# Basement Sprayfoam Quote



## mass_burner (Feb 11, 2014)

I got a quote for basement insulation and the company recommended 5.5 " open cell spray R20 foam around the entire perimeter of the basement to fill in the joist bays. Does this sound right? They also included
Kraft faced fiberglass batts for the rest of the ceiling, but I'm holding off on this for now. I don't think I want a traditional ceiling in there when I finish it, more of a modern industrial look and the batts would conflict with that I think.

Some info: Basement is unfinished and runs entire footprint of the house, 2000 sq.ft. Its completely below grade, poured foundation with 8 ft ceilings. Basement also is separated from the 2 car garage by two sliding 2" aluminum clad doors, foam inside I'm guessing. Buderus oil fired burner and water tank are in the basement.


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## velvetfoot (Feb 11, 2014)

I'm totally no expert, but would closed cell foam be better there?
Also, what huge, fantastic space, I can't see why you wouldn't want to insulate the walls instead of the ceiling, especially if you have some finishing plans.


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## mass_burner (Feb 11, 2014)

velvetfoot said:


> I'm totally no expert, but would closed cell foam be better there?
> Also, what huge, fantastic space, I can't see why you wouldn't want to insulate the walls instead of the ceiling, especially if you have some finishing plans.


 

Yea, its pretty rare around here. I want the walls/floor to stay concrete, I plan on doing that process that smoothes them down. I'm going  for a real modern look, house is a mid-century modern, built in '55. Besides, all the cold comes in from the rim joists near the ceiling, the walls are insulated with, well...the rest of the earth.


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## blazincajun (Feb 11, 2014)

Been thinking of doing the same thing under our home except we will go with closed cell because of moisture in the crawl space. If we had living space instead I guess open cell would be appropriate.


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## velvetfoot (Feb 11, 2014)

"Cut wood to 10" and load north/south most of the time"

Off topic, but kudos to you!


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## Minnesota Marty (Feb 11, 2014)

mass_burner.  You are on the right track.  Foaming the rim joist. Open cell or closed cell in a rim joist application IMO doesn't matter. The R-20 is excellent.  Closed cell will get you a little more but at probably a higher cost. WIll you recover that cost ?  Without knowing other factors hard to tell. Insulating the rim joist is one of the most important things one can do as a retro-fit on tightening up the envelope. 
Here is where I  beg to differ with you.  Not sure where the frost line is where you are.  Here in Central Minnesota our frost line is 42" down.  Below that the earth is acting as an insulator only to about 40 - 45 degrees.  Above that you need insulation to stop the cold from coming thru the concrete.  Ideally, foam on the exterior to stop the cold from even getting into the concrete is the ticket. But, since you don't want to dig up around your house to foam it so stop the cold with foam on the inside. Trying to achieve at least an R-10 on the walls would be money well spent. 
I have been a Contractor for 30 years and spending money on the envelope above and below grade is direct fuel savings. There are numerous sites to help you learn about tightening up the envelope.  One motto i try to impress on my clients is, "insulate tight and ventilate right".


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## semipro (Feb 11, 2014)

mass_burner said:


> They also included
> Kraft faced fiberglass batts for the rest of the ceiling, but I'm holding off on this for now. I don't think I want a traditional ceiling in there when I finish it, more of a modern industrial look and the batts would conflict with that I think.


Unless the fiberglass batts are in intimate contact with the floors above they won't do much good.  This can be tough to do from below.   You could install EPS or XPS board to the bottom of the floor instead of the batts.


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## mass_burner (Feb 11, 2014)

Minnesota Marty said:


> Below that the earth is acting as an insulator only to about 40 - 45 degrees. Above that you need insulation to stop the cold from coming thru the concrete. Ideally, foam on the exterior to stop the cold from even getting into the concrete is the ticket. But, since you don't want to dig up around your house to foam it so stop the cold with foam on the inside. Trying to achieve at least an R-10 on the walls would be money well spent.


 

I want to do this gradually and see the performance. To start with, the temp has never been below 56d in the basement, even on a -14 night when the furnace has not been running all day. Its pretty much 60-65d on the hottest, most humid day also. I keep a dehumidifer running year round. It also has a large open fireplace which I plan to throw an insert in later.

Bottom line, I don't think I'll get much benefit from wall insulation, the guy who came out to do the quote didn't think so either. Also we're on a hill, maybe that has something to do with it. Our garage/basement is actually level to the ground floor of the folks across the street. I guess you could say the garage/basement is dug into the side of the hill.


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## Circus (Feb 11, 2014)

mass_burner said:


> Kraft faced fiberglass batts for the rest of the ceiling, but I'm holding off on this for now.


 
Why insulate between a 70F basement and 70F first floor?  I agree, the sill needs a good seal and insulation.

What is the smoothing you mentioned? Shiny?


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## mass_burner (Feb 11, 2014)

Circus said:


> Why insulate between a 70F basement and 70F first floor?  I agree, the sill needs a good seal and insulation.
> 
> What is the smoothing you mentioned? Shiny?


 

well its not 70d yet, I'm hoping the sill will get me closer to that. cieling temp was 58 the other day when I checked.


