Replace part of carpet

[SmoothCriminal]

I foolishly damaged a 3x4 area of my wall to wall carpet in my living room by washing it repeatedly and not letting it dry before I put a chair mat on it. I now think there is mould growing and various treatments I tried have not reduced the smell.

There is some leftover carpet that I found when I moved in. It's enough to fill in the area with a 10 inch margin all around.

Question: Is replacing part of a carpet like this recommended as opposed to doing the whole room. And what does the process entail?

 

[gregers]

i used to work with an old school carpet fitter,who used to hand stitch carpets back,seamlessly.
im in no doubt there is a modern day version using adhesive.
you will have to make sure the lay of the carpet is matched aswell as any pattern in it.