Hello!
I am planning to build a dormer for my 1 1/2-story house and am considering soundproofing the existing wall (long side) between two bedrooms on the upper floor in connection with this. It's noisy between the rooms, but I can't determine what goes through the wall and what is flank transmission.
The wall is about 100 mm. Let's assume a 70 mm rule with cc 600 mm and single drywall.
The short side of the bedrooms faces the house gable and each has a window close to the partition wall. That is, the gap between the gable windows is the wall thickness. I want to avoid increasing the gap between the gable windows as much as possible.
I've considered the following solutions:
a) Double drywall + insulation => adds 25 mm in width
b) Double drywall + insulation + staggered wooden stud => adds 50 mm
c) Double drywall + insulation + staggered wooden stud on steel sill => adds 50 mm
d) Double drywall + insulation + staggered steel stud => adds 50 mm
I have a crazy idea as a variant of option b to tear down from one side, split the sill and wall plate by 25 mm (i.e., reduce to 45 mm) and add a 45 mm rule next to it. Double sills have a thickness of 115 mm (45 mm sill+ 10-25 mm gap 45 mm sill = 115 mm). Double drywall on this gives 150 - 165 mm, i.e., adds 55 - 70 mm.
The short gap (< 25 mm) requires cutting the corners of the stud ends to avoid a sound bridge; alternatively, you use a 45*45 rule.
Has anyone tried this concept? In other solutions, I've only seen sills of 2*70 mm, which gives a sill width of at least about 150 mm and wall thicknesses over 200 mm.
I hope you understand my description; the idea is to remove the sound bridge that the sill and wall plate would otherwise create.
Other tips are very welcome!
Best regards, Perhof
