Joist do not go through wall (how to acro)

[stash2014]

Hi all,

I am knocking 2 upstairs bedrooms together (with building permission) a double door with pocket doors, sb100 lintel. One of the rooms previously had a chimney in it so all the joists in both rooms don’t run through the internal wall. They do at each end of the room but there is probably a 2m run where they are attached to a timber parallel to the wall, my plan is to use triple boards to acro this spanning way past the 2m. I have 3 acros and stongboys & the doorway I am making is probably about 1.5m. Just wondered if this is correct, I have contacted my structural engineer but just trying to plan ahead of things, thanks for the help (crude drawing attached)

 

[^woody^]

You will need more props. 2, maybe 3 more

I don't understand the tripple board thing.

You need timber on the floor as well as the ceiling to spread the load

 

[stash2014]

I was going to triple board the floor because the only joists that go through the wall are at the ends of the room

 

[^woody^]

A 4x2 will do, and props at about 1m spacing