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## woodgeek (Feb 11, 2014)

mass_burner said:


> well its not 70d yet, I'm hoping the sill will get me closer to that. cieling temp was 58 the other day when I checked.



I like the one step at a time approach.  The sill is a great place to start, and will make it warmer (and might cut down on dehumidifer use in the summer), but I would bet it won't make it 'warm'.  I would plan on insulating the walls to the floor (assuming no water issues).  Not hard...1.5 to 2" of rigid foam, furring strips nailed or tapconned into the concrete, and drywall on the furring. No studs required.  Then it'll be warm and feel like a real room.  With a polished floor.

Don't insulate the ceiling.....just something for the next guy to tear out.


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## mass_burner (Feb 11, 2014)

woodgeek said:


> I like the one step at a time approach.  The sill is a great place to start, and will make it warmer (and might cut down on dehumidifer use in the summer), but I would bet it won't make it 'warm'.  I would plan on insulating the walls to the floor (assuming no water issues).  Not hard...1.5 to 2" of rigid foam, furring strips nailed or tapconned into the concrete, and drywall on the furring. No studs required.  Then it'll be warm and feel like a real room.  With a polished floor.
> 
> Don't insulate the ceiling.....just something for the next guy to tear out.


 

thanks woodgeek, but I am definitely not putting up drywall, that's been done to death. i'll install a zero clearance pellet stove at the end of the hallway upstairs to heat the bedrooms before drywall, probably cheaper too.


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## AK13 (Feb 11, 2014)

Is the space above the basement heated? If so then insulating the ceiling is a total waste of time and money. The only reason to insulate would be for sound separation if that mattered to you for some reason. Thermally its a waste of time and money and I'd be leery of any insulation company that suggested doing that. 

I'd go to 5.5" at the rim joists and anywhere above grade. Below grade I'd probably have them just spray 2-3" to get a nice continuous air and moisture seal.


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## maple1 (Feb 12, 2014)

I would absolutely insulate the entire basement walls, from the basement floor right up to the underside of the first floor sheathing. With nothing but either outside air or the earth on the outside of the concrete - well, you couldn't have a more effective heat sink to absorb whatever heat is in the basement. I also agree with others that the only reason to insulate the basement ceiling would be for sound absorption - unless you're trying to keep your basement cold.


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## velvetfoot (Feb 12, 2014)

Apparently, aesthetics is trumping everything else here, which is cool.  "Cool", get it?


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## mass_burner (Feb 12, 2014)

AK13 said:


> Is the space above the basement heated? If so then insulating the ceiling is a total waste of time and money. The only reason to insulate would be for sound separation if that mattered to you for some reason. Thermally its a waste of time and money and I'd be leery of any insulation company that suggested doing that.
> 
> I'd go to 5.5" at the rim joists and anywhere above grade. Below grade I'd probably have them just spray 2-3" to get a nice continuous air and moisture seal.


 

all space above is heated, living area. the insulation guy said you might want to do for sound/vibration reasons.


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## mass_burner (Feb 12, 2014)

velvetfoot said:


> Apparently, aesthetics is trumping everything else here, which is cool.  "Cool", get it?


 

i get it. yes, aesthetics is a major concern. but i keep going back to the baseline: the temp has never been below 56d in the basement, this was recently on a -14 night when the furnace has not been running all day. Its pretty much 60-65d on the hottest, most humid day. The -14 was extreme, in normal winter, 32d, I go down there in a t-shirt for hours at a time. Also, it does have a fireplace in which I will put an insert some day. My biggest concern now is getting the upstairs bedroom floors warmer. I'm hoping the sill work will help increase the temp (58) air on the basement ceiling.


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## dja950 (Feb 12, 2014)

How many sq ft are you looking to get sprayed? I own a sprayfoam business in New York and can tell you if your being overcharged.


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## velvetfoot (Feb 12, 2014)

Anywhere near Albany?


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## dja950 (Feb 12, 2014)

I'm out of Syracuse ny....closed cell does cost more but your also getting twice the r value per inch. The product we're spraying now is r7.4 per inch, and the open cell is only 3.6 per inch. So while per inch the cost is more, cost for similar r value is closer to even if that makes sense.


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## velvetfoot (Feb 12, 2014)

I was thinking there could be some water involvement through cracks at the sill, which I would assume closed cell would be better.


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## woodgeek (Feb 12, 2014)

Yup.  The rooms above are too cold for comfort, due to the room underneath that is not too cold for comfort.  Presumably the rooms above have more cold-sensitive people than the OP, and the OP doesn't mind the cooler temp in the basement 'man-cave'.  Confusing, but makes sense.  The rims will make the room below warmer, and the rooms/floors above a little warmer too, and match the modern aesthetics.  

So, after the sill work, you are hoping that the cold-sensitive folks upstairs will stop griping, and if the basement is still a little cool, that is fine with you.  And you will save energy.

Our insulation plans will def make the upstairs and the basement 'comfy' and save even more energy, but that is not really the goal.  Got it.

