woodisgood

I would like to here some different thoughts on this subject. Way back when hand laid stone was the standard foundation there wasn't any footer drains, heat loss wasn't a factor, and proper site drainage overlooked. Frost push rarely happened. Now that energy savings is at the thought of every HO do we need to worry when this situation comes up. My thoughts are that the foundation wasn't designed to handle deep frost push which you may get by insulating the walls of the foundation. Keep in mind that soil moisture content maybe higher than a newer foundation. Maybe I'm reading too much into this?

concretemasonry

Where are you that you think the frost may be that big of a problem?

Interior or exterior insulation?

What kind of natural soil and backfill do you have?

Around here we have 4' to 5' of MAXIMUM frost penetration. The actual penetration can be much less, especially depending on the location and exposure. It will be much deeper where there is traffic and can be zero at -20F if there is snow.

Exterior insulation of foundation walls has been fairly common around here for years with no common problem due to frost, even for 12" unreinforced block basements. If you insulate, the only type to use is EXTRUDED polystyrene and not EXPANDED polystyrene (the cheap white stuff that is only good for coffee cups).

The total annual energy savings for an insulated basement is not as great as you would think, you you do get confort if it is finished.livable space.

__________________
Dick

Engineer, designer and consultant recently active internationally on construction and design in about 35 countries.

woodisgood

I live in northeast Pa., we can have a frost of three to four feet at worst. I have seen many block walls push, mostly because of pour drainage. We have many old foundations many of which you can see daylight through the joints of the dry laid field stone. With out insulation you won't get deep frost against a wall like you will with an insulated wall. Once you get a snowfall to stay there's no frost after a week or two. What I've seen alot is spray foam insulation to fill all the cracks from the inside but haven't been back to see if there's any movement.
Thanks Lou