What are the consequences of a well insulated basement?

james_007June 11, 2011

My basement is an old (more than 50 yrs) poured concrete basement, unfinished, no water issue but has lots of effloresces (moisture issue). It is a dry "warm" basement in the winter and dump "cool" basement in the summer (didn't use dehumidifier yet). There is no heating during the winter but the temperature always keeps at the range of 52 - 62 degree all year round.

I am thinking about finish it and have done lots of research about how to do it. I agree the rigid foam for wall and floor is the best way to go for the insulation. A well insulated basement is good to eliminate condensation in the summer but it is NOT good to get the temperature from the ground during the winter. I am worrying that we have to put heating system in the basement to avoid pipe frozen during the long winter after the insulation (in MA). If that is the case, why we need to insulate it so well?

How about the summer, do we need air conditioner down stair after the insulation?

Worry about condensation during the summer for an un-insulated basement? Use dehumidifier to keep a dry environment may be enough.

So if we think 52 - 62 degree is good in basement, we can just finish the basement without any insulation and vapor barrier. There will be no moisture and condensation problem in winter. During the summer if the dehumidifier works as expected, there should be no moisture and condensation issue as well.

What's your experience and opinion about this?

Thank you for reporting this comment. Undo

First off, sufficient rigid foam serves as a vapour barrier in your climate.

Secondly, if you're satisfied with 52-62 degrees F. in your basement, there's no sense in insulating below four feet below grade. The big heat loss in basements occurs in the above-grade portion of the basement, both through leaks and low R factors.

Insulated basements in your climate normally don't need ac in the summer.

Here is a link that might be useful: Building Science Corp on basements

    Bookmark   June 15, 2011 at 10:48AM
Thank you for reporting this comment. Undo

That efflourescence means that water is coming in through the walls. What will that water do when it comes in and hits the foam?

    Bookmark   July 1, 2011 at 7:49PM
Thank you for reporting this comment. Undo

Extruded polystyrene foamboard is virtually unaffected by moisture. That's why it's even used for floating docks.

But, yes, the efflorescence indicates that there is probably excessive moisture reaching the foundation and that should be remedied.

    Bookmark   July 4, 2011 at 3:02PM
Sign Up to comment
More Discussions
Basement tile grout sweating
Hi Experts, We have a new house (1 year old, Hamilton,...
Joe Regular
water seeping through floor?
I have a finished walk out basement. After several...
What kind of ceiling to do?
We are wanting to finish out basement rustic/lodge...
Basement Plans Thoughts?
Hello, Planning to finishing my basement and hoping...
Walkout Basement in Texas
Greetings to all! I have a sloping lot on Lake Conroe...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™