Minimum Ceiling Height in a Wee Basement

Davy Crow · Post by **Davy Crow** » Thu Dec 16, 2004 11:05 am

hello people....

just got a 2 floor premises, ground floor and basement, under a block of residential flats.

height in the basement is about 6'3 (the tallest of the 4 of us - its just for private use - is about 5'8 )

cant remember what the length and breadth is off the top of my head but the ceiling and floor is the main unanswered question in my mind. i reckon we have enough space all round to make the walls 2 sheets of plasterboard onto 2x4 studs filled with rockwool or other then an air gap in between and the same again, just like one of the diagrams i seen on a link from here that shows 63db stc.....

so for the floor i was thinking a layer of sand 1.5'' thick and then 2 x 4 joists to lay a floating floor on top. not sure what the best flooring to use is but if it is floated then i am thinking half inch laminate floor would be ok? thus giving us the ability to rug or de rug as the acoustic desirables dictate...

for the ceiling we have been debating how to keep it as high as possible, whilst still keeping it seperate from the structure to making it a room within a room?

the rough layout of the studio is basically a rectangle area with 3 sections, drum booth to the right, live room middle the control room left so in the drum booth we can afford to lose height and have the back wall, which is nearest the busy edinburgh road outside, as thick as we need to keep the sound getting to the pedestrians. their will be internal windows for vision from one end to the other.

at the end of the day we need to be able to crank up marshall valves and hit various drums whenever we want so its imperative we do it the right way 1st time. like many people were sickened by moaning neighbours who should have a little respect for people trying to play live techno at 5am on a 500w power amp. instead though they tend to choose the easy way out calling on the bobbies.

anyway any advice on how best we can build that box and remain anonomys whilst not developing hunches would be very much appreciated.

thanks in advance.................

this is a quality site, learned loads from it

oh aye i forgot to mention that we plan to soundproof the ground floor as well when the studio is finished, that has no ceiling height probs

cheers

dc

Davy Crow · Post by **Davy Crow** » Sat Jan 08, 2005 3:50 am

Firstly a Happy New Year to all of you crazy people........

my only question here really is how best we can do the ceiling, keeping height loss to a minimum.

we actually have just under 6'6" from floor slab to the bottom of the ground floor joists.

weve had things pretty loud at 2am just in the shell of the basement with no complaints although when we get a kit and a marshall valve amp going it will be considerably louder than a few drum machines.

through reading this site we sort of have a good idea of what needs to be done but if anyone has came across a similar situation, all advice welcomed. as i say our only concern is how to get good soundproofing done and save on ceiling height.....

we look forward to making a deserved donation to this cause.

knightfly · Post by **knightfly** » Sat Jan 08, 2005 9:00 am

Davy, it's gonna be tough to do with that low a ceiling; first, floating a floor successfully takes more headroom than that; you need more mass than 1/2" flooring, and more air gap than 1-1/2" (even filled with sand, although that will help) to keep drums and bass under control.

One thing you may want to do instead, is to just do a taller (more air gap, thicker floor) floated RISER for the drums, and probably the bass amp. This would save headroom everywhere but the drum area.

About the only way for a ceiling is to hang a couple of layers of gyprock on something like the RSIC clips,

http://www.silentsource.com/rsic.html

If ceiling height is REALLY critical, these can be mounted up on dummy "cross joists" on the sides of the ceiling joists so there's just enough gap NOT to have the ceiling channels touch the joists - the space between upper floor and lower ceiling should be filled with rockwool or mineral wool or glass wool, somewhere between 3 and 6 PCF (48 to 96 kG/cu. meter)

If this doesn't make sense, I'm kind of pushed for time; post back with any other questions, or for a clarification of this... Steve

Davy Crow · Post by **Davy Crow** » Mon Jan 10, 2005 3:02 pm

thanks for replying Steve, great help...

i reckon those RSIC clips are the boys for us.

we will definately need to go with the idea of having a smaller height drum room where it wont matter all that much about the height.

in our guitar and control rooms do you reckon we will get away with 1/2" neoprene with 4x2 joists on top with rockwool or sand in between then 1/2" or 3/4" flooring on top?

since we have commercial properties on either side of us it is only really sound getting 2 floors above our basement that is the concern. would having a less sound proofed floor construction defeat the purpose of building walls and a ceiling which contains the noise?

once again your time is much appreciated.

Davy

knightfly · Post by **knightfly** » Thu Jan 13, 2005 2:54 am

Davy, it's hard to be sure without more detail on your construction - but there's a good chance flanking noise could get you without a full room-in-room setup - it would partly depend on how "live" the existing floor is, and how well it's coupled to the walls, etc - if you have a solid un-broken transmission path through structure, the sound will follow that path and re-resonate anywhere there's a sympathetic panel, on any floor, sometimes 3-4 rooms over to the side, etc - the ONLY way to make sure this doesn't happen, is to decouple EVERY surface that sound will be "attacking", so that sound doesn't get the chance to DIRECTLY excite the outer structure of the building. This means floated floor, resiliently mounted inner walls, resiliently suspended ceilings, all with enough mass to keep m-a-m resonance as low frequency as possible.

If you're NOT already on the bottom floor, with earth under concrete, it's also a good chance you can NOT put enough mass to make the floated room thing work, without causing a cave-in and possible injury or death.

I'm not trying to sound like Doctor Doom here, but I also don't want to make light of what's necessary to kill sound, and then have you be disappointed and broke and making rude remarks about my parentage... Steve

Davy Crow · Post by **Davy Crow** » Sat Jan 15, 2005 4:48 am

hey steve,

aye man were basically building on top of a raft foundation so we are basement with the worms as our 'downstairs' neighbours then we have our ground level room above us (after studio construction will be constructed into a bar

) so theres no worry about any worms being upset with the techno booming in our box.

the buildin plans we have are going with the uncoupled way of thinking. keeping it strictly room in room.

hopefully the floor plan i have described above will provide enough mass to keep in the sound.

thanks for your advice steve, certainly no question in my mind of your parentage!!!