I am worried that what if when you are done, the upstairs people are still cold, even though you are NOT cold in the basement?  They will want action.  An insert in the basement will eat a lot of BTUs and send most to the earth.  Getting the upstairs warm might require overheating of the basement, which would be undesirable for the most cold-resistant resident.

Solution, simple: figure out how to get more heat to the first floor after rim sealing.  Bigger first floor stove, fans, rebalanced HVAC, etc.


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## velvetfoot (Feb 12, 2014)

Carpet?


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## mass_burner (Feb 12, 2014)

dja950 said:


> How many sq ft are you looking to get sprayed? I own a sprayfoam business in New York and can tell you if your being overcharged.


 

I'm having the basement done in conjuction with the area/room where the stairs come down to the garage from the kitchen. This area ceiling/walls are getting completely foamed/insulated as it is affected more by the colder garage air and outside walls where the stairs come down. So to do this area, about 8x20 and the sills in the basement the quote is $900.


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## mass_burner (Feb 12, 2014)

woodgeek said:


> So, after the sill work, you are hoping that the cold-sensitive folks upstairs will stop griping, and if the basement is still a little cool, that is fine with you.  And you will save energy.
> 
> I am worried that what if when you are done, the upstairs people are still cold, even though you are NOT cold in the basement?  They will want action.  An insert in the basement will eat a lot of BTUs and send most to the earth.  Getting the upstairs warm might require overheating of the basement, which would be undesirable for the most cold-resistant resident.
> 
> Solution, simple: figure out how to get more heat to the first floor after rim sealing.  Bigger first floor stove, fans, rebalanced HVAC, etc.


 
The bedroom floors may still be too chilly after the sill is done. But I think the reason then would be our original 1955 awning windows or  wall insulation. I'll need evaluate that after the sill is done. Like I said before, in the long run, putting a zero clearance wood/pellet stove at the end of the bedroom hallway might be cheaper than replacing 6 36x18 windows across the 3 bedrooms.


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## mass_burner (Feb 12, 2014)

velvetfoot said:


> Carpet?


 

except for baths, oak harwood is everywhere in the house, even the kitchen. we only use a few area rugs.


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## velvetfoot (Feb 12, 2014)

Our house came with insulation in the basement ceiling, and people have asked if we had floor heat, so it must be pretty warm.  Just saying maybe it could do some good.


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## mass_burner (Feb 12, 2014)

velvetfoot said:


> Our house came with insulation in the basement ceiling, and people have asked if we had floor heat, so it must be pretty warm.  Just saying maybe it could do some good.


 

you might be right...but that's alot trouble and cost to find out. i was thinking of putting up a few sq ft of batts as a test. But the results might not be predictive.


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## mass_burner (Feb 12, 2014)

mass_burner said:


> you might be right...but that's alot trouble and cost to find out. i was thinking of putting up a few sq ft of batts as a test. But the results might not be predictive.


 

also, i'm planning of putting up floating ceiling panels here and there with the ceiling above them visable. visible insulation doesn't fit the design.


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## AK13 (Feb 12, 2014)

Right now the basement is being heated through the 1st floor. If there is no heat down there and its 32 F outside and 55 F in the basement with no heat source down there then that is what is happening. If the 1st floor is cold then you really need the wall/sill insulation plus a little heat in the basement to heat it up to 70 F (or close to the 1st floor setpoint) to keep it from "stealing" heat from the 1st floor.  

Ceiling insulation is dumb unless the basement is a completely cold, unoccupied space with no water piping etc. If that was the case you'd insulate and air seal the ceiling and not the walls. But that clearly isn't the case for your basement. I know its a common approach, but its incorrect. It sounds like your contractor was focused on noise so I think they understand this as well. Either way, I'd definitely skip it. 

I think you are absolutely on the right track. And $900 sounds like a good price for the foam, though I'm not clear on how many sq-ft you are talking about doing.


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## mass_burner (Feb 12, 2014)

AK13 said:


> Right now the basement is being heated through the 1st floor. If there is no heat down there and its 32 F outside and 55 F in the basement with no heat source down there then that is what is happening. If the 1st floor is cold then you really need the wall/sill insulation plus a little heat in the basement to heat it up to 70 F (or close to the 1st floor setpoint) to keep it from "stealing" heat from the 1st floor.
> 
> Ceiling insulation is dumb unless the basement is a completely cold, unoccupied space with no water piping etc. If that was the case you'd insulate and air seal the ceiling and not the walls. But that clearly isn't the case for your basement. I know its a common approach, but its incorrect. It sounds like your contractor was focused on noise so I think they understand this as well. Either way, I'd definitely skip it.
> 
> I think you are absolutely on the right track. And $900 sounds like a good price for the foam, though I'm not clear on how many sq-ft you are talking about doing.


 
1. i always assumed the 60d was coming from the earth around the basement walls. In summer, its still 65, although the temp upstairs is 95. We don't have AC.

2. the basement. where the sill work is needed is roughly 30' x 25', maybe bigger. i'll take a measurement tonight.


