soon i will be starting my loft conversion but i have a question for an alternative for the traditional 9x2 floor joist. The span of the new floor steel to steel will be six metres, my architect has suggested using 9x2 at 400c/c and lapping them over the central supporting wall thus making each joist either 3.3 or 3.6 "can't remember" now i have done a few loft conversions and know from experience when using joist in this manner that inveriably you end up with a floor that isn't strictly level. Now to avoid this i would like to use TJI joist because i know you can then span the entire six metres without having to cut them in half, however, as always cost is an issue therefore do you feel that the amount of time i would save by using TJI joists as appose to messing around with 9x2 would be beneficial from a financial and time perspective?