LemonAudio · Post by **LemonAudio** » Sat Jan 15, 2005 10:54 am

Davey, get on to Travis Perkins for your rockwool. Cheapest in Scotland. They have a branch in EastKilbride that deliver. Timber and gyprock (the thick 16mm soundcheck) is also the best prices I've found.

Their rockwool is Knauf Rocksil RWA45, equivilent to the owens corning 703 you hear mentioned around here all the time. 6 slabs of 1200mm x 600mm x 50mm in a pack for £19...covers 4.3 meters squared. £10 delivery on any size of order

Unit 1 peel park place
Eastkilbride

tel: 01355 242 306

Good luck mate

Alec

knightfly · Post by **knightfly** » Sat Jan 15, 2005 2:22 pm

Hey Alec, thanks for contributing the source; could you also put it over in the materials forum, so others from yer neck-o-th-woods can save some headaches? Thanks... Steve

Davy Crow · Post by **Davy Crow** » Sun Jan 16, 2005 2:11 am

quality mate, cheers fur yer help....

know anything about scottish arts council grants? ie how to go about saying the right things in your application?

Davy Crow · Post by **Davy Crow** » Sun Jan 16, 2005 6:31 am

steve, one last question on the subject of the floor.....

we just have a concrete foundation on which we are building our studio, will it defeat the purpose to just have 2" joists instead of 4" ones?

will this size of air gap be too small and make our efforts elsewhere worthless?

the plan for decking the place is 3/4 ply with 1/2" laminate flooring on top, of course caulked to the max...

as you mentioned previously, de-coupling is crucial, which we will be bearing in mind and doing as much as possible.

we plan on putting a layer of neoprene down onto the concrete foundation before the joists go on top, air gaps with rockwool.

i hope i have put this across in a non confusing way.

LemonAudio · Post by **LemonAudio** » Sun Jan 16, 2005 9:42 am

Dave have you thought about treating the floor above the basement to save your head height?

floor boards up, rock wool betwee joists, some mdf on the joists then a layer of soundcheck gyprock then put the floor boards back down. Might have to plain a bt off the bottoms of your doors but its an alternative

Also, sorry, dunno anything about sponging money from the council....I'm in Glasgow...not Edinburgh

Knightfly...already had it posted

Alec

Davy Crow · Post by **Davy Crow** » Mon Jan 17, 2005 1:19 pm

aye man we have thought about sound proofing above us which we will do so we can have loud parties in our bar on the ground floor

thanks for the suggestion. the trouble im thinking of is with flanking noise, structure borne sound waves that creep up on old grannies and people with babies and make them call the busies. thats not what we want in china town, busies not welcome!

and about sponging from the council, the scottish arts council do what they say 'on the tin' - council the arts in SCOTLAND.
that might look a bit sarcastic but what im saying is that its worth looking into, the scottish exec gives the council lots of money every year to fund arts projects across the country and although i havent a clue what you are up to, i suggest having a look on their website.
regardless of what your doing, funding, im sure, will be welcomed.
unless of course your loaded, in which case i suggest you leave the cash for some 'less fortunate' people

knightfly · Post by **knightfly** » Fri Jan 21, 2005 4:30 pm

Hey Davy -

we just have a concrete foundation on which we are building our studio, will it defeat the purpose to just have 2" joists instead of 4" ones?

will this size of air gap be too small and make our efforts elsewhere worthless?

Not worthless, but less - probably about 6 dB worse at the "thump" end of the frequency range, since you'd be cutting your air gap (the "spring" part of mass-spring-mass) in HALF - this would raise your m-a-m resonance by at least 20 hZ, which is always bad.

we plan on putting a layer of neoprene down onto the concrete foundation before the joists go on top, air gaps with rockwool.

Now, the (maybe) GOOD news, especially fer yer famous Scottish thrift - you do NOT want the entire floor covered with neoprene - in fact, unless you plan on dyin' within the next 10 years, you should find EPDM rubber, 1/2 to 1 inch thick, 60 durometer hardness - you cut small pucks from this, about 1-1/2" x 3", and space them far enough apart so that your joists only compress them by 15-20% - there's a thread here where I describe a poor man's way of calculating this -

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=839

Further down the page there are some typical weights of building materials to help figure out total weight, which will also depend on whether you suspend your ceilings from the above floor joists or add a new ceiling frame to your floated walls/floor, and hang the ceiling from that... Steve

Davy Crow · Post by **Davy Crow** » Mon Jan 24, 2005 3:47 pm

hey steve

thanks again for the advice, it is good news about the neoprene and although we worked this out before, i confess it was the original idea that the whole floor had to be covered in the stuff. been spending many a night neglecting my desire for sleep to ingest all the information i can find on this.

on the subject of thrift, my vocabulary didnt extend to such a word as that so i looked it up and all i could find was references to 'urban myths'

beats me!! i stopped there cos i dont know what an urban myth is either...

cheers again

knightfly · Post by **knightfly** » Thu Jan 27, 2005 10:34 am

Urban myths are just that; a myth.. sooo, it would follow that if they don't exist there probably isn't a definition fer 'em

So yer tellin' me you never heard of the Scotsman who was set upon by two thieves, proceeded to beat the tar out of both of them, then their friend gets him from behind - after checking out his wallet and finding only 6 pence, one of the thieves commented "if he'd had half a crown, he'd - a killed us all"...

Oh well, mighta been somebody else

Steve