Insulating the ceiling

SpaceBus

Minister of Fire
Nov 18, 2018
2,920
Downeast Maine
We are neck deep in a renovation right now and the house is nearly gutted. It's more of a camp right now to be honest. We are considering insulating the ceiling on the first floor to make the house more quiet. I feel like this would prevent heat from moving upstairs. The stairwell itself is on the north side of the house and stays 5-10 degrees cooler than the rest of the house. I can't tell if this means there is an active draft of cool air coming down and hot air rising up or if it just stays stagnant and cold. As it stands now our bedroom, bathroom, and second bedroom are upstairs and the kitchen and living areas are downstairs and open concept.

I have attached a hasty layout.
 

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begreen

Mooderator
Staff member
Nov 18, 2005
79,247
South Puget Sound, WA
It will impede heat transfer to some degree. ;) I wouldn't insulate there. What is the concern with quiet? Are there more people than just you and your wife in the house?

Is there an opening between the entry way and the living room? If so, how large?
 

EatenByLimestone

Minister of Fire
Jul 12, 2006
7,097
Schenectady, NY
There is a trend towards more and more interior insulation. Heat will still move through insulation, just slower. The bay doesn't have to be filled completely, a few inches will give a lot of benefit. R12 fiberglass is cheap, why not put a layer in.
 

SpaceBus

Minister of Fire
Nov 18, 2018
2,920
Downeast Maine
It will impede heat transfer to some degree. ;) I wouldn't insulate there. What is the concern with quiet? Are there more people than just you and your wife in the house?

Is there an opening between the entry way and the living room? If so, how large?
I forgot to add a 36" doorway into the main living/kitchen area. My wife doesn't like hearing me walk around upstairs since that's our only bathroom. I had a feeling it would significantly impede heat going to bedroom 1 (the one we use). My wife also thinks that we could use two registers per room in the floor to let heat go up into the bedrooms, but I have my doubts.

an updated layout is attached.
 

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EatenByLimestone

Minister of Fire
Jul 12, 2006
7,097
Schenectady, NY
If your "walking" in the bathroom is the issue, just insulate there. Plenty of heat will still get in there through the doorway. You won't have to walk in the cold, lol.
 

SpaceBus

Minister of Fire
Nov 18, 2018
2,920
Downeast Maine
There is a trend towards more and more interior insulation. Heat will still move through insulation, just slower. The bay doesn't have to be filled completely, a few inches will give a lot of benefit. R12 fiberglass is cheap, why not put a layer in.
That's not a bad idea. We are using Rockwool R23 for the exterior walls, but that would probably be a bit overkill for our ceiling. We are definitely using the rock wool around our plumbing that's right above the kitchen. It's obnoxious hearing each other using the bathroom while sipping coffee ;lol
 
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begreen

Mooderator
Staff member
Nov 18, 2005
79,247
South Puget Sound, WA
We don't wear shoes in the house. No one hears you walking around in house slippers.

Micore is considered one of the best sound insulators. This is what's used in sound deadening panels for office cubicles. If you can find some surplus panels they can be a good scavenge source.

For better heat circulation, try a fan on the floor, in the entryway that blows the cooler air into the living room. A 12" table fan or box fan will work. Run it on low speed. This should help establish a convection loop for better heating upstairs. Cool air being pushed down low into the living room will be replaced with warm air at the top of the doorway. If you tape a piece of toilet paper to the top of the door frame you will be able to see this working.
 
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SpaceBus

Minister of Fire
Nov 18, 2018
2,920
Downeast Maine
We don't wear shoes in the house. No one hears you walking around in house slippers.

Micore is considered one of the best sound insulators. This is what's used in sound deadening panels for office cubicles. If you can find some surplus panels they can be a good scavenge source.

For better heat circulation, try a fan on the floor, in the entryway that blows the cooler air into the living room. A 12" table fan or box fan will work. Run it on low speed. This should help establish a convection loop for better heating upstairs. Cool air being pushed down low into the living room will be replaced with warm air at the top of the doorway. If you tape a piece of toilet paper to the top of the door frame you will be able to see this working.
The old creaky floor is the issue. Neither myself or my wife wear shoes inside, aside from slippers. Currently we have no issues with heat moving through the house. My wife is really sensitive to sound, so we will probably end up insulating the whole first floor ceiling. She wants the house to be silent like a tomb.
 

EatenByLimestone

Minister of Fire
Jul 12, 2006
7,097
Schenectady, NY
Maybe insulation alone isnt the answer alone? Perhaps stiffening the old creaky floor is part of it?


You may want to glue and screw sheathing over the old boards to stiffen it up. Foam, while expensive, will also stiffen a structure.
 

SpaceBus

Minister of Fire
Nov 18, 2018
2,920
Downeast Maine
Maybe insulation alone isnt the answer alone? Perhaps stiffening the old creaky floor is part of it?


You may want to glue and screw sheathing over the old boards to stiffen it up. Foam, while expensive, will also stiffen a structure.
The flooring upstairs is old wide spruce tongue and groove. Unfortunately the floors boards have lived a hard life; they are covered in small round dents, scuffs, deep scratches, cupping, shrinking, and they are generally beat. With so many things going on at one time, we want to just paint it and wait a few years. If it were up to me, I wouldn't do anything and not insulate the ceiling, but it's not up to me. My wife wants our house to be recording studio quiet. This is the main reason we are going with the rockwool insulation for the exterior walls. The way in which the insulation is manufactured leaves a lot to be desired from an emissions standpoint, and it's expensive, but I'm hoping to do this and be done for the rest of my life.
 

