Brick Inner Leaf. Advantages and Disadvantages?

[DanDan]

Sorry to cause confusion. In order to enhance the LF absorption, and if building codes allow, I was suggesting using the minimum number of studs. I believe metal studs are also inherently more flexible. I suggest installing a layer of neoprene or other springy material under the floor plate and above the ceiling one. Again codes permitting, I would glue the neoprene to the stud and floor rather than using screws or bolts.

[Skai_Penalva]

Hello DanDan,

Thank you for clearing that up! I went over your response with the structural engineer. He is concerned about the construction of the wall layers. He says any kind of geosynthetic material is accessible here. Not so sure about sheet lead or vynil. What other materials would be efficient for the wall layers?

[Paulus87]

Hello DanDan,

Thank you for clearing that up! I went over your response with the structural engineer. He is concerned about the construction of the wall layers. He says any kind of geosynthetic material is accessible here. Not so sure about sheet lead or vynil. What other materials would be efficient for the wall layers?

Did anyone mention sheet lead or vinyl? I don't remember reading about that in your thread.

So, is there any reason you can't use good old drywall, plywood, OSB for your wall layers?

Paul

[Skai_Penalva]

What I am describing is simply stud walls with layers of drywall, and perhaps some bitumen deadsheets between the drywall panels.

I may have gotten confused with this comment. Is this not what you meant? I mentioned the vynil or leadsheets since that is what seems to be used and recommended in many other posts here.

[Skai_Penalva]

So, is there any reason you can't use good old drywall, plywood, OSB for your wall layers?

Paul

Oh, I can definitely use drywall, plywood or OSB for my wall layers. Are you suggesting I use all 3, or just either of these?

[Paulus87]

So, is there any reason you can't use good old drywall, plywood, OSB for your wall layers?

Paul

Oh, I can definitely use drywall, plywood or OSB for my wall layers. Are you suggesting I use all 3, or just either of these?

I like to use 5/8" OSB3 as the first layer as it adds a structural strength to everything, making your framing so much stronger. Then just use the cheapest material with the most surface density. Usually this is 5/8" drywall. 2 - 3 layers is usually enough, especially if using over the OSB.

Attach all the boards in the same orientation, but offset the seams so that every seam is covered by the next layer of mass. Before attaching each layer, seal all the seams with a non hardening caulk. Stagger the joins at the corners and the wall/ceiling junction, and leave a tiny little gap if you can at each junction into which you can push in backer rod before caulking over to seal it all air tight.

There is very little benefit in using different thicknesses of drywall or different materials in the walls since once they are all nailed together they essentially act as one mass layer.

Paul

[DanDan]

Many people do recommend Mass Loaded Vinyl for enhanced sound blocking when there is no depth available. There are those that promote hanging dead sheets, and MLV fronts on membrane bass traps. Here in Ireland it is a no brainer, those materials and other esoteric such as Green Glue cost a small fortune here, if you could even get them.

Many designers and builders restrict themselves to using readily available often cheap materials. That was even part of the BBC ethos.
Their R&D is all on line free. https://www.bbc.co.uk/rd/publications/rdreport_1992_10