Rotten Floor Joist

[adam992]

Ripped out the old ensuite and one of the floor I-joists is partially rotted. It has dried out, the leak occured before we moved in 18 months ago. Top flange is soft about half way (1 cm) but not crumbling away, the web and bottom flange are ok.
I was going to add wood to the webbing to support a sunken floor for a curb less shower like the image. Would that be enough extra support or is there anything else I can do to support the damaged I-joist?

 

[jurassic sparkk]

You could sister the joist.

 

[blup]

Ripped out the old ensuite and one of the floor I-joists is partially rotted. It has dried out, the leak occured before we moved in 18 months ago. Top flange is soft about half way (1 cm) but not crumbling away, the web and bottom flange are ok.
I was going to add wood to the webbing to support a sunken floor for a curb less shower like the image. Would that be enough extra support or is there anything else I can do to support the damaged I-joist?

Its a wooden i beam not a steel, I would be cautious about treating the bottom flange as sufficiently load bearing for a shower tray.

 

[adam992]

I can't find much info on how to sister an I-Joist. Would it be nailed through the web only? Does the sister I-joist need to run. The full length or just cover the rotten section?

Thanks for the input so far.