Firedoor between house and garage - internal or external?

7 May 2011
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United Kingdom
I don't know much about doors, but I've been told I need a firedoor between the kitchen and the garage (we're making a new opening). However, the garage is a cold space, and we're upgrading the insulation in the wall between the house and garage. So if I put a standard firedoor in there, isn't that basically an interior door, and so won't provide very good thermal insulation? (Firedoors don't seem to have rated R values)

Would it be better to put an exterior door in there? I'm not sure if there is such a thing as an exterior firedoor though.

Also wondering about the sill. Presumably I don't need an exterior sill as these are mostly about keeping out the weather?

I probably will want a decent lock though - perhaps a standard deadbolt will be sufficient.
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"Exterior" refers to the ability to deal with the weather (ie rain) and not the ability to divide a warm and cold room

Any fire door will do, and will have comparable heatloss to any other exterior door
Oh, OK thanks.

I do wonder, though, why exterior doors tend to have a quoted U value, whereas interior ones don't. Look on the B&Q site, for example.
Because exterior doors , being part of the exterior, need to have a U value so as to ensure, or determine how well they prevent heatloss to the external air. Its all fairly recent, and part of saving the planet :rolleyes:

Internal doors don't need to stop any heat going from room to room in the same property, so are not rated
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But, as I said in the original question, this door *does* need to stop heat-loss between rooms. Because on the other side of the door is an uninsulated, cold garage. I.e. in winter it will zero degrees in the garage. That's why I was asking about 'external firedoors'.
And as I said in my original rely a fire door will have comparable heatloss to any other exterior door

If you think about this logically there is absolutely no need for an external fire door, so that is why they tend to be internal doors
Personally I would use a solid core door to the garage. Also called a 1 hour fire check. With betetr thermals too than a standard composit door.

Locking to the door to be the same as you would on a front door.

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