Lower the ceiling in the whole apartment - indecision

[blizzard]

Hello,

I have now read a whole lot of posts but I'm not getting any wiser and I'm strongly starting to believe that I have some kind of attention disorder.
I want to lower the ceiling in the entire apartment except for the bathroom and at the same time, I want to hide the ventilation under the ceiling which currently consists of exposed spiral ducts. LED spotlights will be installed, and the electrical wires and cables will also go up into the ceiling.

The spiral ducts will be replaced by square PVC ducts and they will be 50mm high.

Now to the anxiety...

I know that one can use regular wood studs, but 45mm isn't enough to cover the ventilation, so in that case, I have to add on with a 22X45 batten on the wood stud to get an OK height.
How do I best and most securely attach the 45X45 stud to the concrete ceiling?
Expander nails?
Is 45x45 enough, or do I need a thicker one? Cables will either be drawn through drilling in the stud or by creating "gaps" in the battens...

However, there will be a lot of drilling into the ceiling to attach, so I started considering metal studs.

But I want to lower as little as possible and some walls are gypsum which leads to the possibility of needing a "hanging" ceiling. But these ceilings have a maximum span width if I understand correctly? Do you calculate the span width for the primary or secondary?

The primary needs to be attached with a strap or band that is fastened to the ceiling and then bent 90 degrees and attached to the primary. How do I attach this strap/band to the ceiling?
Do I need a gap down to the primary, or can I push the primary all the way up against the ceiling and then secure it with 2 screws through the band? This to minimize total height.
Feels like the primary will bend, but maybe that’s why you have "tracks" around the walls also for stability? But is it okay to run these tracks around the walls even where I have gypsum?

There is quite a bit of weight to be held up and if my calculations are correct, the weight is well over 600 kg.

Since I have limited ceiling height, I wonder if masonite/hardboard can be used instead of gypsum and maybe reinforced with painting canvas?

Grateful if some kind soul can guide me so that the anxiety disappears (whiskey doesn't help) =)

 

[Demmpa]

I want to lower the ceiling in the entire apartment except for the bathroom, and at the same time, I want to conceal the ventilation under the ceiling, which currently consists of exposed spiral ducts. LED spotlights should go up, and electrical wiring and cables should also be placed in the ceiling.

The spiral ducts will be replaced with square PVC ones and will be 50mm high.

Where are the spiral ducts?
What do the spiral ducts connect from?

If the spiral ducts are from the kitchen fan/hood/extractor over the stove, then it's the extraction duct, which must consist of spiral ducts. If the extraction duct is shared with multiple condo units, the entire length must be fire-insulated to at least EI15.

Edit: read this thread
http://www.byggahus.se/forum/showthread.php?t=236109

 

[Larsa]

Use steel studs instead. You can use 70mm instead of 22+45. Hanging the studs from the ceiling is not an issue in terms of load-bearing. Use nail anchors or anchors and screws.

 

[slacker]

Use metal studs instead. You can use 70mm instead of 22+45. Hanging the studs in the ceiling is no issue regarding load-bearing. Use nail plugs or plugs and screws.

Agree with Larsa on this...

However, I think that nail plugs and metal studs are a bad combo - It's doable, but it's easy for the plug to go through the stud. So I've used nail expanders a few times with good results.

 

[blizzard]

Where are the spiral pipes?
From what do the spiral pipes go?

In the kitchen, I have a vent in the wall with exhaust air. However, the spiral pipe is for the other rooms in the apartment and it's intake air in these, and the pipes go through the wall in the closet and out into the apartment.
I think it should be fine to use regular PVC out into the apartment with intake air?

 

[blizzard]

Use steel studs instead. You can use 70mm instead of 22+45. Hanging the studs from the ceiling is not a problem regarding load-bearing. Use nail plugs or plug and screw.

Hey Larsa,

But if I use a 70mm primary steel stud, then I need to use a secondary at least 25 mm, and then we're up to 95 mm + 13 mm gypsum = 108 mm.

Maybe I can use only primary studs and skip the secondary? As mentioned, I want to lower as little as possible.
And is it OK if I use a perforated band and push the primary tightly against the ceiling and then attach the band to the primary? I don't want a "pendulum" down to the primary...
See the attached image to see what I mean =)

 

[blizzard]

I agree with Larsa on this...

However, I think a nail plug and sheet metal stud is a bad combo - It works, but it's easy for the plug to go through the stud. So I've used nail expanders a couple of times with good results.

[image]

Hey Slacker,

Thanks for the info. I'll probably go with a nail expander and entirely in metal. BUT sometimes expanders are sold without a nail
Is it meant that you should also drive in a nail?

 

[slacker]

Hey Slacker,

Thanks for the info. I will probably go with a nail anchor, entirely in metal. BUT sometimes expanders are sold without nails [image]
Is it intended that you also insert a nail?

It’s true that this variant exists as well - I go with the "complete" one I showed a picture of, as it has a larger head with a flat collar and is less likely to tear the sheet metal.

You can skip the primary entirely if you instead choose to put bands on all the secondaries - This involves a bit more work to set it all up, but it definitely saves ceiling height.
Then, I would probably put L-Profiles around the room and then secondaries in these to install patent bands in all secondaries and then to the ceiling.

Are you following me =)

 

[blizzard]

Keeping up with me? =)

Hello again,

I have just gotten it in black and white that I'm slow =) I get what you wrote about L-profiles around, but I have a drywall that might not be the most stable and solid. Therefore, I'll try to attach the "frame" to the ceiling on the side where the drywall runs.
It must be possible to use angle brackets for this?
Instead of an L-Profile, maybe one can use a regular track (for floors and ceilings when making interior walls?)

In my opinion, secondaries are a hat profile or a regular steel stud used for walls? but how the heck to attach with metal bands if using a hat profile? Maybe skip the hat profile entirely and only use regular metal studs?

Thank you for taking the time to reply =)

 

[slacker]

When it comes to the drywall, there are studs in it too - If you hit one of them, it should be fine, unless there's already OSB in the wall? Attaching to the ceiling is also possible, and using angle brackets is not entirely wrong. A regular track and an L profile are essentially the same - I usually go for the L profile because it's simply cheaper. The setups, as I call them, cost a bit more.

Secondaries are the hat profile, completely correct - Studs intended for the wall I would call sheet metal or steel stud and nothing else. You fasten the metal strips to the ceiling with some form of plug/screw, and you can then attach the strip with "blueberries" (Self-drilling machine screws) also called "knort" (!?) I've heard, in the metal stud, you can easily bend the strip around the secondary.

The only downside I can see with using regular metal studs for the ceiling is that there's no rigidity on the lip of the stud, i.e., when the panels meet on a stud and are fastened, there can be a misalignment since the lip you're screwing into is only supported on one side. But it should work - I haven't tried it myself...