Hello
I am expanding the house with a few new rooms. Between these rooms (bedrooms), there is a 70mm wall with OSB + plasterboard on both sides. The walls are filled with 70mm mineral wool from top to bottom.
Thus: The walls will probably be quite adequate. However, the walls are erected against the lath ceiling, and in some cases, it's completely open between these rooms along the laths. So, if I stand on a ladder and look at the ceiling along the laths, I can see from one room to the other.
How do you make this part right? Even when I plaster the ceilings on both sides of the rooms, the sound will likely have a very easy path to travel up into the ceiling, between the laths, and down into the other room. Between some rooms, the laths run in the other direction, and then it's tighter, in a way. There might be other problems in those cases.
Should I press mineral wool between the laths, similar to caulking around a door? Or perhaps take it a step further by pressing in insulation as a strip insulation the 20 cm closest to the wall in both rooms? What do people normally do?
Thanks for the tips!
I am expanding the house with a few new rooms. Between these rooms (bedrooms), there is a 70mm wall with OSB + plasterboard on both sides. The walls are filled with 70mm mineral wool from top to bottom.
Thus: The walls will probably be quite adequate. However, the walls are erected against the lath ceiling, and in some cases, it's completely open between these rooms along the laths. So, if I stand on a ladder and look at the ceiling along the laths, I can see from one room to the other.
How do you make this part right? Even when I plaster the ceilings on both sides of the rooms, the sound will likely have a very easy path to travel up into the ceiling, between the laths, and down into the other room. Between some rooms, the laths run in the other direction, and then it's tighter, in a way. There might be other problems in those cases.
Should I press mineral wool between the laths, similar to caulking around a door? Or perhaps take it a step further by pressing in insulation as a strip insulation the 20 cm closest to the wall in both rooms? What do people normally do?
Thanks for the tips!
Tool enthusiast
· Stockholm
· 1 399 posts
You need to plaster the ceiling so it fits tightly against the walls and forms a shell.
Thank you, but do you mean that it's enough to match the level of the wall?
It feels like the ceiling is a highway for sound in comparison. The wall has four sheets plus insulation. The ceiling has, as I see it, two sheets and nothing else that the sound needs to pass through (up from one room's ceiling plasterboard and down into the other). But maybe I'm thinking wrong.
It feels like the ceiling is a highway for sound in comparison. The wall has four sheets plus insulation. The ceiling has, as I see it, two sheets and nothing else that the sound needs to pass through (up from one room's ceiling plasterboard and down into the other). But maybe I'm thinking wrong.
Tool enthusiast
· Stockholm
· 1 399 posts
If you slice the ceilings in both rooms equally as the partition, the sound has the same barrier to get through (wall/ceiling). You don't actually need to have quite as much mass in the ceiling vs the wall due to greater distance/gap, etc.
Thank you for that.
If you think of the wall looking like this from one side to the other:
plasterboard - OSB - 70mm insulation - OSB - plasterboard
The ceiling, on the other hand, is plasterboard against battens. Therefore, my plan is not to board the ceiling the same way since it lacks OSB. There is also no insulation between the rooms above the wall (between the battens).
So what do I do to ensure the plasterboard ceiling soundproofs well enough? I can make sure the plasterboard is sealed tightly. I can seal the joints between the wall and the ceiling. But I’d gladly go a bit further. Not so far as to have double layers of boards on the ceiling unless some pretty strong arguments for it come up. I'd rather add a bit of insulation, provided we believe the solution is good.
If you think of the wall looking like this from one side to the other:
plasterboard - OSB - 70mm insulation - OSB - plasterboard
The ceiling, on the other hand, is plasterboard against battens. Therefore, my plan is not to board the ceiling the same way since it lacks OSB. There is also no insulation between the rooms above the wall (between the battens).
So what do I do to ensure the plasterboard ceiling soundproofs well enough? I can make sure the plasterboard is sealed tightly. I can seal the joints between the wall and the ceiling. But I’d gladly go a bit further. Not so far as to have double layers of boards on the ceiling unless some pretty strong arguments for it come up. I'd rather add a bit of insulation, provided we believe the solution is good.
Tool enthusiast
· Stockholm
· 1 399 posts
Are the ceilings already plastered? You should have insulation in the joists above the frame. It should not be packed, and you don't need to completely fill the spaces in height.
The ceilings are not plastered yet, right now the battens are exposed and that's why I'm wondering if I should insulate between them (and possibly other measures) before plastering.
Above the battens, there is a vapor barrier and a lot of insulation, but as I see it, it's at the level of the battens where the problem is, meaning that between the battens I can see from one room to the other.
Above the battens, there is a vapor barrier and a lot of insulation, but as I see it, it's at the level of the battens where the problem is, meaning that between the battens I can see from one room to the other.