Can I use joist hangers?

[Robster_1981]

I've had my floor boards up and noticed that the ends of 2 of the joists have started to rot and sag. There is a horizontal joist about 750mm from the wall that is currently supporting the lateral joists (if that makes sense?) so my question is, can I span this short gap with new joist and hang from the wall with joist hangers?

http://www.screwfix.com/prods/73487/Building/Builders-Metalwork/Joist-Hanger-50mm-x-175mm

Edit: it's an external cavity wall that i'll be fixing to

 

[noseall]

The joist hanger in the image is a build-in type.

Jiffy or speedy hangers are similar but made from thinner steel and are designed for fixing to a timber plate.

Either are acceptable in most domestic joist hanging scenarios.

Trimming joists is another matter and may require additional timber.

But, all connections can be dealt with using hangers.

This post may need a piccie.