We have demolished an inner wall, and to conceal the "joint" in the concrete ceiling and to encase the electricity that was previously routed in the wall, we will build a box/duct in the ceiling. At the same time, we intend to install spotlights in this box, and for a short stretch, it will also house a ventilation pipe (the spots and ventilation pipe do not need to be in the same place).
A similar duct already exists in the ceiling to hide the ventilation pipe, built from four wooden battens, about 50x23 mm in profile and 13 mm thick gypsum, mounted to the ceiling with nylon plugs and approximately 9 cm long screws. The duct is 23.5 cm wide and 19 cm from top to bottom.
The idea for the dimensions of the new duct is 32 cm in width and 19 cm in height from top to bottom, so it will hide all the damage in the ceiling and then meet the previous duct at the same height.
What should we use for battens in this construction? I guess it’s a balance between being strong enough while not being too heavy? (50x23 mm used in the existing duct seems not to be available at the nearest hardware store). Is gypsum the best material to cover with, or are there better alternatives? Are nylon plugs and screws sufficient to hold up the construction, and how long do the screws actually need to be (concrete ceiling, built in 1935)?
Very grateful for your help.
/Karin
A similar duct already exists in the ceiling to hide the ventilation pipe, built from four wooden battens, about 50x23 mm in profile and 13 mm thick gypsum, mounted to the ceiling with nylon plugs and approximately 9 cm long screws. The duct is 23.5 cm wide and 19 cm from top to bottom.
The idea for the dimensions of the new duct is 32 cm in width and 19 cm in height from top to bottom, so it will hide all the damage in the ceiling and then meet the previous duct at the same height.
What should we use for battens in this construction? I guess it’s a balance between being strong enough while not being too heavy? (50x23 mm used in the existing duct seems not to be available at the nearest hardware store). Is gypsum the best material to cover with, or are there better alternatives? Are nylon plugs and screws sufficient to hold up the construction, and how long do the screws actually need to be (concrete ceiling, built in 1935)?
Very grateful for your help.
/Karin
Some spotlights require a minimum distance to combustible materials, and in that case, it might make sense to use metal studs + 13 mm gypsum, to avoid installing metal boxes above the gypsum that shield the spotlights. If you're going to use spotlights that don't require this distance, like Vinga Vision, you can use 45 x 45 mm wooden studs. If you want to build tightly around ventilation pipes or similar, sometimes it can be helpful to use a metal angle H50/50 instead of studs.
If you have a proper concrete ceiling, you can attach the wooden stud to the ceiling using nail plugs, such as 8x100 mm. Just drill through the stud and up into the ceiling and then hammer in the nail plug. If you're using a metal stud, choose a shorter nail plug, such as 5 x 40-50 mm.
If you have a proper concrete ceiling, you can attach the wooden stud to the ceiling using nail plugs, such as 8x100 mm. Just drill through the stud and up into the ceiling and then hammer in the nail plug. If you're using a metal stud, choose a shorter nail plug, such as 5 x 40-50 mm.
Thank you ACME for quick and good tips!
Lack of knowledge and experience makes me have no idea what constitutes a "proper" concrete roof and what does not. If it turns out that our roof is not proper, what would be good to use to ensure the construction remains intact?
Regarding the choice of studs, I interpret it as that wooden studs are best except when there are special reasons to use metal? This may be an overly general question, but right now I can't really see any advantage of wood over metal studs for our small build.
/Karin
Lack of knowledge and experience makes me have no idea what constitutes a "proper" concrete roof and what does not. If it turns out that our roof is not proper, what would be good to use to ensure the construction remains intact?
Regarding the choice of studs, I interpret it as that wooden studs are best except when there are special reasons to use metal? This may be an overly general question, but right now I can't really see any advantage of wood over metal studs for our small build.
/Karin
It will probably be fine to use nail plugs for the ceiling, or alternatively longer coarse thread wood screws with nylon plugs (not yellow/red/brown/blue plastic plugs).
Wooden studs are nicer to screw into, provide a slightly more stable construction when using thin dimensions, and are cheaper than metal.
Metal studs are lighter, always straight, and there is a whole range of different profiles that facilitate different types of assembly.
For your construction, it doesn't really matter which option you use, but if you are inexperienced, it may be nice to avoid wrestling with crooked timber.
I would suggest you purchase;
Metal tracks SK45 (for the layout, not the studs) to attach on each side of the ceiling.
Corner profiles H50/50 to place on the inside of the "outer corners" of the drum.
13 mm drywall.
Drywall screws for metal studs.
5 x 50 mm nail plugs or nylon plugs and 50 mm wood screws with a rounded head (not countersunk).
If the drum will change dimensions anywhere, or if you need to splice the studs, you can easily screw them together with 13 mm assembly screws with a drill point.
Cut the studs with tin snips or use a jigsaw with a metal blade. A hacksaw probably works fine too when it's not a large quantity.
Wooden studs are nicer to screw into, provide a slightly more stable construction when using thin dimensions, and are cheaper than metal.
Metal studs are lighter, always straight, and there is a whole range of different profiles that facilitate different types of assembly.
For your construction, it doesn't really matter which option you use, but if you are inexperienced, it may be nice to avoid wrestling with crooked timber.
I would suggest you purchase;
Metal tracks SK45 (for the layout, not the studs) to attach on each side of the ceiling.
Corner profiles H50/50 to place on the inside of the "outer corners" of the drum.
13 mm drywall.
Drywall screws for metal studs.
5 x 50 mm nail plugs or nylon plugs and 50 mm wood screws with a rounded head (not countersunk).
If the drum will change dimensions anywhere, or if you need to splice the studs, you can easily screw them together with 13 mm assembly screws with a drill point.
Cut the studs with tin snips or use a jigsaw with a metal blade. A hacksaw probably works fine too when it's not a large quantity.
Thanks again ACME for the great information!
Upon closer inspection of previous constructions hanging from the ceiling, it actually looks like they are mounted with nail plugs, so we'll probably go with that again. Whether it will be wood or metal, we'll have to think a bit more about.
/Karin
Upon closer inspection of previous constructions hanging from the ceiling, it actually looks like they are mounted with nail plugs, so we'll probably go with that again. Whether it will be wood or metal, we'll have to think a bit more about.
/Karin
Everything for a Happyit! 
/Acme aka Buddha
/Acme aka Buddha
Well, that was typical, happy can surely provide an answer to everything!