soundproof bathroom

November 6, 2009 5:42 PM

How to best soundproof an existing downstairs 1/2 bath with hollow core door?

The downstairs is one large room with the door to the br in the dining room. The use of that area as dining area not changeable.

Would a solid core door help? Cork on one side of existing door? something to block the 1/4" space @ bottom of door? Exhaust fan not an option. Some sort of white noise machine? Is there one that's battery operated?

Just want to know what would work the best before onslaught of holiday company. I usually send people upstairs for privacy, but that trip is getting hard to manage for some of the elders.

posted by neelhtak to home & garden (10 comments total)

I've done a some research on sound proofing, but I'm not in any way an expert. Most of the sensible advice (non profit driven) I've found has come from AVS forums. There's plenty of questions in their archives to sort through.

The most important thing is to seal off anywhere air can pass, so under the doors if there's a gap.

For your 1/4 inch space I'd initially try a door sweep, it'd be a cheap option to test at least.

Then maybe move onto adding extra mass to the doors/walls (drywall/plasterboard) which will help.

But the if there's still the air gap you will hear noise - imagine a concrete bunker with 10foot deep walls, if the door was open even a crack you'd still be able to hear noise in the adjoining rooms no matter how soundproof the walls were.
posted by selton at 6:13 PM on November 6, 2009

You could actually still rig up an exhaust fan, just make sure it's loosely fitted (under the plastic/metal cover) or has some other way of dumping the air back into the room. Voila, it makes noise and your guests will be more comfortable believing that the fan is removing odors from the room.
posted by 6550 at 6:19 PM on November 6, 2009

A solid door WILL help, yes. I know this from having replaced a hollow-core door on a bathroom (although the bathroom was not right off my dining room). It made a big difference.

A sweep attached to the bottom of the door might help, too.
posted by torticat at 7:12 PM on November 6, 2009

We have ghetto-rigged a wall-mounted fan in the bathroom for privacy. I'm sure with a little more forethought you could set one up nicely, maybe even with a switch by the light switch. It wouldn't vent, but it would circulate air and increase privacy.
posted by radioamy at 7:50 PM on November 6, 2009

Go for the solid door. I just replaced and old hollow door off of the rec-room and find it makes a difference.

About the sweep at the bottom.....it may interfere with any heating that you might have in the bathroom. I mean like a furnace or whatever. The incoming air has to replace the air exiting through the bottom of the doorway. Plus if it is only a 1/4 inch gap, thats not too much too worry about as far as noise goes. You could put a mat (carpet) at the bottom of the doorway and close the door over it if you wanted to find out how much difference sealing off the space would make. Plus you could take it out in the wintertime for the heating issue if there is one.

Maybe put a radio in there for a temporary fix.

But the exhaust fan idea would surely work if you can do that.
posted by Taurid at 8:30 PM on November 6, 2009

We replaced most of the hollow core doors in our house with solid core doors. Not sound proof, but much, much quieter than before.
posted by dws at 10:28 PM on November 6, 2009

Exhaust fan not an option.

Why not, if you don't mind me asking?

A possible solution to your problem is the Toto Otohime, which is designed to provide the covering sound of running water for bathrooms which aren't well soundproofed.

Video of the Otohime in action.

Here's a review in English that says it's battery-powered, in case wiring is an issue.
posted by zippy at 10:56 PM on November 6, 2009

See if you can find a fan with a charcoal filter for smells. They make non-vented fans for kitchens. And a solid door would very likely help a lot.
posted by theora55 at 7:15 AM on November 7, 2009

Thanks for all your input.

Sounds like support for the solid door is solid. :) That's a doer.
Sweep too, since heat not an issue, door can be left open and/or don't mind it being cold in there.

Zippy, I imagine an exhaust fan could be done, but nobody I've asked wants to fool with it. Behind the toilet are the stairs, so it's a sloping wall; directly in front of toilet is sink, mirrored medicine cabinet with light above and sticking into all that the ductwork for the ac; L hand wall is door and elec outlet near sink, light switch R of door, R hand wall is window wall. Outside of house is cedar. Both R and L hand walls have long sloping side to fit under stairs.

Long story short, I'm sure somebody could do it, but there would be wiring issues, and I really wouldn't want them to put a hole in the outside wall. Plus something along the lines of the otohime would do just fine, although I think I'll just go for a beach noises recording. :)
posted by neelhtak at 10:17 AM on November 8, 2009

Bathrooms are terrible for noise because there are so many hard surfaces, any noise just bounces around and sounds really harsh. Try and add more thick, soft surfaces to deaden sounds. Put the biggest, fluffiest towel you can fit onto your towel rail. Put a rug on the floor. Maybe some kind of fabric or woven art on the wall.
posted by Joh at 5:28 PM on November 8, 2009