Sealing basement floor/walls? | John Sayers’ Recording Studio Design Forum archive

I've been reading this site for about two weeks now and there is a dizzying amount of information here. Thanks, very much. I now have a fairly good idea of how I'm going to construct my basement studio, although I'm stuck at the first step - to seal or not to seal the concrete walls and floor before starting, (two sides are poured concrete). I've read the various threads on this subject and have scanned the link to the Building Science Design article, but am still confused. Either I'm dumb as a nail, which is very likely, or something just isn't clicking. My basement is dry, on a walk out site so water is never a problem. I realize the nature of water in vapor form though, so I'm considering sealing the walls/floor with a good sealer prior to starting. Is this the right move? This one room studio has to be isolated as much as possible (and as much as my wallet will allow), so I will be floating the floor and walls, if that makes a difference with regard to sealing. Thanks. One more thing: Since I'm as cheap as the day is long, I am going to try to supplement the "real" sound proofing products with other materials to save a buck. One thing I'm considering using is a rubber truck bed mat cut into strips to be used as pucks to float the floor. Will that work or no? Again, thanks so much.

Hi, and welcome to the site - the first thing I need you to do, is to edit your Profile to include a location; this is literally a world-wide site, with members from all areas and walks of life. It's simply not possible to make valid recommendations without knowing what country you're from. As to sealing a basement - this gets even trickier when you're also trying to sound proof the basement. The first rule to remember, is ONLY ONE vapor barrier - even the type of paint you use can change this - latex paints don't generally act as an effective vapor barrier, but oil-based ones do - vinyl clad gypsum wallboard is DEFINITELY a vapor barrier, while paper clad is not. Plasticised plywood panels would likely be a vapor barrier, as are the heavier plastic based wall papers, etc - If you have a cooler climate that requires heating more than cooling, then you want your one and only vapor barrier to be on the frame just under your inside paneling - with double layer sheet rock, that would be right on the studs with both layers of sheet rock inside the barrier. This is because the warmer air has usually high moisture content, and when it travels through the wall to the colder area it takes the moisture with it. This then leaves the moisture inside the wall, and unless there is a way for it to dry it stays there and creates mold/fungus, etc. It's likely that your basement already has a vapor barrier, depending on location/construction/codes/age, etc - if so, then putting another one inside will only cause you grief. The basement PDF gives some ideas of typical construction methods here; it would help if you can figure out which of these your place matches the best. After considerable reading/thought on basements/studios, I've pretty much decided that the only sure-fire way to handle this is to build inner (single leaf, multi-layer) framed walls far enough inboard of the concrete so there is room for air circulation - this can be done without losing the damping effect of insulation contacting the inside of the wallboard, by mounting light boards (lath) on the side of the new stud frame closest to the concrete, so they keep the insulation from falling away from the wallboard after it's installed - Then, an access door to allow access to a dehumidifier and fan installed between the concrete and the new wall, left on and set to around 40% RH - the fan will help circulate air around the outside of the inner envelope, and if set on a low setting should be all but inaudible. You could also put both fan and dehumidifier on a separate circuit, switched by a light switch so you don't have to open the access door all the time. This way, if the fan/dehumidifier DO make too much noise they can be shut off while recording. Two things to watch in this case - remember to turn it back on before you leave, and don't buy a dehumidifier that has electronic controls; most of these default to OFF when power is first applied, so they won't work on a remote power switch. Nearly all dehumidifiers have a garden hose fitting so they can be left un-attended and still drain; this would need its own hole through the basement floor for drainage if you use it. If your basement is as dry as you say, the water should just go away once it's through the hole. This could be drilled with a 5/8" masonry bit on a 1/2" drill, somewhere near the dehumidifier's location, and a small garden hose run into it from the dehumidifier's drain fitting. Rubber truck matting is kind of an unknown variable; I have no idea what its Durometer rating would be so it's impossible to figure out what the effect. Choose wrong, and you build an AMPLIFIER instead of an ISOLATOR. Just one of the things to watch about mass-spring-mass systems. If you have some available, you might do the rudimentary tests I outlined here - http://www.johnlsayers.com/phpBB2/viewtopic.php?t=839 This should answer a couple and generate a couple DOZEN :? ... Steve Oh, please remember to edit your Profile - thanks...