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## Minnesota Marty (Feb 12, 2014)

AK13 - Keep going your getting to them.  
Let me try it this way. I would assume in your location SE Mass there is frost in the ground. Not sure how far down the frost goes down. That doesn't matter. Go check and see how far out from the foundation where the ground is not frozen. 3", 4" or whatever.  That is heat escaping from your foundations that wall insulation will not allow to happen as much. Since you can't insulate the foundation from the outside you cannot eliminate that heat escape completely but, you can help with wall insulation. 
mass_burner: do you have a garage that is referred to as a tuck under the house garage, which is adjacent to the basement? 
The insulation guy well intentioned but between floors insulation is ONLY for sound control. If that what you want then yes.


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## mass_burner (Feb 12, 2014)

> Go check and see how far out from the foundation where the ground is not frozen. 3", 4" or whatever[/QUOTE. ]
> 
> ---i'll do that
> 
> ...


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## Minnesota Marty (Feb 12, 2014)

I would insulate that garage from the house so fast it would make your head spin. Opening and closing garage doors is a heat loss culprit. I would make sure the ceiling in the garage is insulated really well and then a firestop of 5/8" sheetrock that is taped. (firetaped)  Assuming there is living space above the garage. Then the common wall from the garage to the rest of the basement I would also insulate as best I could and again 5/8" rock both sides. If your pulling a building permit the inspector is going to catch that.  UBC firecode - mandatory. 
Your contractor should know this.


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## mass_burner (Feb 12, 2014)

> Right now the basement is being heated through the 1st floor.


 
If this is happening, then there should be a difference in ceiling temp from the back bedroom, where there is no heat on during the day, and the family room where the inserts are. back bedroom is 64d; family room 73d. So if I went to these spots in the basement ceiling they would show a 10d difference?


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## mass_burner (Feb 12, 2014)

Minnesota Marty said:


> I would insulate that garage from the house so fast it would make your head spin. Opening and closing garage doors is a heat loss culprit. I would make sure the ceiling in the garage is insulated really well and then a firestop of 5/8" sheetrock that is taped. (firetaped)  Assuming there is living space above the garage. Then the common wall from the garage to the rest of the basement I would also insulate as best I could and again 5/8" rock both sides. If your pulling a building permit the inspector is going to catch that.  UBC firecode - mandatory.
> Your contractor should know this.


 

Garage ceiling is plastered, within a year of moving in, I had cellulose blown in through cut-out holes. The dining room is above the garage. it was a big improvement. The basement is separated from the 2 car garage by two sliding 2" aluminum clad doors, foam inside I'm guessing. Between the 2 doors is the basement to roof chimney and cinder block on each side of the chimney framing the 2" aluminum doors. 

So from left-to-right its:

cinder block wall-aluminum door-cinder block wall-chimney-cinder block wall-aluminum door-cinder block wall


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## moey (Feb 12, 2014)

Id be concerned about any company that would put kraft faced fiberglass bats in your joists. Lets see it falls down a little air gets in and its worthless. Might stop some sound.


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## velvetfoot (Feb 12, 2014)

Plus, with my fg batts, it always rains down fibers anytime you go near.  I'm thinking of covering it up with black landscaping cloth stapled to the underside of the joists.  It would contain the fiberglass, black out the ceiling, and be easily removable.


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## moey (Feb 12, 2014)

Why not use Roxul in the joists it will stay tight doesn't burn and will actually insulate. In my opinion adding fiberglass is a big no no except maybe in your attic.


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## mass_burner (Feb 12, 2014)

velvetfoot said:


> Plus, with my fg batts, it always rains down fibers anytime you go near.  I'm thinking of covering it up with black landscaping cloth stapled to the underside of the joists.  It would contain the fiberglass, black out the ceiling, and be easily removable.


 
that's a great idea. you could even paint it.


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## velvetfoot (Feb 12, 2014)

It probably wouldn't breath as well then.  I think where basements are concerned, breathing is good.


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## Where2 (Feb 12, 2014)

mass_burner said:


> The bedroom floors may still be too chilly after the sill is done. But I think the reason then would be our original 1955 awning windows...



If they are as leaky as my 1962 awning windows were, I'd start packing my lunch for as long as it takes to replace all those awning windows the day after you get the rim joist insulated. Before I replaced my 1962 awning windows, when my A/C was running, I used to be able to literally feel the A/C bleeding out of them if I held my hand near the middle seam on any of the windows in the middle of summer. In winter, when the wind blew, I could feel drafts inside from the leaks in those awning windows. For the 12 years I owned my house before I replaced the awning windows, I might as well have opened them and been tossing dimes an quarters out of them for all they cost me.


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## mass_burner (Feb 12, 2014)

Where2 said:


> If they are as leaky as my 1962 awning windows were, I'd start packing my lunch for as long as it takes to replace all those awning windows the day after you get the rim joist insulated. Before I replaced my 1962 awning windows, when my A/C was running, I used to be able to literally feel the A/C bleeding out of them if I held my hand near the middle seam on any of the windows in the middle of summer. In winter, when the wind blew, I could feel drafts inside from the leaks in those awning windows. For the 12 years I owned my house before I replaced the awning windows, I might as well have opened them and been tossing dimes an quarters out of them for all they cost me.





