AVS Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter #1
I'm gearing up to start finishing my basement. I'm not doing a full THX theater or anything but I like to listen to music late at night so I'm going to sound proof it as best I can so I don't get yelled at by the wife. I'm quickly figuring out that ALL details need to be worked out before hand WRT the sound proofing. Looks like I'll be able to do all walls as isolated structures, where 3 of the 4 sides are against exterior walls and only 1 wall will be common to the rest of the basement which will be a double studded wall + 5/8" OSB + GG + 5/8" DW. The ceiling will need to be a mixture of independent beams and clips to work around duct work and various obstacles and then the same OSB-GG-DW treatment.

I'm curious about what to do about the floor. I've read a lot from "The Soundproofing Company" website and there are floor solutions there but all of them seem to target upper floors and not a concrete basement. I was thinking on laying the dimpled plastic roll stuff and laying 2x 1/2" OSB or ply on top of that, oriented 90° so I could screw it all together to create one big floating subfloor and then build the interior walls on top of that. I wasn't planning on to tap-con it down to keep the coupling to a minimum. Does this sound like a good plan or is there something else I should consider?

Thanks,
Ryan
 

·
Registered
Joined
·
5,362 Posts
Any idea on how the serentiy mat will hold up under, you know, "wet" conditions?

I'm wondering what the cost would be to do the dimpled plastic, 1 layer OSB, serenity mat, second layer OSB. Or does the seremity mat require the hard surface of the concrete to be effective?

Just throwing options out there.
 

·
RETIRED theater builder
Joined
·
34,690 Posts
floating subfloor and then build the interior walls on top of that.
You will curse that decision in the event that you suffer a water event. Leaky hot water heater for example. If the floor has to come out, what are you going to do?
 

·
Registered
Joined
·
28 Posts
Discussion Starter #7
You will curse that decision in the event that you suffer a water event. Leaky hot water heater for example. If the floor has to come out, what are you going to do?
I've been thinking about this and not sure what an alternative would be. If not anchored on the sub floor, the only other option I can see is anchoring on the slab which seems like a worse solution to me. TBH I thought putting the perimeter walls on the subfloor was a good way to avoid any dampness. If the basement floods to make up the ~1" height of the dimpled plastic or serenity mat then the bottom of the walls will also be water damaged and need to be cut out as well. Maybe there is an obvious solution that I'm missing. However, the water heater is in another part of the basement and is 12" away from the floor drain plus I live near the top of a hill. I can't imagine what would have to go wrong all at the same time during a catastrophic event that would cause >1" of water at this end of the basement.
 

·
RETIRED theater builder
Joined
·
34,690 Posts
I've been thinking about this and not sure what an alternative would be. If not anchored on the sub floor, the only other option I can see is anchoring on the slab which seems like a worse solution to me. TBH I thought putting the perimeter walls on the subfloor was a good way to avoid any dampness. If the basement floods to make up the ~1" height of the dimpled plastic or serenity mat then the bottom of the walls will also be water damaged and need to be cut out as well. Maybe there is an obvious solution that I'm missing. However, the water heater is in another part of the basement and is 12" away from the floor drain plus I live near the top of a hill. I can't imagine what would have to go wrong all at the same time during a catastrophic event that would cause >1" of water at this end of the basement.
the water heater is just one example of what can go wrong. Burst pipe, leaking valve, blockage in the condensation drain of the HVAC, failed sump pump, frozen hose bib, are other examples of what can happen even to a house on top of a hill.

as for alternatives, you anchor the wall framing on the concrete and use PT wood, put down the sub floor leaving a gap equal to the planned thickness of the drywall or even a little shy then you drywall and any remaining gap gets hidden with the 1/2 inch baseboard. if you install your drywall no lower than the top of your subfloor there is a good change a water soaked floor will not ruin the drywall. Some guys put the sub floor in after the drywall leaving 1/2 inch gap.

Houses with water damaged drywall are usually repaired by cutting a strip of drywall at the bottom of the wall letting everything dry and replacing the drywall. The framing stays in place, so if you need to get up the subfloor and it is under the framing you make a cut and a strip of the water soaked sub floor material stays under the framing where it will start to rot/mold.
 

·
Registered
Joined
·
2,663 Posts
and then there is the possibility that a the remains of a Russian satellite will crush your bedroom, sleep with one eye open.
I've been doing that ever since Loreena Bobbitt put ideas in the heads of wives around the world.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #12 (Edited)
as for alternatives, you anchor the wall framing on the concrete and use PT wood, put down the sub floor leaving a gap equal to the planned thickness of the drywall or even a little shy then you drywall and any remaining gap gets hidden with the 1/2 inch baseboard. if you install your drywall no lower than the top of your subfloor there is a good change a water soaked floor will not ruin the drywall. Some guys put the sub floor in after the drywall leaving 1/2 inch gap.
I'd thought about that, but then doesn't anchoring the stud wall to the slab couple them and easily transmit sound or is the mass of the slab enough to kill any energy that get in? Sorry if I'm sounding argumentative, I don't mean to, I'm just trying to get all this sorted out in my head. Also since I didn't see concrete floors mentioned on the soundproofing company site, is the serenity mat OK to lay on the bare concrete?

[edit]I stumbled across a thread here that answered most of my questions but I would like to confirm about anchoring the stud wall to the slab and not having any sound conducting into the the rest of the house. Thanks for your help![/edit]
 

·
RETIRED theater builder
Joined
·
34,690 Posts
yes serenity mat on concrete, you may need DA5 adhesive with a 3/16 V notch trowel.

IMHO the amount of transfer via the concrete is minimal assuming your wall structure is damped mass. Even better if you hang the walls on clips and channel isolation. You could always put strips of the rubber mat under the framing and keep your anchor points to a minimum, if you are buying Serenity mat just buy a little extra.
 

·
Registered
Joined
·
111 Posts
When I did my floor I used serenity mat and 3/4" T&G plywood. I left a 1/2" gap to the floor with the drwyall on the walls. A 1/4" gap was left between the serenity mat/plywood and the walls, which was caulked afterwards. An adhesive was used to secure the serenity mat. The plywood is free floating on top of the serenity mat.

The theory behind this is that by decoupling the floor from the concrete, you can limit the amount of bass that gets into the concrete floor, which can then travel into the foundation walls and flank up into the rest of the house. I have a sand stage that sits on top of the floated plywood floor. There is a 1/4" gap between the stage and the walls, which is caulked also. What I find is that I can have a movie playing at high volume, and in the living room directly above only a very slight rumbling can be heard. I am beyond impressed by how much sound my room contains.
 

·
Registered
Joined
·
1,403 Posts
When I did my floor I used serenity mat and 3/4" T&G plywood. I left a 1/2" gap to the floor with the drwyall on the walls. A 1/4" gap was left between the serenity mat/plywood and the walls, which was caulked afterwards. An adhesive was used to secure the serenity mat. The plywood is free floating on top of the serenity mat.

The theory behind this is that by decoupling the floor from the concrete, you can limit the amount of bass that gets into the concrete floor, which can then travel into the foundation walls and flank up into the rest of the house. I have a sand stage that sits on top of the floated plywood floor. There is a 1/4" gap between the stage and the walls, which is caulked also. What I find is that I can have a movie playing at high volume, and in the living room directly above only a very slight rumbling can be heard. I am beyond impressed by how much sound my room contains.
Is any moisture barrier needed between concrete and serenity mat?
 
1 - 16 of 16 Posts
Top