Insulating steel door in the basement afterwards

I am trying to improve the insulation of my house and have come across a thermal bridge in the basement. The steel door to the outside stairs has no insulation at all. Buying a new one is not an option for me. Now I am considering simply sticking a thick layer of Styrodur onto the door. I still have leftovers of it. What do you think about this somewhat unorthodox idea? Will it work or could it possibly cause damage?

Hi Jupp,

have a look around for a used steel door with insulation, they don’t cost a fortune. In my opinion, most of the heat is lost through drafts with these old steel doors. I would rather try to make the door absolutely airtight than insulate it additionally. Buy a good door seal at the hardware store and especially pay attention to the sealing at the bottom, as there it often drafts a lot.

Hello Jupp, Kneerim is right, the sealing of the joints and towards the floor is important. I cannot say whether the insulation of the door leaf is beneficial. The insulation will certainly bring some improvement, but as I said, I cannot determine the extent of the improvement.

Ok, thank you, I have for now only improved the sealing. The wind really blew through there powerfully :-)

Hello,

I actually wanted to implement it that way too and came across these posts. My idea was to insulate it with Styrodur, but the problem is the joints and the bottom edge of the steel door.

Are there any other ideas?

It is better here, as already suggested, to buy a new or used steel door. They are not that expensive. Then the problem with the insulation is solved. That is much better than tinkering around here.