R-value of a basic garage door?

Same as a shed with walls done that way.

That doesn't help me find what it is, everyone is talking on the web about insulated sheds. Nobody ever mentions what R is for an uninsulated one. I know a house brick is 0.8. Is steel worse than that? A lot worse?

Well for a 1 mm plain steel sheet (which might be a bit thick) the U will be about 43000 W/m^2K so the R will be 2.3*10^-5 m^2K/W.

A coat of paint or perhaps a plastic coating will make quite a bit of difference.

There must be some data about uninsulated sheds, if only so you can see what result you will get if you insulate one or don't bother.

Bet the tables of R values for walls do.

Yes, much worse. Not much better than nothing with R values, tho it obviously does stop the wind blowing thru particularly when you are heating the shed.

You wouldn't be far out if you assume 0.

That is close to what single glazed glass is.

I looked but found only insulated sheds.

I've only ever found brick, air gaps, glass, and insulation.

It's now been removed, I've got a single brick wall with poly sheet insulation and wood cladding, with a double glazed window in it.

Yes, but that is what a sheet of metal is, no insulation at all.

Only because it lets the air blow thru. The thin layer of air that the sheet of metal replaces does in fact CONDUCT less than the sheet of metal does.

I guess nothing would be less than R=0, as you have more than just conduction, but free flow of air.

Indeed, which is why the R in reality of the garage door is more than the sheet of steel alone.

almost nonexistent.

I used to have to work in an uninsulated sheet steel and plexiglass cabin ( not a shipping container, a lot less substantial) and the blow heater going full blast just about kept it warm. Turn the heater off and the temp plumm eted within minutes. No insulative effect at all, it just kept the wind out .

Steel garage doors are usually very badly fitting too, so lots of draughts.

Owain

I had fitted draught excluders, but I was unaware most of the heat went through the steel door. I insulated the ceiling first as heat rises.

Maybe there's a shortage of wood in Australia? Most sheds are wood in the UK.