Attaching "packing" timber onto existing RSJ through ceiling board

[Bokvis]

Hi, appreciate advice/ comments on how best to approach this please

We have an internal support wall with an steel RSJ already in situ and plastered boarded over. We are looking to install a set of internal French doors + frame which will require packing out with a 72mm thick timber (reflected in yellow below) before we can install the timber frame + doors

Problem we are facing, is that there is a 30mm gap between the plasterboard and the steel RSJ. I intend to secure the new timber frame into the 72mm timber in yellow. So it is the timber 72mm through existing 12mm (not 18mm) plasterboard + 30mm gap in between to RSJ that requires fixing totalling 103mm without RSJ allowance

How best to approach this please - pilot hole using what type of drill bit and do i used a TEK screw - if so what size and type please ?

Thank you for your help

 

[lostinthelight]

Could you not cut hole out of the plasterboard with enough clearance to push the new wood up through and against the Rsj...not sure if there any fire regs that prevent having flammable material in contact with the steel mind

 

[foxhole]

Foam fix the timber, plenty of support from frame as the doors hang on the side timber very little is hanging on the top of frame.
(You could countersink a couple of holes in upper timber to allow a 100mm tek tight screw to reach steel .)

 

[foxhole]

Foam fix the timber, plenty of support from frame as the doors hang on the side timber very little is hanging on the top of frame.
You can countersink a couple of holes in upper timber to allow a 100mm tek tight screw to reach steel .)

 

[robinbanks]

Agree with foxhole; doesn't appear to be any need to disturb the ceiling or fix anything to the RSJ, just install the door frame and a 72mm filler, which will help the top of the frame avoid sagging, but fixing the top of the frame isn't necessary to retain the doors; they get their support from the side walls

 

[Bokvis]

Thank you all for the responses. Makes sense. I think I will use a few 100mm counter sunk Tek screws into the RSJ as concerned about any sideways force on the door I.e slamming …maybe a bit overkill

Would I need to try and drill a pilot hole and if so, is there a specific metal drill bit required or would a standard type suffice?

Many thanks - really appreciate the advise

 

[foxhole]

Tek screws are self drilling.