Where2 said:


> If they are as leaky as my 1962 awning windows were, I'd start packing my lunch for as long as it takes to replace all those awning windows the day after you get the rim joist insulated. Before I replaced my 1962 awning windows, when my A/C was running, I used to be able to literally feel the A/C bleeding out of them if I held my hand near the middle seam on any of the windows in the middle of summer. In winter, when the wind blew, I could feel drafts inside from the leaks in those awning windows. For the 12 years I owned my house before I replaced the awning windows, I might as well have opened them and been tossing dimes an quarters out of them for all they cost me.


they're not that bad. these windows allow an extra pane on the outside and on the inside. so we actually have triple pane.


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## ksc (Feb 13, 2014)

You might want to contact MassSave. They will do a complete energy audit for free. We had one done yesterday, the guy was here for over 4 hours testing the house. They give you up to $2000 towards the work they recomend and threw in about $900 worth of air sealing for free. Replaced all our lightbulbs, gave us a few fancy powerstrips, and even gave me a nice programable thermostat which we decided not to instal given our 52* thermastat setting. Our house has basically no insulation so to insulate the attic with 12" cellulse, all exterior walls with 4" and do the air sealing came out to about $6000. It will cost us about $3000 which can be financed @ 0% interest for 7 years.


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## Minnesota Marty (Feb 13, 2014)

ksc, great advice.


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## woodgeek (Feb 13, 2014)

indeed.  everyone in MA is already paying into MassSave on their elec bils, might as well get something back.


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## mass_burner (Feb 13, 2014)

already did mass save. had the attic sealed and cellulose blown in , doors to attic made and sill plate air sealed. doors also weather stripped. problem is MS does not do spray foaming. except in small amounts. MS guy said they might add it this spring, but I'm not holding my breath.


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## velvetfoot (Feb 13, 2014)

I put multiple layers of xps foam board in my sill plate, but it was tedious, mostly because I went for a tight fit because of the multiple layers and the fact that I don't like to work with great stuff.  I figured out the cost of the xps at one point and even the material cost was high and more than what I figured, after the fact, that spray foam would be.


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## DickRussell (Feb 14, 2014)

For foaming the sill area, you want closed cell foam, not open cell. OC is too water vapor permeable. You want interior wintertime humidity kept away from what will be a cold rim board.

I'd echo the opinions of others on insulating the walls: do it (after the floor polishing work, of course). Your basement is staying in the mid 50s all winter because the deep ground is in the low 50s, and progressively colder as you get toward the surface. Those concrete walls are sucking a lot of heat out of the house, and a good part of that heat is from the floor above, contributing to their feeling cold. Even if you don't add heat to the basement after insulating the rim and walls down there, the temperature will rise to perhaps the mid-60s, and that in turn will improve the temperature of the floor above.

A lot of good information on basement insulation can be found here:
http://www.buildingscience.com/search?SearchableText=basement+insulation
http://www.greenbuildingadvisor.com/blogs/dept/musings/how-insulate-basement-wall
http://www.greenbuildingadvisor.com/blogs/dept/guest-blogs/basement-insulation-part-1
http://www.greenbuildingadvisor.com/blogs/dept/guest-blogs/basement-insulation-part-2

How and why to insulate a basement has been discussed all over the place. You ought to do some reading before you decide on what to do.


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## mass_burner (Feb 14, 2014)

DickRussell said:


> For foaming the sill area, you want closed cell foam, not open cell. OC is too water vapor permeable. You want interior wintertime humidity kept away from what will be a cold rim board.
> 
> I'd echo the opinions of others on insulating the walls: do it (after the floor polishing work, of course). Your basement is staying in the mid 50s all winter because the deep ground is in the low 50s, and progressively colder as you get toward the surface. Those concrete walls are sucking a lot of heat out of the house, and a good part of that heat is from the floor above, contributing to their feeling cold. Even if you don't add heat to the basement after insulating the rim and walls down there, the temperature will rise to perhaps the mid-60s, and that in turn will improve the temperature of the floor above.
> 
> ...


 

Thanks, I will do more research. What sounds counter-intuitive are these statements in this thread.

1. heat is being stolen from the first floor into the basement via the basement ceiling.
2. but insulating the basement ceiling will not do any good.

Why wouldn't  basement ceiling insulation stop the transfer of warm air from the first floor to the basement? Isn't this the same concept applicable in the first floor cieling to attic?


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## woodgeek (Feb 14, 2014)

Insulating the basement ceiling will def make the upstairs warmer, and render the basement much colder, increase your dehumidifier needs, and otherwise make it a permanently suckier place to be (until the next owner pulls the insulation out).  Versus wall insulation and voila, a huge new finished space that is actually comfortable and pleasant and boosts resale.


