A Perth summer is hard on an outdoor room. Under a standard single-skin steel roof, the sun heats the sheet and that heat radiates straight down onto your table and chairs. Stratco Cooldek panels are made to stop that. Here is how they work, what the numbers say, and when they are worth choosing for a Western Australian patio.
What is Stratco Cooldek?
Cooldek is an insulated roofing panel made by Stratco. It is a sandwich: a profiled, colour-coated steel sheet on top, a core of expanded polystyrene (EPS) insulation in the middle, and a flat steel sheet underneath. The three layers are bonded into one panel.
According to Stratco’s published specifications, the top skin is 0.42mm steel and the underside is 0.60mm steel. The core comes in 50mm, 75mm and 100mm thicknesses for most patios, and up to 150mm for larger or commercial jobs. Panels cover 1000mm in width and span long distances between supports, so a large patio often needs fewer beams.
Why it keeps the space cooler
Heat moves from hot to cold. On a hot day the top steel sheet heats up in the sun. In a single-skin roof, nothing stops that heat from radiating down into the patio. In a Cooldek panel, the EPS core sits between the hot top sheet and the underside, and it slows that heat transfer a great deal.
The standard way to measure this is the R-value. A higher number means more resistance to heat flow. Stratco’s published figures for the Cooldek CGI profile are:
| Panel thickness | R-value (CGI profile) |
|---|---|
| 50mm | R1.42 |
| 75mm | R2.16 |
| 100mm | R2.77 |
A single sheet of steel adds almost nothing. If your patio sits against a west-facing wall or catches the afternoon sun, moving to a thicker panel is usually the best upgrade you can make.
More benefits than heat
- Less condensation. Single-skin roofs can drip when warm, humid air meets a cool sheet. An insulated panel resists this, which protects your furniture and any lighting.
- Quieter in the rain. The insulating core reduces the drumming of heavy rain on the roof.
- A finished ceiling. The smooth underside looks like a ceiling, and a built-in rebate hides wiring for fans and lights.
- Warmer on cool evenings. The same insulation slows heat loss, so the space holds a more even temperature through the seasons.
- Fewer supports. The panels are stiff, so longer spans are possible and the structure can look cleaner.
Choosing your thickness and colour
For most Perth homes, 75mm is a sound middle choice and 100mm is worth considering for west-facing or exposed outdoor rooms. Stratco lists topside colours including Off White, Smooth Cream, Armour Grey, Gull Grey, Slate Grey, Merino, Mist Green and Banyan Brown. Lighter colours reflect more heat, and the underside can be white or a gloss colour.
The best choice depends on your site: which way the patio faces, how much shade is nearby, and how you use the space. We assess all of this at the free measure and quote.
Common questions
Does an insulated roof make a patio cool?
It makes it noticeably more comfortable by blocking much of the heat from the sun-baked roof. It will not air-condition the space, but combined with a ceiling fan and good airflow it makes summer afternoons far more usable.
Can I add insulation to any patio style?
Yes. Insulated roofing suits flat, skillion and gable designs. Roof pitch needs to meet the manufacturer’s minimum, and we handle that in the design.
Do I need a building permit?
Most patios need council approval. Plans and council paperwork are part of our service. See your local rules on our building permit page.
Get an insulated patio quote
We design, engineer, supply and install insulated patios across Perth and Western Australia, in full or kit form. See our insulated patios, then call 0420 361 450 or request a free measure and quote.
Specifications are from Stratco’s published Cooldek product information and design guide. Always confirm current details with your builder.