Insulation, Radiant and Vapor Barriers - Basement Ceiling - R11 good enough?

I am finishing basement. Ceiling Joists 2 X 10 on 12" centers. Basement has heat. I want to insulate and get some sound proof as well. Local Insulation supplier can get me 12" wide R11 or 12" wide R19.

The R19 is about $250.00 more.... I know it much thicker and has better insulation but just looking on opinion on wheter its worth the extra cost.
Thanks, FF

Since you are putting insulation between two conditioned areas the amount of insulation value is not important. The extra insulation will not save you any money.

The sound attenuation difference between the two choices is very little, so I would go for the R11 considering the price difference.

I would definitely use 5/8" sheet rock on the ceiling. If you are really worried about the sound, you could go with 2 layers.

Dick

Thanks for the advice.

I meant to say R11 verses R19..... if it makes a difference.

I must say I cringed whaen you said 5/8" rock on the ceiling and double it..ouch!

Speaking of rock...... I noticed 1/2" and 5/8" were the same price at Home Depot today. What is the benefit going with 5/8"..... I see you mentioned sound deadening effect is there other benfits?

Thanks for the reply, FF

Mass or weight is one of the best barriers to many types of sound. If you had a solid concrete floor, you would not be cocerned about sound.

The thickness of the sheet rock depends on how far you want to go. Double rock is probably a little much, but if you are putting it up, it is just a little more material and still only one layer to mud.

Dick

Insulation between the joists is a very good start to sound proofing. The idea is fill 3/4 of the ceiling cavity...you do want to leave a some air sapce.

To improve even further, you should consider adding "resilient channels" along the joists. This is one of the best methods of sound proofing as it seperates the drywall from the joists, therefore sound vibrations do not transfer.

Most insulations cannot handle anything below 400 hZ - but since it's through a floor system, most of the sound will be below this threshold. For the same money, you get better performance from increasing the amount of sheetrock vs increasing the amount of insulation. Double drywall is a brilliant start.

Resilient channel is a nice touch, but for the same money it may be a better idea to do a ridiculously good job of soundproofing your floor vents. No matter how well you do the ceiling, floor vents are a big giant hole in your sound armor.