John Sayers' Recording Studio Design Forum

Edited 6/15/2007 to include quick links to each individual page:

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Hello,

After sifting through all the topics on floating floors, I've got just a few more questions if someone has some answers.

1. Suggestion/recommendation on thickness of neoprene pads to use. 1/4", 1/8", 1/2"?

2. What density, or Durometer, or Shore is (which ever term is used) would you recommend?

3. I'm using 2x4 studs, (due to ceiling height), but I have concerns about moisture in the basement in general. Should I use normal studs, or pressure treated studs?

4. The subfloor I intend to use 3/4" material. Once again, if there is moisture, I don't want the floor to bubble or swell from using particle board. Will one layer work, or is 2 better?

5. Vapor barrier. Should I lay plastic directly on concrete, or use another material? Someone suggested using roofing felt. This would allow the floor to "breath"?

6. Over the years, I have often seen where they used sand in the floor. I've originally been planning to do this, unless the mineral wool is a better option.

Thanks,

Aaron

bump for me too!

here yah go...

1 - 1/2" neoprene
2 - Durometer of 60

3 - There is a thread in this forum with a link Steve posted regarding basement insulation techniques. I'd Read that for greater clarification n what you should do. I think it had it do with building your wall out from the basement and using the pink formular type insulation on the basement wall,etc... I am trying to recall from memory but search here for that info it is very good and enlightening.

4 - Two Layers is the way to go for stiffness and deadening of sound.

5. - Look at Number 3. Keeping that floor and those walls dry is the main thing. So study what this information can provide with regards to techniques to keep the basement aerated

6 - Mineral wool is a better option plus it is water resistent, mold and fungi resistant, etc....

Bryan Giles

Here's the basement article, I would save it to your hard drive and study it - it will take a few readings to catch all the points for your particular situation.

http://www.buildingscience.com/resource ... ystems.pdf

Read the article for your answers to vapor barriers, I don't recall the entire thing and refer to it myself regularly.

Durometer - 60 seems to be about the only thing available, 1/2" is deep enough to compensate for floor irregularities - if not, fix the sub floor before you float.

One thing few cover on floating floors - rubber is a spring. Springs ONLY act like springs when they are NOT at the ends of their travel. When they ARE at the ends of their travel, they are NOT resilient at all, and could just as easily be THROWN AWAY.

The only way I know of to be sure of the total amount of cross-sectional area of rubber you will need for your particular project (unless you're more of a mathmatician than I am) is to experiment - you want the total weight of ALL the floated stuff to cause the rubber to compress by at LEAST 15%, possibly 20 -

Edit, 3/26/05 - I've been meaning to update this part for some time, to reflect newer data - actual range of compression can be from 5-25% - the trade-off is between longevity and isolation. You get better isolation with higher compression, but lose serious lifespan of the material. For this reason, 10% is a good compromise to calculate for.

this includes EVERYTHING that will be supported by the rubber - floor, walls if they're floated on the floor, ceiling if it's supported by the floated walls, console, drums, EVERYTHING that is pressing down on that rubber must be figured in.

Find weight figures for all your building supplies, do a material list to find out how many of each product, do the math, and get a close estimate of what everything weighs. Include musical instruments like pianos, organs, mainly heavy items - and anything that's permanent, like console, speakers, glass, doors, framing, etc -

Once you find out what your total "sprung weight" will be, it's time to experiment. The way I would (will) go about this is to start with a very solid work bench - take a piece of your floor framing, oriented the way it will be installed (flat or on edge) and fasten a couple of pieces of lighter wood to the ends so that the framing piece is the center of a "U" - this will stabilize the piece so it won't fall over. If you're laying framing flat, don't bother with this step.

cut a small sample of your rubber, no more than 1" wide, and at least 1/2" longer on each end than your frame width. Lay the frame sample on the rubber, all resting at the edge of your sturdy workbench. You will need access to measure some things later.

Get a full set of encyclopedias, or some workout weights, something with a lot of mass - First, firmly push down on the framing sample so that you take any "slop" out of the interface between workbench, rubber and frame. Measure VERY accurately the distance between the framing sample and the top of the workbench, as close to the rubber as you can get. This is your "zero reference" - this is the thickness of the rubber WITHOUT compression.

