Soundproofing Assembly Above Round Timbers
I am working on the second floor loft of our home. We would like to soundproof this as much as possible as this room will be enclosed into a bed, but I’m not finding any tried and true assemblies for this because of the unique joists. We would prefer not to hire an acoustical engineer. I have a few ideas which I’ll detail but I’m wondering if anyone here has some advice. We are musicians and my husband is a luthier so we are somewhat familiar with sound.
The essence of the issue: See image. The log joists are flat on top and round below, so there is not layer of drywall on the ceiling below that we can use in combination with a hat channel. We can certainly insulate from below (in between the logs) and put some sort of finished ceiling in between logs such as shiplap. Due to the low loft ceiling, we would like to avoid raising loft floor up too much.
My idea: In between ledger/cross beam and floor joists (anywhere there is wood to wood contact) put in felt or cork or some sort of damper material. On top of logs, before subfloor, also lay damper material. I haven’t decided yet but I’m thinking 1/2″ rigid cork board. (Not sure how much better that is than fiber board.) These come in 2’x3′ sheets and spacing of logs is 16” center to cetner so there will probably be gaps in this layer that we have to fill in from below. And we will have to make sure there are no cracks is my understanding. Then plywood, then either cork flooring or another layer of soundproof underlayment then wood floor. One drawback I’m seeing of cork floor is that it’s easily stained with spills and has to continually be refinished for waterproofing. We aren’t fastidious with liquids. From below, in between logs, we can insulate before adding finished ceiling material such as shiplap, but not sure if that is any better than adding an air space. Especially since most sound will be transferred through logs.
Any advice on this system would be great!
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