I am trying to understand how this is done as the profile is normally screwed into the plasterboard and presumably then into a background joist but this isnt possible when using res bars so how do you keep the profile in place? I am assuming just screwing into the plasterboard wont be enough? 

 

Would it be better gluing with something like CT1? Thanks

We glued with pink grip

Don't all plaster-in lights like downlights just get screwed into the plasterboard and then the skim coat also helps to hold them in place. By definition you can't put a downlight underneath a joist.

 

Don't you just need to use a plaster-in LED profile, screw it to the plasterboard and then plaster it in with the skim coat ?

looking at the photo looks like I used some plasterboard screw as well. Can’t remember if they were in to the res bars or not though. Sorry. 
 

i’m sure pink grip would be strong enough though. Our plasterers used it for all the edge beadings. 
 

@nod will be able to give you a definitive answer though. 

Didn't know you could get crazy bendy profile like this one...

 

https://reeltechdirect.com/products/flexible-plaster-in-led-profile

 

Admittedly a lot of these profiles are as deep as the plasterboard. I guess maybe double boarding the ceiling is the answer or you will end up cutting right through the board ?

I am putting some in rooflight upstands, but here the plasterboard attaches directly to the continuous insulated plywood upstand.

The easiest way is to mark you lights on the floor and run a length of top hat either side Then add a 100 mil pattress in between the two top hats Board your ceiling Then transfer the lines from the floor and cut out 

 

If you must use res bar You can fix pattress in between but on to the joists 

If you don’t put timber in They will crack 

@nod thanks - having a bit of an issue visualising this mainly because I am unsure what "top hat" is? You dont have any sort of picture of what you mean do you?

27 minutes ago, markharro said:

@nod thanks - having a bit of an issue visualising this mainly because I am unsure what "top hat" is? You dont have any sort of picture of what you mean do you?

https://www.ceilingtilesuk.co.uk/product/mf5-furring-channel-top-hat-3600mm-mf-ceilings/?1&ft=true&utm_campaign=PMAXW-Shopping&gad_source=1&gad_campaignid=21670932886&gbraid=0AAAAADxRNNWI9JmkQ-Qpl9DkshjATYJ-U&gclid=CjwKCAjwl_XBBhAUEiwAWK2hzqSPXOY1GzYYPCyOeSp9yPUlQdr59EVk7yMhPyOjZN4A5M94PsGpzBoCq78QAvD_BwE

@markharro did you sort this? I'm at this exact conundrum myself..

Yes I did. I used this stuff https://soundstop.co.uk/products/genieclip-furring-strip?variant=43491336880351 and these clips https://soundstop.co.uk/products/genieclip-rst-soundproof-system?variant=43491336782047 I found this company really good to deal with and very helpful over the phone. Fixing the bars was pretty easy - shimming the joists took the most time.

 

I bought 2 different types of LED profile - one like in @Thorfun photo above (yet to fit this) and another being this one - https://www.ultraleds.co.uk/plaster-in-wall-washer-led-aluminium-profile-85-5mm-x-56-8mm which butts up against the wall. I have fitted the latter only and what I did was to measure the gap for it very carefully and then fit the first metal bar so that the screws through the profile would go into the metal channel. As ever the time was in the working it out and measurement. Once I had got my head around how to do it things went very smoothly. Here is a photo of the ceiling now painted.

 

I won't be fitting the others for a while. Haven't really thought about how to do these. One way I guess is to fit 2 parallel resilient bars with a gap just wide enough for the profile?

On 02/06/2025 at 19:31, nod said:

 

If you must use res bar You can fix pattress in between but on to the joists 

Won't that, in part, negate what the resilience bars do?

12 minutes ago, SteamyTea said:

Won't that, in part, negate what the resilience bars do?

It would I wouldn’t do the two together 

 

@SteamyTea and @nod you are both right I think but in this shower room the bars were used mainly to get the ceiling height level with the tiles and any acoustic benefits will be a bonus

1 minute ago, markharro said:

in this shower room the bars were used mainly to get the ceiling height level with the tiles and any acoustic benefits will be a bonus

When I shared a student flat in the 1980's, had a flat mate that played his clarinet in the bathroom.  Anything that drowns out the sound of Baker Street is more than a bonus.