Next, start stacking weights on top of the framing member, directly over the rubber, til you compress by about 20% - make sure the rubber is not constrained horizontally in any way, or the measurement isn't valid. In the case of 1/2" rubber, you would need to add weight til it was only .4 inches thick (measured between your framing sample and the top of the workbench) - Weigh the total material you stacked up to accomplish this, divide by the total area (in sq. in.) of contact BETWEEN RUBBER AND FRAME ONLY, and you have the weight per square inch that's necessary to accomplish 20% compression.

Divide your total estimated "sprung weight" by your "weight per square inch" figure above, and you have the total area of rubber to be distributed beneath your frame.

Allow for a few extra pucks under areas where heavy things will be - if you're using a serious console, put a few extras under where the legs will sit - same in areas where a piano will be. Allow for twice as many pucks around the perimeter and under any other walls. Don't add extra pucks, steal them from less rigorous areas and re-adjust the spacing.

You will probably find that laying frames flat will require too long a space between pucks for proper compression - If you need less floor height you can narrow the rubber pieces some, but watch getting too long a span between supports especially for flat laid frames.

I know this sounds like a hell of a lot of work, and it is - still, NOT doing this is kind of a Crap Shoot; you may get lucky, or more likely you'll be back wanting an easy fix for having taken the easy way out. There isn't one. Just because you're not a physics major (neither am I) doesn't mean you can ignore the laws of physics and get away with it - if you don't believe that, jump off a 10-story building while swearing you don't believe in Gravity... Steve[/b]

Giles117...In response to Q#3, the only portion of the studio that will have wood studs, will be the floor. The remainder of the walls, etc, will be done w/ metal studs (for several reasons). As far as the walls, there will be space left between the block wall and the new framing. Probably about 4". I have some moisture problems w/ water trying to come in. I've already spent several hundred dollars in attempting to resolve it, and hope it does the trick. I've rerouted all drainage from gutters away from the house, and have used Drylok masonry sealant on the block in the basement. So far, all appears to be working well, except where there is a small crack that has resulted from some blasting near by (widening the road).

I would love to use 1/2" neoprene, but I also have to be conscious of my ceiling height. My lowest point is 7' 3" (where the steel beam is). The rest is 7'10". So every inch is premium. At this rate, the floor alone will be 6 1/2" thick (I wish it could be more). Then I have the ceiling in addition, which will take up more space. Can I use 1/4"?

Thanks for the link, I have read this article and found it informative. That was part of the reason why I had so many more questions.

I intend on placing a dehumidifier in the basement, which is part of the reason for leaving the air gap around the studio and the concrete block.

As far as the double layers on the floor, not a problem, just the $28.00 a sheet price tag w/ 350+ sq. ft of space x2.

Knightfly...Yikes! Sounds like my wallet and bottle of aspirin have been sprung. I know it has to be done that way, now it's having the time. I don't suppose anyone has weights of materials handy?

Thanks,

Aaron

1/2" Neoprene is the way to go. Lay the studs flat instead.

And go for a shallower floor depth. Just make sure you have that insulation in there and you have the floor floated with 1/2" neoprene (I am getting repetitive)

You Will be fine.

As Far as what to use??

Do you have a Lowes Nearby? Try the ChoiceDek laminated wood decking studs. They are water resistant.

http://www.lowes.com/lkn?action=pg&p=Ve ... ml&rn=none

Bryan Giles

I can't lay them flat, due to having to run conduits for cables, etc. Should I lay some type of material down directly on the concrete prior to the neoprene, insulation and studs?

If you are dealing with water issues I wouldn't lay anything to cover the concrete directly.

How thick are these conduits? Try 1-1/2" PVC Pipe.

Most 56 or more channel snakes are well under that size.

Bryan Giles

I was planning to use 2" pvc. Maybe 3" in some area's (for multiple snakes).

I don't think I will have much of a problem w/ moisture. Just concerned w/ the concrete sweating, or condensation. It's humid here in the southern states.

We have the same issues here in Michigan. Detroit River next door, lots of humidity in the air so I feel yah.

The 1-1/2 was to get away with laying the studs flat

Bryan Giles

I would prefer to use the studs on edge. It will give me a thicker floor for isolation w/ the insulation, as well as running fewer conduits for cables. I guess my main concern is just keeping the floor off of the concrete. I guess I could just not use anything underneath. I was originally planning to put the sand in the floor, thus using a barrier for moisture, but if it's suggested I use the insulation instead of sand, that's the direction I'll go.

Should I use any acoustical caulk or anything around the outside, or leave it so it will breath? What about isolation from the other rooms? Will it travel under the floors cause problems?

