After years of saving, we just completed a two-story addition with a large family room on the first floor and two bedrooms on the second. Unfortunately, something –I think it is the deep Lightolier recessed lighting cans in the ceiling of the family room — is transmitting sound so clearly from the first floor to the bedrooms above that someone in the bedroom can hear a conversation taking place at normal volume in the family room below. I have lived in cheap apartments with better sound insulation between floors than in my new addition.
The second floor rests on 14 in. deep, 20 ft. long laminate I-beams. The subfloor of the second floor is composed of 3/4 in. plywood topped by 3/4 in. pre-finished maple, which should deaden some sound transmission. There is R30 insulation between the two floors except where the cans (there are 16)are located. There are no HVAC ducts in the ceiling of the first floor or connecting the two floors. I can hear the sound most clearly when I place my ear to places in the second story floor that are directly above the location of the cans in the first floor ceiling.
The architect says that he has never heard of such a problem before, but he can sure hear it now. The builder said the sound transmission problem would disappear when we put in rugs and furniture, but it hasn’t. My questions are:
1. What is causing this problem?
2. Can I fix it? The architect suggests replacing the cans with insulated ones and possibly putting blown-in or rigid insulation above the cans. There are two drawbacks: (1) it would be quite expensive and would require extensive drywall repair (cutting and patching squares around 16 cans and (2) it might not work. In addition, the insulated cans must use lower wattage bulbs.
Does anyone have any experience with this type of problem? Does anyone have suggestions on how to fix it? I am hoping for relatively inexpensive solutions but am open to anything that is reasonable certain to work.