Plaster vs. drywall for sound dampening

[msmerymac]

First house reconstruction question. 

We had lathe and plaster throughout the house. Where the walls need to be repaired/replaced in the dining room, I want to replaster, because it's somewhat open to the living room and there's also an archway that I think just looks better with plaster. Putting in drywall would necessitate taking out all of the non-damaged walls and re-doing the whole thing, anyway. 

But when it comes to the two upper bedrooms, I'm torn. My husband read that plaster is great for muffling noise. Well... yeah, our walls were slats of wood lathe with plaster over them, so that's a lot thicker than drywall. On the other hand, our walls had virtually no insulation behind them. We can get good insulation now, which will help, and perhaps even the sound proofing type? 

Here's why I'm asking: We live fairly close to a commuter train track, and a crossing, at that, where the train will often whistle. Also, the insurance should pay to get the house exactly as it was, meaning replaster, but if we choose drywall, we can save the money we would otherwise spend on plaster. There are a few tweaks we want to do, now, like remove some wall framing in our bedroom, which just creates dead space, giving us at least 18 inches more floor space and a wall that follows the exterior roof line. And frame a closet into the damaged wall of the guest room. Nothing major, but if we can save a few hundred here and there and have it go towards that, all the better. But would we end up spending so much on good insulation that it would be a moot point?

[msmerymac]

Dec 7, 2013 18:02:47 GMT -5 nursecramer said:

I only have anecdotal data, but our house is way more soundproof than anywhere else I've ever lived. You can blast the stereo in the den and barely hear it in the next room or in the bedroom directly above.

It makes me nervous to hang things in plaster, though. I don't know why. I'm always so paranoid that I'm going to ruin it.

I know! I actually HAVE taken small chunks out of plaster before, though. I'm hoping "new" plaster will be slightly more resilient. Also, my brother is a museum coordinator and his building has plaster walls, so they are always rehanging things and he said you have to drill with a small bit first.

[bunnymendelbaum]

It all depends on how it is built.
Old plaster walls weren't built to any standard and therefore there isn't any way to really say plaster in general is (more) soundproof.

New stud and gypsum board walls should be built to a standard design that comes with an STC (sound transmission coefficient) rating. Things you can go to improve it are add insulation, add another layer if drywall, add a resilient channel between 2 layers of drywall (this is what we are doing to a couple walls at our new house), etc. the idea is to isolate the sound and not let it travel from one material to the next.

How would they be building new plaster walls? That is what I'd ask specifics on.

[pitterwoo]

Busy weekend for me so I didn't get to this till now. I love plaster. Well executed plaster beats well executed drywall. That said, I can agree that there are times to compromise and go with drywall.

First, for the dining room I would strongly encourage you to go with your gut and repair with plaster. I think the difference in feel and texture is noticeable and worth keeping the same as the rest of downstairs.

We actually had almost the same decision to make as you upstairs as all our bedrooms were fire damaged as well. Only in our case new drywall was installed over the wet damaged walls and became a moldy mess for us to discover later. Anyhoo, we did actually go with drywall in the bedrooms. We did because we're really in a watching our pennies place in life and plaster was just another few hundred that we decided to spend elsewhere. Now, honestly I'm not 100% happy that we made that choice. I miss the plaster appearance.

We did use the thickest drywall between bedrooms and additional soundproofing with either drywall or plaster sounds good. I would ask a lot of questions about how they would plan to do the reconstruction. It won't be with lath for sure. It might be plasterboard which is similar to drywall board and then skimmed all over with about a 1/4 inch of smooth plaster coat. If sound deadening is your number one concern, I'm sure it could be achieved using either material.

The one pain about plaster hanging things, but I use Command hooks a lot and for nailing picture hooks Ook hooks are excellent. I wouldn't shy away from plaster for that reason unless you totally rearrange your walls seasonally.

[jloww]

Dec 9, 2013 18:40:57 GMT -5 nursecramer said:

Dec 7, 2013 23:14:21 GMT -5 asdfjkl said:

The drilling is key. Once you do that, though, it's like hanging anything on drywall, you just nail the hook in and hang the picture. We actually just learned that our plaster isn't true plaster. It's some kind of mortar and our lathe is diamond cut steal rather than wood. I guess whoever built this place wanted to make sure it was built to last. But I did snap my smallest drill bit trying to hang a picture before a contractor told me it wasn't traditional plaster. I have to use a masonry bit and a screw to hang stuff. On the flip side, if there's ever a tornado in the area, I feel pretty good about our house making it through.

Even with a pilot hole drilled, I have heard keys falling while pounding the nail in.

What do you mean "keys"?  I can hear stuff falling too and always assumed it was chunks of plaster from the inside or something.  A guy at Home Depot tried to tell me if you heat up the nail with a lighter it will slide through like butter.  He had no idea what he was talking about.  Drill it is.

[jloww]

Dec 10, 2013 14:25:23 GMT -5 nursecramer said:

Dec 10, 2013 13:57:26 GMT -5 jloww said:

What do you mean "keys"?  I can hear stuff falling too and always assumed it was chunks of plaster from the inside or something.  A guy at Home Depot tried to tell me if you heat up the nail with a lighter it will slide through like butter.  He had no idea what he was talking about.  Drill it is.

You're right. The keys are the gobs of plaster that squish in between and behind the lath to anchor the plaster to the wall. If you lose keys, you're more likely to get cracks in your plaster.

Ooooooh!  Good to know!  I'll blame our cracks on missing keys from now on Thanks!

[jloww]

Dec 10, 2013 18:00:30 GMT -5 nursecramer said:

Dec 10, 2013 17:39:36 GMT -5 jloww said:

Ooooooh!  Good to know!  I'll blame our cracks on missing keys from now on Thanks!

Fixing cracks is actually relatively inexpensive, if time consuming. Here's a good tutorial.

Wow!  Is that for hairline cracks too?  We've just been using compound on those when we paint and then they usually crack again anyway so we end up saying F it.

[jloww]

Dec 10, 2013 18:08:16 GMT -5 nursecramer said:

Dec 10, 2013 18:04:22 GMT -5 jloww said:

Wow!  Is that for hairline cracks too?  We've just been using compound on those when we paint and then they usually crack again anyway so we end up saying F it.

Yup. The reason they keep cracking is because they've pulled away from the lath.

Ahh.  I think Ill sit this one out