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## DickRussell (Feb 14, 2014)

Ditto what woodgeek just said. Heat always moves from warm toward cold.  If there is heat movement, there is a temperature difference. If your basement is mid 50s and the ground outside the foundation walls is low 50s and progressively cooler up toward the sill, then it's losing heat. That heat is made up partly by any leakage from the heating system and hot water heater and partly by loss of heat from the floor above. The heat lost by the floor to the basement must be made up by heat from the air in the room above that floor surface, so it must be cooler than the room air temperature. Either insulating under that floor or making the basement warmer (by retarding the loss of heat from the basement through the walls via insulation) will bring the floor temperature closer to that of the air in the room.

Aside from saving on heating cost and improving thermal comfort, both in the basement and in the room above, another reason for insulating the walls has to do with moisture. Despite whatever "dampproofing" may have been applied to the outside of the foundation wall prior to backfilling, that concrete mass always has moisture in it, assuming that the dampproofing was not heavier actual waterproofing and that there was no capillary break placed over the footing before the walls were poured. That moisture always migrates inward to the basement air space. It evaporates quickly, helped by your dehumidification. Without that dehumidification, there could well be that mustiness common to many basements, especially in summer. If the foundation walls are close to ground temperature (you said that the basement stays mid 50s), and summertime humid air masses regularly get to dewpoints mid 60s and higher, you have the tendency of the moisture in that air to condense/be absorbed by the wall surface, fighting your active dehumidification. Insulating the walls with closed cell foam (spray or rigid board) not only warms up the surface that the air sees (thwarting condensation) but also retards migration of water vapor from the concrete into the room. This lessens the load on the dehumidifier and practically eliminates any tendency to develop musty smells, generally enhancing air quality and usefulness of the basement space.

Insulating the basement walls doesn't have to be a terribly expensive project, if you're at all handy with minimal construction projects and thus can DIY it. Done yourself, you can piecemeal it over time, using rigid foam board; I'd recommend 2" board. You will have to provide thermal protection for either type of foam, unless it's foil-faced polyiso (kept 1/2" off the floor). Studs on the flat over the foam and screwed through to the concrete provide space for wiring and shallow electrical boxes before sheetrocking, another DIY effort.


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## mass_burner (Feb 14, 2014)

so should a ceiling ever be spray foamed if the space under it is not living space, just a pass through area?


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## moey (Feb 14, 2014)

mass_burner said:


> so should a ceiling ever be spray foamed if the space under it is not living space, just a pass through area?



The only time I would spray foam a basement ceiling was if it was dirt floor or something nasty where you never go down for any reason.


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## velvetfoot (Feb 15, 2014)

On a side note, would it be worth the hassle for me to remove the insulation in my basement ceiling?  The basement walls have 4" of xps foam on them.


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## mass_burner (Feb 17, 2014)

moey said:


> The only time I would spray foam a basement ceiling was if it was dirt floor or something nasty where you never go down for any reason.


 
Okay, this worries me cause the quote I got also include the area where the stairs come down to the garage from the kitchen. Quote calls for the ceiling to get completely foamed and interior walls insulated. This area is affected more by the colder garage air and outside walls where the stairs come down. This area is about 8x20. I am attaching some pic as a visual.


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## begreen (Feb 17, 2014)

The earth is a giant heatsink. It will suck btus to get from 55 to 70 forever. Insulate the basement walls, then drywall for a smoothwall surface. Then get rid of the basement ceiling insulation if the desire is to heat from the basement.


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## mass_burner (Feb 17, 2014)

begreen said:


> The earth is a giant heatsink. It will suck btus to get from 55 to 70 forever. Insulate the basement walls, then drywall for a smoothwall surface. Then get rid of the basement ceiling insulation if the desire is to heat from the basement.


 

This area in the pics is not living space, its only a walk-through area. It will never be heated from below. Its closed off from the larger area of the basement by two 2" insulated doors. The issue is that this walk-through area is directly under the kitchen in the part of the common area furthest from the inserts. The heat eventually gets there, but as you can imagine the sink/counter/stove area is the area first used in the mornings.


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## moey (Feb 17, 2014)

You may ask them the advantages of doing the ceiling if your doing the walls. The company may have simply saw you had insulation on the ceiling and gave you a quote for replacing it. You may be reading into it to much. 

Your basement looks fairly deep for the coin you would spend insulating the ceiling you could do the floor and completely encapsulate the environment and never have problems with moisture low temps etc.


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## Circus (Feb 18, 2014)

Warning: Smoldering foam insulation produces highly toxic fumes, it must be sealed with something non flamable. My first cousin and her family died after a furnace blower kicked in and spread the fumes throughout the house.  A cigarette started the foam insulation smoldering behind paneling of a basement wall. House was undamaged.
When I sealed my sill, I used fiberglass, drywall and caulk.


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## mass_burner (Feb 18, 2014)

I read somewhere that the rule if thumb for spray foam on ceiling was if the space below it was conditioned or not. well the space below my kitchen is not and is also sealed from any space that is conditioned, as in the rest of the basement. I think spray foam is a good solution. especially since the stairs are resting hard against the wall. that would be a challenge to insulate with foam board.


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## AK13 (Feb 18, 2014)

mass_burner said:


> I read somewhere that the rule if thumb for spray foam on ceiling was if the space below it was conditioned or not. well the space below my kitchen is not and is also sealed from any space that is conditioned, as in the rest of the basement. I think spray foam is a good solution. especially since the stairs are resting hard against the wall. that would be a challenge to insulate with foam board.



