Soundproofing basement

[BMT5000]

I am setting up shop in my basement and need some soundproofing help. The floor is sloped concrete, the walls are cinderblock. The ceiling is open, just joists with rolled insulation between them. I put some acoustic ceiling tiles on the walls to help, but am looking for help with the floor, ceiling and other ideas for the walls. The room I am setting up in is below the living room so it is hard for my wife and newborn to hang out with the constant whine of the dust collector.

[SteveHall]

I'd recommend gypsum wall board (GWB) on the ceiling joists as a great first step. The combination of its mass and enclosure will reduce sound transmission much better than the insulation and is relatively inexpensive. Plus it will improve your lighting and cut down on places for dust to reside.

Another concept is to insulate the sound generating devices themselves, a rigid foam and/or GWB shell around a dust collector requires much less material. You have to make sure there is enough air circulation so the motors don't overheat as well as ensure easy access for maintenance.

To improve on that would require separating a new ceiling mass from the floor joists by hanging a GWB ceiling on steel channel, thereby reducing transmission from the GWB directly through the joists.

Then beyond the point of diminishing returns are incremental solutions like adding mass to the floor system above such as putting down tile/brick/stone (ensuring the joists can handle it of course!), replacing the fiberglass with improved acoustic bat, adding an active cancelation system, etc. Also, solutions like ceiling tile on the wall probably help cut down reverberation, but not too much with the peak volume of sound going through the floor.

My $0.02.

[McRabbet]

Brian,

Probably the best solution (although not the cheapest) is to install a suspended ceiling, dropping it no more than 6 inches below the joists and piping that is shown in your second picture. You'll need to frame in around the HVAC duct runs where they are lower than the drop ceiling would be. You'll need to lower the smoke detector, too. If done with T-track hung on wires, it should be a good sound barrier when the acoustic tiles are installed. If you lay fiberglass batts on top of the tiles, you'll have a very good acoustic barrier. I plan a suspended ceiling when I can afford one, but I do have 2' x 4' drop-in 4-bulb T8 fluorescent fixtures (troffers from BORG for about $45 each, made for suspended ceilings) hung on chains. I have 6" fiberglass batts in my shop ceiling joists and it cuts the sound by 90%, even though they are exposed like yours.

The second method is to attach Z-strips -- also known as resilient channel -- to the bottom of the joists and then attach a ceiling to them. The ceiling can be drywall on 2 x 2 furring strips attached to the Z-strips of an acoustical tile ceiling. The Z-strips isolate any vibrations through the new ceiling to the floor above. Make sure you do not have any vibration-carrying items tied to the floor joists above as they will make the floor vibrate and carry sound through.

Hope this helps...

[Mark Anderson]

isolating the vibrations as McRabbit has said is the key to soundproofing. alos adding more fiberglass may help. if it is insulated to code it only has 6 inchs of insulation and you can fit more.

[Travis Porter]

Looking at the area you are setting up in and the way your plumbing and electrical are run, I would go with a drop ceiling like rob suggests if you have the head room. If you can get away with it add some fiberglass insulation on top of it as well to help absorb the sound.

[mtrager]

I recently finished my basement shop - I went to Tucker Materials just south of Asheville - they specialize in drywall and soundproofing. After much discussion, they convinced me to put fiberglass insulation between the joists, then put up 4 x 8 sheets of a 3/4" soundproofing board and then 1 or 2 layers of 5/8 drywall (I used only 1 layer). Tucker also sells the resilent channel as mentioned above but they thought this was my best bet.

It worked out great. The shop is under the Master Bedroom and my wife says she barely if atl all hears the equipment.

If you have the headroom the suspended ceiling also mentioned above is the presumably the "best" way to go.

[BMT5000]

Thanks McRabbet, I think I will try the drop ceiling w/ added insulation. We will see how it goes!