Basement Sprayfoam Quote

[mass_burner]

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.

 

[velvetfoot]

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.

 

[mass_burner]

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.

 

[blazincajun]

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.

 

[velvetfoot]

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

Off topic, but kudos to you!

 

[Minnesota Marty]

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".

 

[semipro]

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.

 

[mass_burner]

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.

 

[Circus]

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?

 

[mass_burner]

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.

 

[woodgeek]

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.

 

[mass_burner]

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.

 

[AK13]

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.

 

[maple1]

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.

 

[velvetfoot]

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

 

[mass_burner]

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.

 

[mass_burner]

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.

 

[dja950]

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.

 

[velvetfoot]

Anywhere near Albany?

 

[dja950]

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.

 

[velvetfoot]

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

 

[woodgeek]

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.

 

[velvetfoot]

Carpet?

 

[mass_burner]

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.

 

[mass_burner]

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.