EatenByLimestone

Minister of Fire
Jul 12, 2006
7,097
Schenectady, NY
Foam the floors then. I've seen it make old factories have quiet floors. Itll hold every board in 1 place. Figure a dollar per square foot 1" thick. You'll probably want 2-3".


One thing to remember though, is you dont have air movement through the foam. It may take longer for the place to heat up, since all the heat has to go through the stairway. You may want to put an electric baseboard in each bedroom just to give an extra kick of heat if the room doesn't warm up fast enough. Best case is you never have to use it. Worst is hearing your wife tell you shes cold the rest of your life.
 
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SpaceBus

Minister of Fire
Nov 18, 2018
2,920
Downeast Maine
Foam the floors then. I've seen it make old factories have quiet floors. Itll hold every board in 1 place. Figure a dollar per square foot 1" thick. You'll probably want 2-3".


One thing to remember though, is you dont have air movement through the foam. It may take longer for the place to heat up, since all the heat has to go through the stairway. You may want to put an electric baseboard in each bedroom just to give an extra kick of heat if the room doesn't warm up fast enough. Best case is you never have to use it. Worst is hearing your wife tell you shes cold the rest of your life.
Thankfully the house already has the electric baseboard heaters. The boards are fastened to cdx plywood which is fastened to the joists, would that make a difference for the foam?
 

EatenByLimestone

Minister of Fire
Jul 12, 2006
7,097
Schenectady, NY
No. If foamed from below, itll stick to the spruce and CDX.
 

EatenByLimestone

Minister of Fire
Jul 12, 2006
7,097
Schenectady, NY
Look up closed cell foam.
 

Dobish

Minister of Fire
Oct 26, 2015
1,990
Golden CO
we had a room under our living room that was insulated in the ceiling. I took some of it out, and it was noticeably louder in that room. When we redo it, I fully plan on re-insulating that space. 3 of the 4 walls are below grade, so it stays a pretty consistent temperature. There is no insulation on 2 of the 4 walls as well, which we plan on addressing when we redo it.

Fortunately, that is the only room that actually has living space above it, since everything else is either above a crawl space or has no second floor on it.
 

AlbergSteve

Minister of Fire
Dec 11, 2017
607
Vancouver Island
Personally I wouldn't foam the floor. Foam is rigid and will transfer sound. Worked on a house a few years ago where the owner tried to isolate mechanical noise in an attic space from the bedrooms by spraying 1/2 pound foam between the ceiling truss space. Spent thousands doing it and in the end removed all the foam and replaced with Roxul. Commercially and in multi unit construction we use Roxul and resilient bar to acoustically decouple the the drywall diaphragm from the ceiling joists or wall studs. When we reno'd a few years ago every cavity was filled with Roxul and the house is like a tomb.
 
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semipro

Minister of Fire
Jan 12, 2009
3,611
SW Virginia
In general low frequency sound travels through solid materials while higher frequency sounds travel through air gaps.
The former can be addressed with decoupling and sound absorption materials like Roxul as @AlberSteve mentioned; the latter by air sealing.
I've spent almost 20 years now closely watching how heat moves in our 2 story house. Hot air will move up stairways and cold down. In our case, the heat moving upstairs gets trapped in the hallway and not much makes it to the other rooms. That's okay with us because we like colder sleeping areas. The bathroom is another issue though. We've addressed that with duct between 1st and 2nd floors that allows heat to flow to our bathroom on the 2nd floor. You need to put a fire damper in it though to prevent the spread of flame upstairs. The duct also allows sounds to travel both ways so there's that.
 

blades

Minister of Fire
Nov 23, 2008
3,333
WI, Leroy
celulose loose fill blown in insulation does a very good job of deadening sound travel and air migration at the same time- unlike any of the various types of batting additionallyl even after many years and settling it does not lose its r value nor does the R value change with temperature unlike fiber batting.
 
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semipro

Minister of Fire
Jan 12, 2009
3,611
SW Virginia

Seasoned Oak

Minister of Fire
Oct 17, 2008
6,484
Eastern Central PA
celulose loose fill blown in insulation does a very good job of deadening sound travel and air migration at the same time- unlike any of the various types of batting additionallyl even after many years and settling it does not lose its r value nor does the R value change with temperature unlike fiber batting.
Iv found that i does not pack well if blown in from a single hole in the wall. I do at least 2 holes now or install the lower drywall sheet and fill before installing the upper one,when drywalling horizontally.
 

blades

Minister of Fire
Nov 23, 2008
3,333
WI, Leroy
actually the best bet for walls is dense packed cellulose. blown in if a retrofit ( 2 holes yep) takes a different machine as the pressure applied is about double or more than a standard attic job. In new construction walls are done with a wet pack. application kinda looks like foam- but no residual chemical leakage from improper mixing/ temperature at application ( this is becoming a big issue of late)
 

Seasoned Oak

Minister of Fire
Oct 17, 2008
6,484
Eastern Central PA
actually the best bet for walls is dense packed cellulose. blown in if a retrofit ( )
Its very hard top beat the performance vs cost on cellulose. Iv been toying with buying spray foam equipment for a long time, but just cant get past the high cost. Where i want foam i use the sheets.
 

SpaceBus

Minister of Fire
Nov 18, 2018
2,920
Downeast Maine
My wife doesn't like blown in insulation, she worries about what happens when the walls need to be opened up.
 
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