Flat roof Joists too short (Ed.)

[heatingdilemma]

We have a flat roof on our ground floor which acts as a large bay area to our living and kitchen area. It's approximately 5 meters by 2.5 meters.
We have an issue in that the builder (who has since done a runner but that's another story) mis measured our steel and had to fit new steels after the original joists had been bolted to the steel work. He did this, it turns out, by cutting the joists off the steel and only reattaching 2 of the joists. We now need to get all the joists attached to the steel but they're slightly short.
We are wondering if there is someway to extend the joists, so some sort of bracket maybe and then put a new bit of joist on which we could then attach to the steel. All ideas welcome.

 

[freddiemercurystwin]

You can sister the joists but photos always help ....

 

[^woody^]

Splice and glue and screw plywood gussets ether side of each joist.

If it's only a short distance, fix timber to the side of the beam to close the gap.