Thermalite plantation shutters, explained
What the material is, how it compares to timber and PVC, and why we have made shutters from it in Brisbane since 1985.
Most plantation shutters sold in Australia are made from timber or PVC. We make ours from Thermalite, and we get asked why often enough that it is worth setting out properly.
What Thermalite actually is
Thermalite is a dense, non-toxic polymer. It has the look and feel of wood, and none of wood’s weaknesses in a Queensland climate. It is water resistant, fire retardant, and provides over two to three times the insulation of timber or vinyl.
That combination is why it works in places timber shutters cannot go — bathrooms, kitchens, laundries, balconies, and anywhere on a western wall that takes the afternoon sun.
The material is made from non-toxic, recycled content, with patented paint finishes that are hypoallergenic and sit below acceptable VOC emission levels. Nothing harmful is emitted into the room.
Timber, PVC or Thermalite?
All three make a plantation shutter. They do not all last the same way.
| Timber | PVC | Thermalite | |
|---|---|---|---|
| Warping and shrinking | Prone to it, especially in QLD heat. Can pull shutters off hinges | Less rigid, smaller blade spans | Will not warp, crack or shrink |
| Water | Takes on moisture, affecting strength and finish | Water resistant | Water resistant — suits wet areas |
| Insulation | Lower than PVC, aluminium or Thermalite | Moderate | 2–3× timber and vinyl |
| Finish over time | Fades in sun, needs repainting | Can yellow | Will not yellow. 3-year paint guarantee |
| Panel size | Varies with timber quality | Smaller spans — limits external use | Suits long and wide panels, internal or external |
| Environment | Deforestation in production | Uses potentially harmful plastics | Non-toxic, recycled content, low VOC |
If you are quoting timber, ask what species it is and where it was made, and be wary of cheap timber composites that decay. If you are quoting PVC, ask about the maximum panel width before it needs a divider.
Why it insulates
Glass is a poor insulator. It lets heat out in winter and traps it in summer, which is why a west-facing room is unbearable by three in the afternoon.
A plantation shutter closes tight to the window frame and creates an air barrier. Blinds and shades do not — air escapes around the edges even when they are closed, and lightweight fabrics lose heat readily. A sealed shutter holds the barrier.
Pair that with a material that insulates two to three times better than timber and you get the best of both. Thermalite blocks excessive heat while still letting you open the louvres for airflow, and you can adjust how much light and heat comes in as the season changes.
It works in both directions: heat kept out in summer, warmth kept in through winter.
Sizes, styles and finishes
Every shutter is made to the opening, so the shape of the window is not a constraint.
Four opening styles
Fixed, hinged, sliding and bi-fold — including Shutter Style™ barn doors on a sliding track.
Louvres 64 to 90 mm
Elliptical louvres in a range of widths. Wider louvres give a cleaner view out; narrower suits smaller windows.
A finish that stays put
Guaranteed for 3 years not to crack, peel or yellow — and it keeps looking right well beyond that.
Made here, in about three weeks
Every Thermalite shutter is made at our factory at Seventeen Mile Rocks in Brisbane, by local tradespeople, and has been since 1985. Nothing is imported and finished here — it is made here.
That shows up in the lead time. 15 to 20 business days, around three working weeks, which we guarantee in writing. Overseas manufacture routinely takes three times as long, with no ability to inspect what turns up.
It also shows up when something needs fixing. The people who made your shutters are twenty minutes down the road.
The warranty
Thermalite frames and panels carry a 25-year warranty that transfers with the house, subject to approval and a site inspection. Hardware is covered for 5 years and the paint finish for 3.
Monthly cleaning is a condition of the warranty, and stainless steel hinges are mandatory in coastal areas. Both are set out in full on our warranties page and product care.
Free in-home measure and quote
Brisbane and the Gold Coast. No obligation, and we do the measuring.