What an insulated garage door does
B&D NZ says its insulated sectional doors use a graphite-infused EPS insulator fitted in the factory, and that the doors also dampen sound. Dominator says the same kind of panel absorbs infrared energy and reflects heat, giving up to 20% better insulation than traditional EPS, with no CFCs or HCFCs.
That matters most when the garage shares a wall with the house, or doubles as a gym, an office or a sleepout. If the garage only ever holds the car, a standard door may be all you need.
Insulated doors the makers list
| Door | What it says about the insulation | |
|---|---|---|
| B&D NZ | Therma Tech II insulated sectional door | Graphite-infused EPS fitted in the factory, also dampens sound |
| Dominator | Insulated sectional door | Graphite-infused EPS, up to 20% better than traditional EPS |
| Garador | Insulated sectional door | Ask the door specialist for its figures |
R-values and garage doors
No New Zealand maker we read publishes an R-value for an insulated garage door. Dominator compares its panels with traditional EPS instead. If anyone quotes you an R-value, ask what door it was measured on and who tested it.
Insulating the door you already have
Retrofitting insulation has a catch. The extra weight changes the door's balance, so Dominator says the door has to be weighed and its springs changed to suit. Skip that step, it warns, and the opener wears out sooner and the safety reverse may not behave.
So talk to a door specialist before you buy a kit from the hardware store, and never try to rebalance the door yourself.
Insulated roller doors
The insulated doors Dominator and B&D NZ describe are sectional doors. If you would rather keep a roller door, ask the door specialist what is available for it, and be clear whether the job is a new door or insulating the one you have.
Good to mention when the door specialist calls
- How the garage is used, and whether it shares a wall with the house
- Whether it is a single or a double door
- Whether there is an opener, and its make and model
- Whether the job is a new door or the door you have now
- Whether the house is near the sea, which changes how often to wash the door
What we would do
Ask about the gaps as well as the panels. Heat and noise find their way round the edges, so have the door specialist look at the seals along the bottom and sides when they quote an insulated door.