating above the substrate”.
In a cold roof insulation system, the thermal insulation layer is positioned in the ceiling cavity between joists, below the structural deck.
National specification manager for Fatra Australia Ashley Bowen says warm roofs have been commonly used in other parts of the world like North America, the UK and Europe but now Australia is catching up.
“It is just about bringing our code up to more efficient standards. We've seen that over the last four or five years, we’ve improved our thermal performance, our section J standards, condensation control and mitigation,” Ashley said.
We are starting to follow the lead of European and American markets in construction and thermal performance. We are seeing a huge increase in proactively insulating our structures externally in the form of warm roofs”.
Jeremy explains warm roofs provide continuous insulation and can be used on a wide variety of substrates. They’re also easy to install and design and can be retrofitted onto existing rooftops and they allow for a vast array of finishes.
Kingspan offers warm roof systems such as the Kingspan Therma Board which is a PIR board made from a rigid set board with a compressive strength of 15 tonnes per square metres.
“That allows for a trafficable rooftop for maintenance purposes as well as allowing for things like a green roof, pods and pavers, solar equipment whatever it may be,” Jeremy says.
Warm roofs are popular in remedial spaces, particularly where there are older buildings that have issues with ponding or leaking on a flat roof.
“One of the systems we have is the taper board system where you can use tapered insulation boards to create a precise fall,” Jeremy says.
Another benefit of warm roofs is that they make homes more watertight.
“Water ingress and condensation is a real problem here in Australia,” Ashley says.
“That’s why we see a lot of the older buildings have issues of mould and condensation”.
Jeremy explains that cold roofs have an exposed substrate, so the actual dew point is on the underside of the slab.
“We need to keep that cavity extremely well ventilated because otherwise it will just accumulate and lead to mould issues,” he says.
“The warm roof takes dew point above the substrate so taking the risk of condensation forming in the habitable space away. That’s one of the main advantages of this system”.
Both Ashley and Jeremy agree that the most important thing to do when considering a roofing insulation system is to have a thorough consultation with an expert to ensure the solution is appropriate for the build.
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