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Discussion Starter · #1 ·
Hey guys

Need some help/advice.

Looking at insulating our own basement. 1979, poured concrete full height (8' approx) basement.

First choice is closed cell panels for the walls. Wanted to get opinions on if we could get away with not doing the floor to get the cost (and project size) down.

What's more important, walls or floor? Seems logical a lot more heat would be lost via the walls than the floor? Or will not doing the floor effectively make the wall insulation null and void?

Being 1979 (Nova Scotia, Canada) w ehave no idea whether the slab is insulated at all, and if so what type etc.

All help appreciated!
 

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Discussion Starter · #3 ·
The walls are probably average 6 feet below grade. It's a little lower on one end (small windows) and higher on the other (no windows). Average approx 6 feet below grade, wall height approx 8 feet.
 

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Discussion Starter · #5 ·
Nice idea! I have a laser thermometer for car work, so I can use that! I assume you'd also need the outdoor temperature too, and indoor??
 

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in my case, the basement temp is the same as the floor temp. wall temp varies just a little

what is your frost depth ?
 

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First solve all your water leakage problems. Then any closed cell foam R-2 per inch will help.
Insulating the floor is a waste of time and money. Unless the floor was poured with an insulative barrier your out of luck for the floor. I would guess close to ZERO chance in the 70's.
Once the water has been solved then it is up to you as to how much insulation you want to put in. More R means thicker furring. 6' underground you should be a pretty constant temp. Even that far north.
Guessing (WAG) basement is a constant ~45-50F.
 

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retired framer
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Ground temp most places is mid fifties with out insulating the floor you can expect the floor to be in the low 60s in a heated room . It may get a little warmer if you insulate the floor but as heat rises I doubt floor insulation is really worth the money and effort.
 

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Definitely the walls. The floor will be warmed by radiant energy from everything above and it will gradually warm the soil below and around the basement.
All water issues as stated need to be resolved.
Rigid foam board will usually be r-5 per inch and your local code requirements will tell you how much you need.

Bud
 

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Ground temp most places is mid fifties with out insulating the floor you can expect the floor to be in the low 60s in a heated room . It may get a little warmer if you insulate the floor but as heat rises I doubt floor insulation is really worth the money and effort.
Heat moves in all directions.
It may be worth it for comfort, not necessarily energy savings.
 

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Hey guys

Need some help/advice.

Looking at insulating our own basement. 1979, poured concrete full height (8' approx) basement.

First choice is closed cell panels for the walls. Wanted to get opinions on if we could get away with not doing the floor to get the cost (and project size) down.

What's more important, walls or floor? Seems logical a lot more heat would be lost via the walls than the floor? Or will not doing the floor effectively make the wall insulation null and void?

Being 1979 (Nova Scotia, Canada) w ehave no idea whether the slab is insulated at all, and if so what type etc.

All help appreciated!
The most important part to insulate is the exterior wall - above ground parts lose the most heat.

The best way to insulate a basement is to put 2" rigid foam directly against the wall - this creates a continuous thermal and moisture break, preventing moisture from the foundation from migrating into the rest of the wall assembly and basement while also preventing basement air from hitting cold surface and having moisture condense.

It can not be left exposed though.

Conventional batt insulation with plastic vapor barrier on warm side traps moisture from the foundation in the wall assembly, reducing r-value. This is not applicable to dry climates with low precipitation.
The plastic vapour barrier is needed though when doing batts only to stop house air from hitting surface.

You can have both rigid foam against the wall and batts between the studs, but the higher the r-value the batt insulation is, the thicker the foam has to be to stop condensation.

Really, the law of diminishing returns applies to insulation and the first r10 does most of it.

The canadian government does have rebates for high r-value basement insulation though.
 

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retired framer
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Heat moves in all directions.
It may be worth it for comfort, not necessarily energy savings.
The question is still how much comfort would be added and how much would it cost?
 

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retired framer
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Foam isn't cheap, that's for sure.
It's a matter of personal preference.

For a floor it would be like 0.5 to 1".
I would like to see something with a chart that says it makes a difference.
 

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I would like to see something with a chart that says it makes a difference.
Can throw some thin foam and desired floor material over a small area on the floor, walk on it and compare to an area without the insulation.

if its carpet, probably won't notice the difference.
 

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retired framer
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I would like to see something with a chart that says it makes a difference.
I have tile on concrete, the floor never changes. In the winter people complain about it being cold, in the summer the floor is nice and cool to walk on. The floor temp never changes more that 1 or 2 F and is likely warmer in the winter when the heat is on in here.
 

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retired framer
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Can throw some thin foam and desired floor material over a small area on the floor, walk on it and compare to an area without the insulation.

if its carpet, probably won't notice the difference.
For insulation to work you need heat on one side and cold on the other, or it is just another lump to walk on.
With all the companies that sell systems for the floor you would think we could find a chart of how much it helps.
 

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For insulation to work you need heat on one side and cold on the other, or it is just another lump to walk on.
With all the companies that sell systems for the floor you would think we could find a chart of how much it helps.
The foot has heat and the ground is cold - can do a test.

It's almost like debating if pot lights are worth it in a basement and asking for a chart on asthetics as it relates to lighting? (oddly enough i'm not a fan of potlights) or if there's a chart that says how much more comfortable the house will be with a modulating furnace vs a 100% on/off single stage. Come on. :rolleyes:

It's a matter of personal preference in the end.
 
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