Improving weak ceiling grid for plasterboard

[mrdman]

I'm in the process of fixing up the ceiling in the garage and am planning on doing it in two phases.  First getting some XPS up there to hold up the existing rockwool as it's beginning to fall down.  No idea why the past owners thought that would be a good ceiling tile at 1.2m x 1.2m !

Then I'm planning on plasterboarding it.  However, looking at how the structure has been fixed, I don't think it's strong enough for plasterboard.  Firstly, it's just nailed into the block wall.  

Secondly, they are tied to the roof purlins with metal twine which is 1.6mm diameter.

I was going to leave those two issues until I get to the plasterboarding, but it'd be much easier to sort it out now while I'm doing the XPS with easy access.

So my questions are:
1.  Am I right in assuming nailing to the wall isn't good enough.  I should screw into the wall at 600mm spacing?  How would you go about it?  Are there special screws made for this purpose? Or do I drill through the metal with a HSS bit until just through, then switch to a masonry bit to finish? Then push a rawl plug through and fix the screw? I guess I'd need a roundhead and a washer as the hole would be oversized in order to fit the rawl plug through?

2.  Am I right in assuming that 1.6mm twine isn't strong enough for plasterboard?  How would I go about getting a stronger fixing there?  Most of the clips I've seen are specific to their system.  So maybe it's a case of simply a thicker rod that I can bend over the purlin and through the existing hole?  What diameter would you recommend?

Any help greatly appreciated!

[nod]

The pictures show a suspended grid ceiling 

You can’t fix plasterboard to this It will collapse 

[mrdman]

21 minutes ago, nod said:

The pictures show a suspended grid ceiling 

You can’t fix plasterboard to this It will collapse 

Ah ok.  What makes it unsuitable for plasterboard in comparison to the suspended ceilings such as MF ceilings for example?  Anything I can improve?
 

[Declan52]

Plasterboard needs something substantial to attach to so it can hold its weight plus keep its shape so it stays flat. The suspended ceiling you have is for very light weight ceiling tiles. The metal and wire used is suitable for the ceiling tiles but will just bend and collapse if you attach plasterboard to it.

[mrdman]

9 minutes ago, Declan52 said:

Plasterboard needs something substantial to attach to so it can hold its weight plus keep its shape so it stays flat. The suspended ceiling you have is for very light weight ceiling tiles. The metal and wire used is suitable for the ceiling tiles but will just bend and collapse if you attach plasterboard to it.

The problem is I can't find any 1.2m x 1.2m ceiling tiles so these XPS boards (1.2m x 0.6m) are sort of a stop gap before something better.
 

What would you do if you were me?  
Put a new grid underneath the existing one that's made for plasterboard?  
Or buy some steel profiles to make the grid into 0.6m x 1.2m to support the XPS better and leave it as is?  Is that a fire hazard?

[nod]

Just now, mrdman said:

The problem is I can't find any 1.2m x 1.2m ceiling tiles so these XPS boards (1.2m x 0.6m) are sort of a stop gap before something better.
 

What would you do if you were me?  
Put a new grid underneath the existing one that's made for plasterboard?  
Or buy some steel profiles to make the grid into 0.6m x 1.2m to support the XPS better and leave it as is?  Is that a fire hazard?

You can use 600 x 600 Simply jus add a bar for them to sit on The holes are already in the existing Just click the new bar in 

They are about a £1 each 

[mrdman]

17 minutes ago, nod said:

You can use 600 x 600 Simply jus add a bar for them to sit on The holes are already in the existing Just click the new bar in 

They are about a £1 each 

I've seen those click systems on other ceiling grids, but this one seems to be different.  It's not fixed anywhere and no holes or clips or anything.  Very strange.  I've taken some more pictures to show it all better.  

Have you seen anything like this system before?  Really appreciate the advice.
 

[nod]

Yes I use them all the time Mainly on offices and shops 

While yours is quite dated It still looks ok 

If you decide to replace the tiles with 600 x 600 You can now get tiny clips that will stop the tiles lifting 

While the ceiling is not load bearing you could run 25 mil insulation on the top before you re tile 

 

[mrdman]

Ah ok, that sounds positive.  Glad to hear from someone who's come across these before.  I would like to fit some sort of tile there yes, as the exposed XPS I believe is a fire hazard (?), and it doesn't look great anyway.  So if I can turn it into a 600 x 600 grid, that would make my life much easier as I can then get a selection of tiles that'll drop in.

Would you be able to point me in the direction of the clips you're talking about?
Or even to something that could work as the bar.  I've not been able to find anything similar to what's there already.  (Apart from welding together two angle irons which I want to avoid!)

[TonyT]

https://www.uksuspendedceilings.co.uk/product/xt24-suspended-ceiling-perimeter-angle-wall-trim/

 

have a look at this website or Armstrong 

[mrdman]

6 minutes ago, TonyT said:

https://www.uksuspendedceilings.co.uk/product/xt24-suspended-ceiling-perimeter-angle-wall-trim/

 

have a look at this website or Armstrong 

You mean you'd recommend just buy 2 standard perimeters and use them back to back rather than look for a plain T similar to what there is already?  Yes, that's probably the easiest.

Thinking about it now actually.  Maybe I should forget about having 0.6m x 0.6m grids anyway because that would mean running another full length channel.  Maybe I should try for a 1.2m x 0.6m grid, in which case I'd only need some of those 0.6m Ts.  And I can get hold of 1.2m x 0.6m tiles.

[TonyT]

No I was linking to a website for you to find out what you are looking for