The dehumidifier is a must, and it wouldn't hurt to use that basement article to thoroughly check out the rest of your location - see if there's any drainage things that can be incorporated, eave drains run out away from the house, etc -

With that much moisture, I would try to solve that problem before building anything more. You definitely want to build so that air drying can happen when things get wet. Pressure treated wood if it's in contact with concrete, don't use sand if there's moisture because it will NEVER dry out as long as the moisture is around.

On floor floating, there have been a number of people who've just built floating floors without all the measuring/math - some have LUCK, some don't but lie about it rather than admit a mistake, and some decide floating floors don't work because theirs didn't. The probable reason for the fairly high success rate DESPITE not knowing, is that anywhere from 10 to maybe 85 % compression will help SOME, so there's a big leeway for error and still have some benefit.

It takes longer to do the calculations (obviously) but it takes a lot of the "luck" out of it. Your call. I've been gathering info for a table of material weights, but it's nowhere near complete yet. A bathroom scale will help if you have the materials handy, in fact that's one of my next plans when I visit Home Depot with some time...

Here's a bit of a start, at least for drywall -

Regular Drywall Panels.

Panel Size - Weight - Lbs/SqFt

4' x 8' x 3/8" = ///45 lbs. //1.406
4' x 10' x 3/8" = //56 lbs. //1.406
4' x 12' x 3/8" = //67 lbs. //1.406
4' x 8' x 1/2" = //54 lbs. /1.6875
4' x 10' x 1/2" = //68 lbs. //1.6875
4' x 12' x 1/2" = //82 lbs. //1.6875
4' x 8' x 5/8" = //74 lbs. /2.3125
4' x 10' x 5/8" = //92 lbs. //2.3125
4' x 12' x 5/8" =//110 lbs. /2.3125

Firecode Core Panels

4' x 8' x 5/8" = /70 lbs. /2.1875
4' x 10' x 5/8" = /88 lbs. /2.1875
4' x 12' x 5/8" = /105 lbs. /2.1875

To convert lb/cu ft into kG/m^3, multiply by 16.04. To convert the other way, divide by 16.04.

Concrete weights approx. 3600 lbs/cu yd when cured, about 3900 pounds wet.
133 lbs/cu ft, or 2133 kG/M^3 -

MDF - approx. 68 pounds per ½” 4x8 sheet or 2.125 PSF, 53 PCF.

Glass = approx. 3.58 times weight per unit thickness of sheet rock - roughly 161 lbs for 4x8 sheet of 3/8” glass. 161 PCF, or 2576 kG/M^3 -

The surface density of ¼” plywood is 0.74 lb/sq ft, or 23.68 pounds per 4’x8’ sheet.

The surface density of 3/8” plywood is 1.11 lb/sq ft, or 35.5 pounds per 4’x8’ sheet.

The surface density of ½” plywood is 1.48 lb/sq ft, or 47.36 pounds per 4’x8’ sheet.

The surface density of 5/8” plywood is 1.85 lb/sq ft, or 59.18 pounds per 4’x8’ sheet.

The surface density of ¾” plywood is 2.22 lb/sq ft, or 71.04 pounds per 4’x8’ sheet.

A dry 8’ 2x4 weighs about 10 pounds, 2x6 about 15.7 pounds; density about 4.28 PSF for 2x lumber. This puts 2x lumber at roughly the same density as a layer of 5/8 and a layer of ½” drywall.

Celotex has an average density of 16.8 PCF, or about 39% as dense as gypsum wallboard.


As far as your project, I'd strongly recommend taking this slow and thorough - moisture problems have completely rotted out construction in a couple of years... Steve

Hence my resoning for recomending you look into that choice deck. As it is plastic encapsulated wood. So rotting is a dead issue.

Bryan Giles

Bryan,

that might cover rotting - but it does not cover the health problems (some of them deadly in fact) associated with mold issues....... and dark damp areas are perfect conditions for this.........

The last couple of years there have been some serious studies indicating that this is a much graver health threat than has been previously thought............ so i would not discount this easily..........

Before anyone begins construction in a basement with moisture problems - maKE certain the problem is solved (in one manner or another) prior to closing anything in.

Rod

Thanks for the insight Rod. Never considered the severity of the Mold issue. So what can he do to solve this/plan for prevention?

This is especially a concern for older construction. Any additional insight on how to build in a basement as well? Especially wall construction to allow the basement to continue to breath.

I'd like to know as well. When I am complete with the 1st floor Studio, I plan to gut the basement and build a 5.1 mix room in the basement.

Bryan Giles