Levelling a ceiling prior to boarding

[crispy_wafer]

I'm seeking a bit of advice on how best to level a ceiling in preparation for boarding.

 

The bit of ceiling is in our dormer, I've attached an old picture from last year showing the offending items.  When measured from the laser, they are either about 3mm/7mm/12mm higher than the lowest timber cross (whasitcalled!)

 

The area in the picture has all been insulated under, divided and stud walls added since that photo, so the main room in that area has 7 bits in total. 5 to deal with as 2 are level at the lowest point!

Floor to timber is around 2330 - ish

 

Not knowing how to deal with this properly/professionally, I started a thinking (dangerous), then consulted the google (probably even more dangerous).

 

1) use 3mm hardboard in multiple layers along the timbers to make up the depth and that'll do!

2) I have a load of res bar, that I could fix perpendicular, and pack out where i need to make level.

3) I have some c channel left, so lower the ceiling slightly by fixing c channel like the pic below

 

4) what would a pro do?

 

[Russell griffiths]

Resilient bars and get the little metal hangers so you pull them up or down as needed. 

[Radian]

9 minutes ago, crispy_wafer said:

(whasitcalled!)

Collar tie.

C channel or anything mounted parallel to the ties is going to work. Our attic trusses were all over the place and got sorted by screwing a whole bunch of 2x4 like in your illustration.