Here is my rule of thumb for insulation. If the basement or crawlspace is completely unconditioned space then it would find to make the ceiling your insulation plane and insulate AND air seal it. But that means absolutely no heat in the basement at all. No pipes. Not heating equipment, nada. If its truly a COLD space then absolutely insulate it out of the house and you have that much less space to heat.

My friend has a ranch with a 3' tall crawlspace and poured floor. Fiberglass in the ceiling (all falling down). This might be fine except that his boiler and heating piping are down there. So that is a heated space! And where do you think the heat goes (hint: not up into the house except where the insulation is falling down). It goes out the sill and foundation walls. Since this is heated space we want to remove the insulation at the floor/ceiling and insulate the sills and the foundation walls. That is the correct way to do the job.


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## Retired Guy (Feb 20, 2014)

I understand your idea to insulate the rim joist however, for those of us living in termite country the rim joist is where the critters are easiest found.

Regarding  insulating the concrete walls, I remember a Materials Science Prof's little poem when we were discussing the insulating factor of stone and concrete. 

_"when I walked through marble halls, I froze both my ba###"_


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## mass_burner (Feb 20, 2014)

mass_burner said:


> 1. i always assumed the 60d was coming from the earth around the basement walls. In summer, its still 65, although the temp upstairs is 95. We don't have AC.
> 
> 2. the basement. where the sill work is needed is roughly 30' x 25', maybe bigger. i'll take a measurement tonight.


 

inner basement area is 40 x 25, open area no inner walls, 3 outer walls. that does NOT include the garage or area at the bottom of the stairs that I want spray foamed.


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## billb3 (Feb 21, 2014)

I've seen stairwells to basement insulated just so the walls in the living space on the other side don't feel cold.

I've warmed up ( and helped dry ) basements here in NE in gravel just by making successful efforts at removing as much water/moisture from the soil around the basement walls. Making sure roof water drains away as far away as possible via pipes/dry wells, slope for surface water to run off .


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## mass_burner (Feb 21, 2014)

billb3 said:


> I've seen stairwells to basement insulated just so the walls in the living space on the other side don't feel cold.
> 
> I've warmed up ( and helped dry ) basements here in NE in gravel just by making successful efforts at removing as much water/moisture from the soil around the basement walls. Making sure roof water drains away as far away as possible via pipes/dry wells, slope for surface water to run off .


 

at present I have no water issues, but i'm working my way around the house to keep it that way.

side 1 - a slab patio with deck attached, filled remaing part with gravel, dug new 8' descending water run into yard under ground.
side 2 - garage and driveway slopes away from house, no issue.
side 3 - gutter spouts buried to 8' from foundation into yard. will be installing gravel this spring against foundation
side 4 - will be installing gravel this spring against foundation.

house is on a hill and 3 sides slope down away from house. only rear of house is level with remaining land.


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## Swedishchef (Feb 23, 2014)

I sprayfoamed the my basement walls and rim joists with closed cell, R10. Then added R14 roxul. It gives me R24 and with the roxul was a bit cheaper than R20 sprayfoam.

Spray foaming the rim joists is incredible...NO cold at all coming in.

Now I have a gyprock ceiling and I didn't put insulation in. My basement is now used 50% of the time and that is where my woodstove is located.

Andrew


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## richg (Feb 26, 2014)

I came darn close to starting a spray foam business in the summer of 2008. A minor disturbance in global financial markets ensued and the business was shelved. If given a choice between open cell and closed, go with closed cell and don't look back. It's not just a higher R value from closed cell, rather, it is impermeable by moisture. Shooting open cell on block walls is an invitation for moisture infiltration, and if you have 2x4 studs up against the cinder block and then sheetrock over it, that could be trouble. Bayseal is a good brand of closed cell and should be available for about $1.00 per board foot installed. You will need 50% less depth on a closed cell application due to its higher R value. 3 inches on a wall would be plenty.


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## DBNH22 (Mar 20, 2014)

I had the rim joists in my unfinished, unheated basement sprayed last December.  I had 3" of the closed cell foam sprayed in for R20.  The R value of the closed cell is slightly higher.  I think I may have read something about the open cell being more moisture permeable a while ago too.  You'll have to look into both types yourself to see which is best for you.

Prior to having the rim joists sprayed there were fiberglass batts (R19) on the basement ceiling that were falling down and had suffered wind damage due to unsealed rim joists.  I removed most of them.  The floor above, which is heated space, felt like you were walking on an ice rink on the cold and windy days.  After having the rim joists sprayed it now feels slightly cool on the cold and windy days but it's a significant improvement.

My basement is also a sunken poured concrete foundation.  iIconsidered having the spray foam brought down from the rim joists to the frost line on the walls but did not want to spend the extra money at the time.  I paid $850 and it's a 2400 sq foot colonial, typical footprint.  I may have it done at a later point in time.

