loft joists and spine wall solution

[elliottoliver]

hi after reading so much on this site wich has been very helpfull i just have one small query we are fitting 8x2 joists in the existing loft from wall plate to spine wall and the same the other side and bolting them together in the middle and to the raffters at either end the loft is 5mx7m my problem comes over our existing landing as the spine wall does not continue all the way across the 5m length we were going to bolt 3 joists together either side of this and gap (aprox 2m) and joist hanger a doubled joist central to the two then joist hanger single joist back out to the wall plate to compensate for no spine wall.
my problem is as i am running the new joists 18mm above ceiling height and i would have to cut a central section of the old joists out to accomadate my new doubled joist as they run in opposite directions but then these joists would be free and not supporting the ceiling below which is not good does anybody have a solution for me please were not fully converting yet as no cash but aquired our new joits and have no were to store them so must be fitted

 

[PaulJR]

hang the ceiling joists from your new joists.

use a couple of the 8"x2" laid over the triples and temporarily hang the ceiling off these until you have your trimmer in place then either fix the ceiling joist to the trimmer or to your new joists.

The reason you leave a gap between joist and ceiling is so that the new joist don't pop the boards off them when they deflect under load and the ceiling doesn't. If you fix these short spans together you are very unlikely to have any problems.

 

[elliottoliver]

thanks i didnt know wether the new floor had to be totaly independant of the old one thanks i can now begin