building question (house, construction, contractor)

[unionjack3902]

With building on permafrost with post and pier, how do you construct the floor, 2x12, type of and thickness of inslation vapor barrier, etc.

[Marty Van Diest]

You can still have problems building on permafrost even if you do the post and beam building method. Just clearing the land for building can make the permafrost thaw over time. Some people put concrete pads on undisturbed soil just below the overburden and build a leveling system into the construction so that they can easily jack up each pier seperately.

Insulate the floor with at least 12 inches of fiberglass. Put the vapor barrier between the insulation and the interior of the house...just under your subfloor.

[RayinAK]

Some people use posts that are adjustable, which should work for a certain period of time. But sometimes portions of the house sink past the point of adjustment, at which point a hydraulic jack is the only option. Some other times the sinking is just too fast and deep to do much about it. A coworker of mine has a house on permafrost (on posts), and every four or five years he has to get a contractor to raise one end of the house to keep it level. They just keep on "shimming" that end of the house, and repairing the cracks that develop on the sheetrock inside the house. He has had problems with the water and sewage pipes freezing under the house, so he decided to dig down around the pipes about six feet, and build a sort shaft with 4" blue foam blocks and 2"x4"s from the ground to the bottom of the house. The idea is to keep this area slightly warm by using heat tape on the pipes.

[Dakster]

I guess it would be too difficult to get a pile driver to set them in the first place? Although I guess if you could do that you would be able to dig & pour a foundation.