Insulate or not?
 

Hi All! I"m back, and with a question. My basement is about 2/3 below ground level. As such it remains cool in the summer and not freezing in the winter. I'm about to remodel the basement. Should I insulate between the block and drywall or not?

Other info: Basement is dry
Walls have dry-loc
I live about 30 S of Cleveland, OH

Your opinions as well as your experiences and knowledge are appreciated--Ed

Yes, most definitely, yes. Even if you don't use the basement, insulation will make the floor above feel warmer. Besides, you've really only got one chance. Once the drywall is up and the walls are finished, it will be too expensive to go back and try to insulate it.

One of the best things you can do for your basement is to insulate, at least, the inside walls around the entire perimeter. Even if you will never finish your basement, insulating the inside walls of the outer perimeter of your basement will lower your heating bills quite a bit. And the other thing you can do once the insulation is done around the outer walls is to put insulation right into the top part of the wall where the concrete and the actual house meet. You could spray that expanding foam around the seams and then just fill the rest in with regular insulation. It will make it a lot more bareable to go into the basement and your furnace won't have to work as hard to heat the rest of the house.

I'd totally agree with the others here. The r-value of concrete and block is just horrific as far as insulation goes. Anything you can do to insulate the basement is going to be worth it.

ColoradoENERGY.org - R-Value Table

Yes, and no...
 

Hi all,
Of course the practical and cost effective way of insulating would be to insulate the inside of the walls. You shouldn't even have to insulate the full length, the biggest bang for your buck will be the portion above ground, followed by the next few feet under the ground. However, it's not the best for keeping the temperature constant...

From an "thermal mass" point of view, you should NOT insulate the inside of the walls. That concrete is great at holding it's temperature and why give that advantage to the outdoors?
http://i378.photobucket.com/albums/o...r/untitled.jpg
You should insulate the outside of the walls from the first floor down, and dig around the house to put in insulation at an angle around the house. This isn't practical for existing homes, so should be done when a home is built, but could be done afterward. I have an example of this type of design in practice. It was a test house built in Platteville, Wisconsin in the 70's. The home is awesome! I may have to make a thread about it.

Insulating the outside of the walls would be better. However, insulating the inside of the walls is still a huge benefit vs not having insulation.

I also see the benefit of the design in your picture, but also dislike it. There is still a huge amount of surface area of the house touching soil which will carry away heat. Ideally, you want the entire house enveloped in insulation.

Superinsulating a house does have advantages, but if you think about it, your soil is a huge thermal mass, it takes in outdoor heat in the summer gives it to the house in the winter, like a passive geo-thermal heat pump. Yes 58 or 60 degrees is pretty cool, but a sweater fixes that. If you are not paying to heat or cool the basement, you can achieve near underground temperatures year round by insulating correctly. That being said, I would go ahead and recommend insulating the inner surface of the walls just because it's so much easier.

No one ever regrets adding insulation unless it is so much that they no longer have space inside of their house.
on the super insulated house that i worked on we did both kinds of insulation outside, flat up to the walls if we had those walls and could easily get at them and running down and away from the house, the idea behind that type is to keep the frost away from the foundation walls so the foundation can take advantage of the 50 degree earth.
On NPR today they were talking about insulation like you want to do inside your basement and they suggested building your stud wall an inch or so away from the cement walls and spraying foam to create a monolith of foam around the wall and allowing you to add another inch of foam, if they were really flat walls you could get the same affect with an inch of foam board behind the studs.

Hey Ryland, can you start a thread on some of the superinsulated houses you've done...even the solar stuff that Daox was telling me about? I know I'd be interested in any info you have and pictures if you have any. What, how and why you did such and such...etc...