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Exposed insulation question with a twist

Hey guys, I have a basement that I am only PARTIALLY finishing for sound proofing reasons. There is a small corner of the basement that I sectioned off and wish to install a ceiling for soundproofing reasons only (drum set). I am on an EXTREMELY tight budget and I believe I made a mistake in going out and spending $60 on sheetrock and Pink backed fiberglass insulation. I didn't realize at the time that the fibers can come loose, and now I am trying to figure out if it'll be safe to use this stuff or if I wasted 20 dollars (can't return it).

I read a few posts about covering exposed insulation with 6mil plastic, but I have two issues with this. First issue is that I won't be installing ceiling on the entire basement, so the edges of the insulation will still be exposed.

My second question is, if fiberglass fibers are just going to fall off and accumulate on the plastic, isn't this going to cause a problem eventually anyway? I mean over the course of a few years, all the dust that would have been on your floor will be settling on top of that plastic, and unless that plastic is perfectly sealed against something isn't it going to find its way eventually anyway through drafts or what not? Could I completely wrap each section of insulation with plastic? It's not a moist basement by any means, it has always been bone dry down there but it is still a basement in the North East so I don't know if sealing the insulation completely is a good idea.

Thanks in advance!

Re: Exposed insulation question with a twist

Just to add to the confusion, I have been researching some recycled denim insulations such as Ultra Touch. They seem to be a lot safer than fiberglass, but I really haven't heard anything about them being dust free. Having them stuffed up in a not fully finished ceiling area that can't really be sealed, if they emit the same kind of dust that the pink stuff can over time it would still be just as bad to me to have to be cleaning blue dust off of everything even if it were less harmful. It's definitely an option, but still not really a solution.

Re: Exposed insulation question with a twist

n the northeast putting fiberglass batts between the basement ceiling joists with 6 mil polyethylene on the underside to hold it in place can create near perfect conditions for fungus to grow on the lower edges of the joists. Insulation alone or with sheetrock or or house wrap to hold it in shouldn't be as much of a problem if the basement is unusually warm in summer or if you run a dehumidifier. If you use paper faced fiberglass the paper side should be on top toward the underside of the floor.

As for the fiberglass dust. I itch for days after handling the stuff, but it its that hard to seal off well enough with sheetrock , wrap, or wood. At the end of the "finished" area the covering should be fitted between the joists and extend to the subfloor. So the dust is only a problem when it's installed and if it needs to be disturbed for repairs or renovations.

The cellulose products are pleasant to work with and are better at soundproofing than fiberglass.

Drywall attached to resilient metal channels with cellulose above provides good soundproofing but isn't a low budget job.

Re: Exposed insulation question with a twist

I wish you'd have posted before purchasing anything. I have set up an in-house recording studio/band practice room in a garage and you could hardly hear anything 50 feet from the house, and it was all done for almost nothing in cost ;)

The fiberglass covered with sheetrock will be OK on the ceiling but not when used in the normal manner. Use no plastic or vapor barrier here. Use unfaced fiberglass (or tear the paper facing off) and stuff it between the joists. On top of the joists apply strips of 1/2" styrofoam cut from a sheet of wall sheathing like R-max (or from wherever you can find similar styro) then screw the sheetrock in place. Push up hard on the rock when screwing and stop the screws at the surface (or as shallow below flush as possible if you're going to finish it) and be sure the rock touches nothing else. This will help isolate sound transfer to the joists. Rolling on a thick 'texture' coat of sheetrock mud will also help break up sound waves and it's weight will help deaden vibrations. Block off the ends of the joist bays to contain the fiberglass with r-max caulked into place. That will do OK for the ceiling. You'll still need to do something for the sides of the area.

Cheapest but not code-legal is to use heavy rugs or old carpeting for the sides. Note that this violated fire-codes for flammability so at least put in a loud smoke detector. You roll them onto scrap wood strips, attach them to the sheetrock (again not super-tightly but securely) then let the bottom [email protected] the floor by a few inches. This should be free-hanging, not attached to any walls.

If you go for sheetrock walls later on isolate then from the floor and ceiling with styro and don't push the ceiling sheetrock tight in the process. Fiberglass between stud bays (you may use a vapor barrier or paper-faced rock normally) then staple unfaced fiberglass wall insulation across the back of the studs horizontally, shoving it in somewhat tightly top and bottom. It will compress at the staples but let the rest float. Block off the ends with styro like you did the joists overhead to contain any fiberglass dust. Be sure those walls touch nothing too or they will transfer the sound. Best is to caulk, not tape and mud, where the walls meet the ceiling and floor. Again roiling on a heavy mud texture will help. And believe it or not, old egg cartons make for an almost lab-perfect anechoic wall and ceiling covering!

