Garage Door insulation

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jonherries

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#321482 21-Aug-2025 07:36

Have a roller door and have seen online 2-4mm insulation plus a few youtube videos of installs so figure it is possible.

My google-fu fails me when I am looking in NZ for a supplier of this. It appears to be a foam sandwich type of product with adhesive holding it to the door.

Example:

https://www.insulationgaragedoor.com.au/roller-door-insulation-melbourne-vic/

When I have a look around at similar style products, labelled for other uses this comes up:

https://www.bunnings.co.nz/qep-2mm-11m2-laminate-floating-floor-underlay-silver_p6650148

It seems like this might do the job?

eracode

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#3405970 21-Aug-2025 08:15

I know nothing about this specific issue but my first query would be: what level of insulation can a 2-4mm layer provide?

A roller door would seem to be quite unsuited to retrofitting a meaningful - i.e. thick enough - insulation product.

As you intimated, the product from Bunnings is not an insulation product.

What are you trying to achieve?

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mentalinc

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#3405979 21-Aug-2025 09:37

Also interested in this, keen to understand how insulation can reduce heat/temp in garage from the sun shining on the metal door.

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Bung

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#3405981 21-Aug-2025 09:59

"We use Australian-made 5mm thick closed-cell foam insulation, with highly reflective foil surface on both sides ..."

I have a roll of the floor underlay that is only about 3mm thick and only has foil on one side. I guess they are using a contact glue so that would depend on how it reacts with the bare foam.

eracode

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#3405982 21-Aug-2025 10:10

Bung:

"We use Australian-made 5mm thick closed-cell foam insulation, with highly reflective foil surface on both sides ..."

I have a roll of the floor underlay that is only about 3mm thick and only has foil on one side. I guess they are using a contact glue so that would depend on how it reacts with the bare foam.

Yep I saw that but the OP specifically mentions 2-4mm products. It's not clear whether the 5mm Australian proprietary product is available - probably not.

Wondering what you mean by 'bare foam' here. The Aussie installer attaches their product to the bare metal of the door with aerosol adhesive. Hard to see how even a 5mm layer would be effective insulation.

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mortonman

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#3405985 21-Aug-2025 10:24

Is it a roller door or a sectional door? I would think you could only insulate a sectional door as it doesnt roll up rather slide back along the soffit.

eracode

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#3405986 21-Aug-2025 10:26

mortonman:

Is it a roller door or a sectional door? I would think you could only insulate a sectional door as it doesnt roll up rather slide back along the soffit.

OP says it is a roller door.

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jonherries

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#3406125 21-Aug-2025 14:01

I currently have a metal door which is 2.5x2m which isn't insulated at all (R0.12 - according to this).

In terms of thickness - 2-4mm is what I have seen in different places on the internet - there are different thickness underlays available and there appears to be trade offs (thicker = increased diameter of door + weight + insulation).

I realise it won't be like replacing the door with an insulated sectional door. In general, given the cost - the underlay is about $70, I think a marginal increase in R-value is probably worth it. This is really my question as well as my choices of insulating material and adhesion choices.

Bung

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#3406146 21-Aug-2025 15:23

Is the garage used for the car or something else? A suggestion elsewhere is to put a temporary screen in front of the door if it isn’t being used.

jonherries

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#3406309 21-Aug-2025 22:16

Used for a car. There is an insulated wall at the opposite end, through to an office, but this last couple of weeks has me wanting to hold a more constant temp in the garage as we are often in and out of there and facing south it seems to suck a lot of warmth out of the space.

Jon