I also went around and sealed up the basement sealing holes/airways with Great Stuff in Decmeber, trying to isolate the airflow to/from the living space.  Now I may be experiencing an issue with draft and combustion pertaining to my pellet boiler due to sealing up the basement which is where the boiler lives.  I'm in the process of experimenting with outside air at the moment.  Just another possible thing to think about though.


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## DBNH22 (Mar 20, 2014)

mass_burner said:


> so should a ceiling ever be spray foamed if the space under it is not living space, just a pass through area?




This is an interesting question not only from the heating/insulation perspective but also when thinking about safety/fire hazard.

It's my understanding that the spray foam is very flammable and an the intumecscent coating must be applied to the finished product to allow a 15 minute fire barrier. I had this applied and was also told that there was something in the foam to make it inflammable.  However right above the basement ceiling in most homes is the most active living space, kitchen, living room etc. etc  There are also many electrical wires running along the basement ceiling in may homes.   It's kind of a scary thought to think that there could possibly be a fire started on the basement ceilign which could turn into a raging inferno in a matter of moments due to highly combustible spray foam.  Is my thinking wrong on this?  What is eveyone else's take on it?


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## billb3 (Mar 20, 2014)

Dana B said:


> This is an interesting question not only from the heating/insulation perspective but also when thinking about safety/fire hazard.
> 
> It's my understanding that the spray foam is very flammable and an the intumecscent coating must be applied to the finished product to allow a 15 minute fire barrier. I had this applied and was also told that there was something in the foam to make it inflammable.  However right above the basement ceiling in most homes is the most active living space, kitchen, living room etc. etc  There are also many electrical wires running along the basement ceiling in may homes.   It's kind of a scary thought to think that there could possibly be a fire started on the basement ceilign which could turn into a raging inferno in a matter of moments due to highly combustible spray foam.  Is my thinking wrong on this?  What is eveyone else's take on it?


I don;t know which is worse, the flammability or the thick acrid black choking and gagging smoke . The smoke it makes ( with/without a flame ) is supposed to be  really bad.


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## Swedishchef (Mar 22, 2014)

When spray foam burns it gives off lots of free radicals and the black smoke will kill you in 15-30 seconds (if thick...).

Yes, it does need to be fireproofed. Normally the installer can spray a fire barrier on top. However, i was informed from my National Building Code that placing Roxul on top is perfectly acceptable.

Just remember that technically the foam boards are the same.

Andrew


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## mass_burner (Jun 11, 2014)

okay, still pondering the open cell vs closed cell for my basement rim joists and untreated space below my kitchen (8x20 ceiling spray foam). Insulation guy thinks open cell would work and closed cell would be wasted additional cost. But I'm concerned that OC is not a vapor barrier.


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## begreen (Jun 11, 2014)

I know little on the topic but closed cell is reported to be the best vapor barrier. Best to consult the experts.
http://www.icynene.com/architects/s...-open-cell-closed-cell-spray-foam-insulations
Advise seems to be to use closed cell for below grade (or rigid)
http://www.greenbuildingadvisor.com/blogs/dept/musings/how-insulate-basement-wall

Here it sounds more like they are talking about above grade walls.
http://www.greenbuildingadvisor.com...ng-blog/open-cell-foam-beats-closed-cell-foam


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## mass_burner (Jun 11, 2014)

another detail, both areas, rim joists and untreated space below my kitchen, are above grade.


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## woodgeek (Jun 11, 2014)

Probably depends on other details like capillary break to foundation (or none) and dryability to outside (depends on exterior finish, and can change with the next homeowner).

Why take a chance....rotted sills and rims = game over for a house.


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## DBNH22 (Jun 25, 2014)

velvetfoot said:


> I'm totally no expert, but would closed cell foam be better there?
> Also, what huge, fantastic space, I can't see why you wouldn't want to insulate the walls instead of the ceiling, especially if you have some finishing plans.




I had my basement rim joists foamed last fall.  If I remember correctly the closed cell is more expensive but has more r value per inch and better sealing properties.


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## Enzo's Dad (Jun 25, 2014)

When i get home tonight i will try to get you pictures of my basement remodel. Spray foamed the exterior walls and the cavity betweer the exterior and the celing joist.
The rest of the celing has Roxul doubled up, I actually think your supposed to use roxul for fire code, but i did it for sound my master bed room is on the first floor.

Here is something about spray foam quotes you should look into, do they haul off the excess material. I waqs shocked to come home to 45 garbage bags of sawed off foam. Guess I didnt read the contract. I love it , the basement is quiet and warm. I paid $2000 for about 1000 sqr ft area.

ps i used to have mice in the basement, i have heard they hate the smell of the spray foam.


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## DBNH22 (Jun 25, 2014)

When I had my rim joists done they took all the trash with them when the job was done.  To me it seems unprofessional that they didn't take that with them or at least mention it to you before the job.

As for mice.  I vaccumed all of the dust/mice poop from the basement before I had my rim joists foamed.  That was last December.  Since then I have not noticed any droppings or found any carcasses.

By the way $2000 sounds about right.  I only had the rim joists done in a typical 2400 sq. foot New England colonial and it cost $840.


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