The principles of sound deadening are to absorb sound through mass, break up harmonics though low density materials, and to have that mass not transfer the movement to anything else.

Remember- none of this except studs and sheetrock meets firecodes so you're on your own there and if you choose to do this, be extremely fire-safe in the area: no smoking, no candles, no heaters, and when your session is done cut all electrical power to (and behind) the area. Then go back and check about 5 minutes later just to be sure nothing is smoldering. Have an escape plan in case of fire and be sure that everyone who enters the studio knows it.

Keep the beat!

Re: Exposed insulation question with a twist

Ok, I had a long reply here but I just deleted it as I have been staring at the ceiling all day (literally) trying to think of what I can do.KShenefiel, What you said about the moisture/vapor retardant was very helpful and Mastercarpentry, you're write up on sound proofing gave me some awesome ideas.

I think I CAN go above the pipes. I didn't realize how much wiggle room there was, I'd certainly be able to screw in some lower hangers and bring the pipes down enough to sheetrock right to the joists...at least for most of it. There is one area where there is a large dryer exhaust pipe that I'll have to get creative with . Mastercarpentry, the basement actually DOES have sheetrock walls. It's actually a room in a room, and I'm building sort of another room in that. There is a large room with sheetrock, then an area outside of that with the boiler/dryer/washer/hot water heater that is unfinished. The area I am sealing off is about 7x9ft total and basically a little cutout in a finished room (finished as in walls but no ceiling) with 3 walls and then the 4th I will be using soundproofing blankets on hooks to section off the area from the rest of the finished basement area. . I own the blankets already and they work great, and i'll be able to remove them to have full use of the room when not using the drum set. I also have about 50 sq feet of wedge-style 1" soundproofing foam that I'll stick around the walls and ceiling.

So my idea now is, using your advice, install the insulation between the joists then install styro and sheetrock over it (finishing it off by capping the ends with styro and caulking). I believe I am going to scrap the Pink stuff just incase I can't do as good of a job sealing it as I'd like or if I ever need to take it apart. Don't need all that fiberglass dust in the air plus the recycled denim stuff should soundproof better.

Right now, my main question is whether or not the styrofoam acts as a vapor retarder? If using something like Ultra Touch recycled denim insulation, will I run into a moisture problem installing stryo and then sheetrock over it and sealing it all up?

Thanks again for giving me some direction and ideas!

Re: Exposed insulation question with a twist

To some degree, the styro panels closing in the insulation will trap moisture but unless you've got a humidity problem down there already I don't think it will be an issue. Note that I'm not talking about doing a whole ceiling/under-floor area, but one where the areas past the sides are open or at least not covered. With the new info you posted, I'd say that a totally free-standing room would be the best route if you can do that within the existing headroom. Leave the door open when you're not using the space and everything should be OK.

Also keep in mind that no matter how well you contain the sound, inside that room you aren't exactly emulating real-life stage conditions (ask a sound tech about 'pinking in' a room) so you might get a more realistic non-laboratory sound by leaving one or more walls bare or partially so. On the room I referred to we had a knee-wall with insulated glass above separating the mixing console 'monitor room' from the 'stage room', and that wall was bare on the stage side. We hung a couple 'runner' sized rugs at the ends to reduce the 'bounce' and the window was soft-set with masses of silicone supporting it so it didn't resonate. That set-up gave that room a sound similar to playing in a small bar. If you know or have a good sound man, now's the time to get them involved.

And don't forget to protect your hearing. Too many years of too-high music volume has left me so tone-deaf (and deaf in general) that I've lost a lot of the pleasure I used to get from listening to music. I just can't hear it like I used to no matter how loud I crank it up, and I don't want anyone else to suffer my fate.

Re: Exposed insulation question with a twist

If you have the the head room it would be better for sound control to frame in a drop ceiling with 2 by 4s. If it's several inches out of level to avoid a duct at one end that would be even better for sound quality.

The moisture issue i was concerned with tends to occur when windows are left open on the main level of the house on humid summer evenings. The water vapor passes though the floor boards and insulation between the joists and is trapped by the plastic on the cool basement side of the insulation; where if the basement area is well below grade and insulated off from the rest of the house the temp can easily be near or below the dew point.

polystyrene foam is a vapor retarder not a vapor barrier. It is many times more permeable than 6 mill poly as long as it doesn't have an unperferated foil or plastic facing. The white beaded foam is the most permeable but the blue or pink extruded foam would also be fine. Insulation on the underside of joists can help prevent mold problems within the floor but you'll still want to leave the room open when not in use so it doesn't become a cold dank corner in an otherwise warm dry basement.

It may be a hassle to get denim in small quantities. For the size of the area you are doing you could get a few bags of loose fill cellulose and pitch it on top of the drywall or foam by the fistful as you put up the drywall.

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