soundproofing my floor (his ceiling)

[krabapple]

My new downstairs neighbor (we both own, in a small apt building in NYC; I live on the top floor) plans to do a gut renovation of his floor before he moves his family in. It's an old building, predating concrete-slab construction, and when he guts his floor, from his POV he'll see the big wooden beams holding up my floor, and the underside of my floor. That's all that's there.

He and I are on good terms and I want to be a good neighbor (the last owner was his brother, who didn't have a family and didn't care about noise from me). I was thinking of offering to pay for sound-insulating his opened up ceiling, prior to him having new ceiling drywall installed, if it could help significantly reduce downward sound propagation from my floor to his (I have a 5.1 setup).

I realize that *completely* blocking bass requires serious mass (like...a concrete slab), but I could still aim for substantial reduction in sound. Is this feasible, and if so, what materials/construction would serve best?

 

[Alex2507]

I've seen a few really good threads on the topic here and there but the links on this page should give you some options for a few applications.

I want you to move in upstairs from me and pay some of my bills.

 

[Tubamark]

Whatever you do, the thing that makes the greatest difference is having that new ceiling resiliently suspended. Impact noise thru a structure is very difficult to stop with just mass. A concrete floor will even transmit impact easily if the flooring is hard and laid directly on the concrete.

Insulation in the joists is a no brainer. Always add that, if not there already.

It is also important to make it airtight; a surprising amount of airborne sound can get through in some types of construction. If your neighbor currently only hears impact noise-- footfalls, etc, then this is probably not an issue. If he can hear speech or typical level television thru the floor, you likely have some airborne sound leaks. Resilient caulk (cures flexible, non-hardening), etc will fix most situations.

--- Mark