Exterior Basement Insulation

[BleedingBlue]

Background - I bought a house in Indiana built in 2004 with an 800 sq ft finished basement; however, after living in the house several years I have determined there is no insulation on the interior concrete walls, just drywall. The temperature drops to ~57 degrees in winter. It does have three heating ducts that make very minimal impact.

Question - what are my options to insulate the above grade exterior exposed concrete? I would rather not gut the basement to insulate the walls or excavate anything on the exterior.

Thanks!


Sent from my iPhone using Tapatalk

 

[77thor]

I would add foam sheet insulation to the exterior walls down to the frost line.

 

[mike93lx]

Background - I bought a house in Indiana built in 2004 with an 800 sq ft finished basement; however, after living in the house several years I have determined there is no insulation on the interior concrete walls, just drywall. The temperature drops to ~57 degrees in winter. It does have three heating ducts that make very minimal impact.

Question - what are my options to insulate the above grade exterior exposed concrete? I would rather not gut the basement to insulate the walls or excavate anything on the exterior.

Thanks!


Sent from my iPhone using Tapatalk

How much concrete wall is exposed? How will you finish it? If just a small amount is above grade insulating just that won't do much.

Even with insulation on my sheathing and siding, I don't have much space to insulate the foundation before it would be proud of the walls.

 

[Showkey]

Standard build practice in my area is 1.5-2.0” pink sheet foam on the outside against the wall. 8’ panels are the preferred product on the full wall. Exposed foam gets treated with cement based plaster type covering.

Common retro fit is dig 6’ down drop in 2” foam and back fill. Lip at the top of the foam must flashed under the siding to stop water from getting between the foam and wall.

Many areas it’s code for new homes.

https://www.energy.gov/energysaver/weatherize/insulation/where-insulate-home

 

[mike93lx]

Standard build practice in my area is 1.5-2.0 pink sheet foam on the outside against the wall. 8’ panels are the preferred product. Exposed foam gets treated with cement based plaster type covering.

Do they hang the sill out over the wall, use exterior insulation on the framed walls or something else?

 

[BleedingBlue]

How much concrete wall is exposed? How will you finish it? If just a small amount is above grade insulating just that won't do much.



Even with insulation on my sheathing and siding, I don't have much space to insulate the foundation before it would be proud of the walls.

There is pretty roughly 10” above soil. I wasn’t sure how to insulate it or if it would provide much value but was curious.

 

[BleedingBlue]

I would add foam sheet insulation to the exterior walls down to the frost line.

Are you referring to the standard pink board? I was hoping for something more discreet that would blend in if possible

 

[The Cobbler]

well, just to discuss the value of basement insulation...
I went from zero basement insulation to R-13 and R20 in the joist bays .

with no insulation, 4 vents opened full in winter months, I was cold down there with a sweater on. windows were new

with full insulation, 2 vents partially opened,2 closed fully, it is comfortable without a sweater .
basement is unfinished .

 

[mike93lx]

There is pretty roughly 10” above soil. I wasn’t sure how to insulate it or if it would provide much value but was curious.

I wouldnt bother if you don't want to go below grade. Insulating the rim board with foat sheet and expanding foam, plus air sealing will be more effective IMO

 

[GRivera]

Are you able to drill a hole in the drywall and do blown-in insulation?

 

[BleedingBlue]

Are you able to drill a hole in the drywall and do blown-in insulation?

Is there blown in insulation that is waterproof that could be used? Assuming if i used standard blown in insulation it would mold


Sent from my iPhone using Tapatalk

 

[Bretny]

I'm not aware of any blown In that you can use in a wet environment like that.

Insulating the outside wall will put the concrete in your conditioned space and not help. Take down the drywall. It wasn't done right to begin with so taking a look behind should be done.

We did this to a family members basement. Pulled the studs 1in away from the concrete for a thermal break then filled the bays with foam board. It's very very well insulated. It's a walk out on one end and 3ft underground at the deep section.

 

[ripperd]

Insulating the outside wall will put the concrete in your conditioned space and not help.

Not true at all. And potentially even a better way to do it, since the outside wall is a very large thermal mass and will keep the temperature more even in the basement. But that is a huge job to retrofit.

We have a full basement with poured walls that were insulated and waterproofed from the outside at time of construction. The inside is bare concrete. There is only a single heat vent in the basement (it is unfinished). The basement stays only about 3-4 degrees cooler than the main floor. It is dry and fantastically comfortable down there. Very unlike the basements of older houses.

 

[Showkey]

Do they hang the sill out over the wall, use exterior insulation on the framed walls or something else?

Here’s a pic when the cement coated pink foam insulation is installed during original build. Retro fit foam after the fact would require a flashing under the siding and over the foam. The foam is only coated where it’s exposed to UV, sunlight and physical damage, coated for looks and protection.

Are you able to drill a hole in the drywall and do blown-in insulation?

Moisture coming through the basement walls and the blown insulation could be a real bad combo.