insulation...how much is too much

[jb daniels]

sorry to bring this up again...just confused. My cabin is solid concrete, floor and eight foot walls,and bermed. All the back and half of walls in ground with front exposed. I'm wondering if I insulate the interior stud walls too heavily,will this raise the chances of condensation or sweating on the walls ? When I tore out the old interior prior to remodelling, there was absolutely no insulation in the studs whatsoever. I lived there several years ago before gutting it, and never had a heating or cooling problem, so to insulate, or to not insulate...that is the question....

[John Raabe]

The berming is your insulation and probably has kept the surface of the concrete above the dewpoint during most of the heating season. That is why you have not seen any moisture damage.

If you do insulate your furred out walls you will need to have a good air barrier as the wall will now be more likely to be below dew point temperature and thus more likely to pull moisture out of the air. The air/vapor barrier should be on the warm side of the interior wall and is more important than the insulation.

When you insulate these walls you will also be isolating the thermal mass of the concrete to some extent (you will still have the floor). That means the place should be faster to heat up and faster to cool down. This could be a good thing or a bad thing depending on how you will use the place.

Insulation will mean less heating fuel, of course.

[jb daniels]

There is some good reading on hammerzone.com dealing with my current problem. Some other ideas there along with what I have read here...still confused. Should I insulate the walls around the concrete or should I not ? As stated before, there was none inside the old stud walls when I tore them out. There is a kerosene heater in there now until the stove gets installed, and when it warmed up, there was dew/condensation on part of the walls. So if I insulate, should I put up some kind of liner on the concrete walls, on the stuuded walls, or none at all...or just tear the place down and forget about it !!!    Frustrated at trying to do the right thing....

[Nelson, Tom P]

I seems like it would make a difference about  your climate- hot or cold and wet or dry, ground temp diferential to desired inside temperature, rate and temperature of the building fresh air ventilation, amount of ground moisture.  If you lived there for years with no insulation and no problems, what are you trying to fix?  If you want to use concrete mass to moderate temp swings inside, then insulate outside.  That might be a lot of work and expensive if using foam.  You already enjoy some benefit toward moderating temperature with earth berm. Calculate heating costs with and without insulation and price out the cost to insulate.  Maybe your condensation is from warm moist weather and no dehumidification.