Another foundation question

[buylocalmaine]

We live in Maine where frost level is 4-6 feet. Our building site is on ledge with about two feet of soil. We plan to build the 14'x24' little house. We have to do it as inexpensively as possible. Any suggetions on what type of foundation? Some people tell us that since we're so close to ledge we shouldn't have a major shifting problem. The soil is pretty sandy. I don't know who to listen to.

[jdew]

Not really following you.  You mean it's close to a ledge?  Like a cliff or something?

If your soil is extremely well draining then the potential for frost heave is pretty small.  But personally I wouldn't want to take that chance.

What about a frost protected shallow foundation?  Do a search for it, lots of information on the net.

Also, if look for it on this site, there is a method of building with a post and pier system, which is quite a bit cheaper than a traditional basement or crawl space foundation.  This may work well for you depending on the size you are trying to build.

[John Raabe]

I think in parts of New England the "ledge" is a layer of rock just under the soil line rather than the more common use of the word meaning the edge of a dropoff.

If I understand BLM's post the soil on top of the rock is well drained. If that soil and the underlying rock are stable (and you are in an area with low potential of earthquake) then the shallow foundation of the Little House project would be the way I would build a small inexpensive house. All the information is in the plans.

You might checkout this house to see how they did the foundation: http://www.countryplans.com/nicolaisen.html

Here is a link to some of the experiments others have done with insulation on shallow post and pier foundations.

http://www.countryplans.com/bbs/messages/2985.html

[Daddymem]

Yeah, ledge is what we call bedrock at or near the surface.  Here in New England sometimes it is above the ground, sometimes it is shallow below the ground.  This is basically the stuff from which our soils originated when the big glaciers stomped around.

[jdew]

You can't get much more solid then bedrock.

[buylocalmaine]

Sorry to have been so vague. Our soil IS very well drained and it's about three feet deep. Then we hit ledge, or bedrock. We are only able to afford post and pier foundation. I mean, someday we'll be able to afford to put in a cellar but we need shelter by the fall. Thanks for the help.

[Amanda_931]

Can you pin to your ledge rock?

(I couldn't here--too apt to be thin with shale under it)