Insulation for New Shop

[Tyler Schroeder]

I'm currently in the process of building a new shop, and am fast approaching point where I need to choose a route to go for insulation. The new shop is about 15 feet from the neighbors house, and most of my shop time ends up being in the evenings, so having good soundproofing is important. I was originally planning on going with dense-packed cellulose, but an insulation contractor I spoke with said that blown in fiberglass provides better sound proofing and cellulose can have some settling issues. Anyone have any insights into which might be a better choice? In addition to the insulation, I'll be applying a double layer of 5/8 drywall on the neighbors side of the shop.

[John K Jordan]

Tyler, I'm no sound expert. I did build an insulated closet for my screaming cyclone and obnoxiously loud air compressor and I can barely hear them in the shop. I used a staggered stud construction - a series of 2x4 studs, staggered to prevent sound transmission directly through the wall. Insulation is snaked between the two. (I used simple fiberglass insulation) One idea if you can afford the wasted space and extra cost is to construct a separate sound-insulated wall inside your structural wall. I assume you will put the dust collector on the end of the shop away from the neighbor.

A lot of sound can escape through the ceiling, vents, windows, and doors too. You might research what recording studios do.

And do you have room to plant some shrubs near the property line?

JKJ

[Doug Ladendorf]

Roxul insulation is made for sound insulation. You might also use a layer of Homosote under the top layer of drywall. It has a sound diffusion aspect. Used on theater stage decking.

Doug

[Lud martinson]

Tyler,
If you have the opportunity To install a new wall inside of your existing exterior wall, adding "sound board" to it prior to final sheeting, that may do the trick. Of course, if your electrical is already in place, that may be prohibitive.

[Craig White]

Spray foam insulation. More expensive but worth it.

Craig

[Shawn Pixley]

Tyler, I'm no sound expert. I did build an insulated closet for my screaming cyclone and obnoxiously loud air compressor and I can barely hear them in the shop. I used a staggered stud construction - a series of 2x4 studs, staggered to prevent sound transmission directly through the wall. Insulation is snaked between the two. (I used simple fiberglass insulation) One idea if you can afford the wasted space and extra cost is to construct a separate sound-insulated wall inside your structural wall. I assume you will put the dust collector on the end of the shop away from the neighbor.

A lot of sound can escape through the ceiling, vents, windows, and doors too. You might research what recording studios do.

And do you have room to plant some shrubs near the property line?

JKJ

I can't say about shops, but in recording studios, they first thing they do is decouple the inner an outer diaphrams as john describes. Adding resilient channels, homosote board, or other item in addition to the insulation will add to the effectiveness.

Windows and doors will be your weak spots. We made a rigid (6") insulation plugs for windows and doors that helped a lot. You could consider building some good shutters for the windows or add a couple panes of glass to keep light coming in.

[Mike Heidrick]

If they are not into power tool noise invest in hand planes no matter the insulation. Even noise blocking is not going to drown the screaming tools. Routers in wood are loud.

[Frank Pratt]

Cellulose & mineral wool are both better than fiberglass, which is better than spray foam. Spray foam is better thermally, but for sound proofing, not so much. Cotton batts are also good, but pricey. Decoupling & mass are also more important than the type of insulation.

[Mel Fulks]

If the cellulose is dense packed ,it will not settle. I used a bunch by breaking it up by hand then putting in plastic bags to make "units". Tedious but effective. Experts use science and precision to get it done fast enough to make a profit. I probably made some technical "mistakes" and used too much material but I got a good quiet job.

[Van Huskey]

Cellulose & mineral wool are both better than fiberglass, which is better than spray foam. Spray foam is better thermally, but for sound proofing, not so much. Cotton batts are also good, but pricey. Decoupling & mass are also more important than the type of insulation.

All true and the last bit is VERY true. For a quicker easier solution than an offset stud wall Green Glue and another layer of drywall is very effective as well.

[Bill Jobe]

I don't think it would help much, but that 14' between you and your neighbor could be a good thick crop of evergreens.

[Robert Engel]

Sounds like it should work. I would consider the possibility you will get some sound coming through the ceiling.

I know of a vet clinic and to control noise from the kennel they built a double 2x4 wall both sides covered in drywall with insulation inside. He said the key is leave a gap between the two walls. They extended this wall all the way up to into the attic to the roof. It works REALLY well.

[Tyler Schroeder]

I can't say about shops, but in recording studios, they first thing they do is decouple the inner an outer diaphrams as john describes. Adding resilient channels, homosote board, or other item in addition to the insulation will add to the effectiveness.

Windows and doors will be your weak spots. We made a rigid (6") insulation plugs for windows and doors that helped a lot. You could consider building some good shutters for the windows or add a couple panes of glass to keep light coming in.

One helpful element is that the wall on the neighbor side has no doors or windows, although there are plenty of holes in the interior wall due to outlets!

[Tyler Schroeder]

Tyler,
If you have the opportunity To install a new wall inside of your existing exterior wall, adding "sound board" to it prior to final sheeting, that may do the trick. Of course, if your electrical is already in place, that may be prohibitive.

I thought about that, but in trying to maximize the square footage of the shop I decided not to. Any idea how sound board performs compared to adding a second layer of drywall?

[Frank Pratt]

You really only need to loose less than 1" for the 2nd wall. Just install new studs between the existing ones & have them project 1/2" or so from the existing studs. That will give you your decoupling & will probably do more than any other single thing to reduce noise transmission. Decoupling is super important. Then throw up a couple of layers of 5/8" drywall with GreenGlue in between. Doing that will only cost you about an inch in floor space.

I thought about that, but in trying to maximize the square footage of the shop I decided not to. Any idea how sound board performs compared to adding a second layer of drywall?