Reducing impact noise from floor above studio

[Junction]

For xmas, I have bought myself a new house and will be setting up my studio in the basement, the ceiling of the basement is a typical wooden floor above. I will be installing a double layer drywall ceiling, not attached to the wooden ceiling joists, but will be attached to the 1 ft thick sandstone walls, to eliminate transmission from the floor above into the ceiling below it.

However I fear that I will have problems with impact noise of people walking on the wooden foor above. I do not want to cover the top side of the floor above with carpet etc. Would there be any merit in bonding something to the underside of these floor boards to kind off deaden the impact a little? I think I already know the answer will be "not really" because the impact will transmit into the joists. Any ideas???

Michael

 

[xmvlk]

Any ideas???

Heavy floating floor (some 5 tons of armed concrete would be fine if
structure of your house can it carry). Btw you can use it also for accumulation heating.

 

[TheGuitarist]

Lots of rockwool? cornig 705 i think its called, if you make it 40mm thick it should absorb alot of low end, the thicker the better.

 

[ChrioN]

Lots of rockwool? cornig 705 i think its called, if you make it 40mm thick it should absorb alot of low end, the thicker the better.

40mm isn't very much. maybe 120mm will do

 

[Svart]

The standard is to install two layers of 5/8(15.75mm) drywall under the floor, between the floor joists.  Caulk around the drywall to seal it between the joists.  then add some kind of high density absorption like mineral wool.  Depending on the design you may or may not add another layer of drywall hanging on resilient channel.

check out:

http://www.johnlsayers.com/phpBB2/index.php

for more than you'll ever need to know about building a sound proof room.

Rockwool/mineral wool is not the same as HDF(high density fiberglass) like OC 705.

Rockwool is made from basalt, HDF is made from silica.

rockwool is a lot cheaper too.

 

[Junction]

Svart you are right, kicking myself for not searching JohnSayers site before. Two de-coupled skins will work best, looks like I could get pretty good results with stuffing 16mm gypsum between the ceiling beams up against the above floor boards (like you said) and then two layers gypsum suspended below the ceiling above and not coupled to it, with insulation in the cavity. With this I should achieve an STC up to 58. Three layers top and bottom would be best, achieving an STC of 60, just costs a bit more.

This chart says it all: http://johnlsayers.com/Recmanual/Pages/STC%20Chart.htm

Cheers
Michael

 

[conleycd]

Impact noise the most difficult to manage.

Really and honestly you should consider carpet.  Impact noise spreds like wild fire throughout a structure - more so that air borne noise.

I'd also suggest Jeff Cooper's seminal task on building a recording studio.

Good luck.

CC

 

[Svart]

mass.

You are adding mass to lower the resonation frequency of the footsteps.  You are also increasing the amount of acoustical power that you need to move the same floor.  Consider adding "green glue" between the layers too.

 

[mitsos]

Speaking of mass, you could add that mass-loaded vinyl stuff to the equation. A bit pricey. Or you could go vintage and use lead.  

Aesthetically, carpet sucks, and it's possibly a health/allergy problem, but it would make a huge difference if you could deaden the footsteps a bit above the floor. But hopefully you can do without.

 

[Junction]

I guess all the treatment attached directly to the underside of floor boards really isn't going to stop the impact noise, I had this problem at my last studio and puting in a floating ceiling, not attached to the existing did help tremendously, but didn't 100% get rid of the high heeled shoes tapping up and down the floor above. This one will be in my house which was built in 1860 and floor boards are just the thing to maintain it's character, I really don't want to put in carpet or other floor covering. Maybe a hall runner rug in the main traffic areas would'nt look too out of place and will deaden those stomping feet a bit.

Cheers Guys.
Michael

 

[mpc3000limited]

Thats a tuffy, ;D honestly it is a structural thing. The only way to really beat it would be to build a floating room underneath.

But as that probably is NOT a realistic option most importantly strengthening all structural joist's by doubling every joist individually from supporting exterior walls (YES a major PIA but i have done it on a few houses) with a glue lam preferably screwed or nailed every foot sistered up. if you can properly do that I think that would be the first thing i would even bother doing before putting acoustic material in the cavities. Making sure any major supporting carrying beams are strengthened is not overkill at the basement level! After that you can mess with resilient channel and floating a ceiling. Still expensive but I dont know how much it bothers you. If i was staying somewhere for a long time i would do it right from the jump even if it took years to finish. my 2!

 

[machineintel]

I believe this is the solution you are looking for:

 

[Junction]

Machine, was that supposed to be a link? .... doesn't work
Cheers

 

[machineintel]

lame. should be fixed  ;D

 

[Junction]

LOL
Not sure I can keep those socks on the feet of my 4, 5 and 9 year old gilrs, but worth a try

 

[stickjam]

LOL
Not sure I can keep those socks on the feet of my 4, 5 and 9 year old gilrs, but worth a try

Oh, we're talking preschool-to-tween girls here?  That's my area of expertise.  Socks won't work.  Boots made out of Tempur-pedic thermoelastic foam won't even silence those feet of thunder!    Install a remote controlled red light in the room above and say, "one stomp when the light's on and the My Little Ponies (or Miley Cyrus DVDs/CDs in the case of the eldest) are toast!"

Seriously though, as mpc3000 alluded to, you need to consider the dead load capacity of the floor structure espec ially if you're planning on putting a lot of deadening mass up there (drywall, rockwool, etc).  Sistering the joists increases the capacity of conventional joists made from dimensional lumber.  If your house uses truss or I joists, you might be fine as long as it was sufficiently over-engineered.  Talking to a structural engineer may be a good move--I was fortunate, being related to one.  

Another consideration is headroom.  Adding a lot of layers of drywall and resilient channel will bring that ceiling down pretty far--uncomfortably so if you're on the tall side.  I had a drawing of how I did my ceiling--I'll see if I  can find it and post it.  It actually worked out quite well in the 7-foot basement of our 50's era house.

-Bob

 

[stickjam]

PS.  I just now noticed in your original post--you mentioned anchoring ceiling joists to sandstone walls.  I guess the only dead load you'd be dealing with is your ceiling material.  Are joists going sandstone to sandstone?  if not, you'll need to make sure the other end isn't coupled to the house--perhaps mounted resting on a separate wall structure isolated from other basement walls and the structure above.

 

[Junction]

Hey Bob, yeah my thoughts were to do some treatment to the existing floor structure above, which is very solid, I recall the joists are like 6" x 2" hardwood, spaced 2 ft apart. These are connected to the sandstone walls which are about 1 ft thick. Then I plan to put in another ceiling below the floor above, with joists spanning sandstone to sandstone.

So yes both layers will be fixed to the sandstone walls, but considering they are 1 ft thick, do you think there will be much transmission via the sandstone walls. I would'nt have thought so, but???

Michael