Replace/replace damaged board under old door

[Daliu]

During the renovation of our veranda (house built in the 1920s), we encountered older sealed windows and entrance. We currently have no opportunity to open and restore this.

To the question. Under the door, we noticed there is damaged wood in one spot. It feels dry but is noticeably rotten when probed with a finger.

Do you have any tips on how we should proceed with the repair and what we should look out for when examining the area more closely?

The plan is to place new surface layers on top of the existing ones you see in the pictures.

Best regards,

 

[Jonatan79]

Is it an outer wall?

 

[Daliu]

Is it an outer wall?

Yes, it is.

 

[Jonatan79]

Hmmm, you should cut away a part of the floor in front and replace (and maybe insulate) the part that has rotted and check to see if there is more loose and old material underneath. Otherwise, it could become a thermal bridge and cool down parts of the new floor.

 

[Daliu]

Hmmm, you should cut away part of the floor in front and replace (and maybe insulate) the part that has rotted and make sure there is nothing else loose and old underneath. Otherwise, it can create a thermal bridge and cool down parts of the new floor.

Thanks for the help.
I'll try to investigate tomorrow. Maybe I'll come back with pictures.