Results 1 to 6 of 6

Thread: Foundation question

  1. #1

    Default Foundation question

    I'm planning on a building a crib type foundation with railroad ties crisscrossed on top of pads of gravel, sitting on top of the existing vegetation with permafrost underneath. My question is, would there be any advantage to running three beams underneath my subfloor as opposed to just using beams for my rim joists on my subfloor? The reason why I am thinking about doing this is #1 to save money, and #2 because the beams as my rim joists will give more support underneath my log walls and it will give me something solid to attach too with my first run of logs.

  2. #2

    Default

    If you are speaking of 3 beams the full length of the cabin verses 2 along the outside edge of the cabin. You would be much better to go with the 3 as that would give you support for the end wall in the middle. You should keep the outside ones under the wall .

  3. #3
    Member Rock_skipper's Avatar
    Join Date
    Mar 2008
    Location
    Deltajct
    Posts
    2,499

    Default

    Building on permafrost is always a tricky question. In the villages we put down pillings, greesed the pipes an wrapped them in plastic so that the frost would move up and down without moving the house's

    If its just a small cabin, I don't see a problem with your design except that you are talking about adding gravel to the base. That will attract sunlight on one side of your house that gets sun and transfer heat into the ground and start a heating process that over a few years will likely tend to make that side of your house to settle, just my thoughts..

    ( Some styrafoam under the gravel might help. )

  4. #4
    Supporting Member iofthetaiga's Avatar
    Join Date
    Oct 2009
    Location
    Tanana Valley AK
    Posts
    7,218

    Default

    Quote Originally Posted by Bushwhack Jack View Post
    I'm planning on a building a crib type foundation with railroad ties crisscrossed on top of pads of gravel, sitting on top of the existing vegetation with permafrost underneath. My question is, would there be any advantage to running three beams underneath my subfloor as opposed to just using beams for my rim joists on my subfloor? The reason why I am thinking about doing this is #1 to save money, and #2 because the beams as my rim joists will give more support underneath my log walls and it will give me something solid to attach too with my first run of logs.
    I think I understand what you're asking, Jack. I believe you're building with 3 sided logs, yes? If it were me, I would support the structure under the long walls only, hang my floor joists in hangers inside the first course sill logs or beams, apply my subfloor decking to tie everything together, then continue up on top of that with my log walls. Simple, clean, and bomb-proof strong; easy to re-level as necessary.
    ...he who knows nothing is nearer to truth than he whose mind is filled with falsehoods & errors. ~Thomas Jefferson
    I would rather have a mind opened by wonder than one closed by belief. ~Gerry Spence
    The last thing Alaska needs is another bigot. ~member Catch It
    #Resist

  5. #5

    Default

    Quote Originally Posted by Big Bend View Post
    If you are speaking of 3 beams the full length of the cabin verses 2 along the outside edge of the cabin. You would be much better to go with the 3 as that would give you support for the end wall in the middle. You should keep the outside ones under the wall .
    That makes sense big bend. But I forgot to mention that I will have railroad ties under the middle of the rim joists on all four walls so that the walls are supported well. But I didn't think it was really necessary to have a beam running through the middle of the floor for a small cabin (16 x 20).

    Quote Originally Posted by Rock_skipper View Post
    Building on permafrost is always a tricky question. In the villages we put down pillings, greesed the pipes an wrapped them in plastic so that the frost would move up and down without moving the house's

    If its just a small cabin, I don't see a problem with your design except that you are talking about adding gravel to the base. That will attract sunlight on one side of your house that gets sun and transfer heat into the ground and start a heating process that over a few years will likely tend to make that side of your house to settle, just my thoughts..

    ( Some styrafoam under the gravel might help. )
    Thanks for the advice Rockskipper. There wouldn't be a whole lot of gravel. Just a small gravel pad underneath the railroad tie cribbing for leveling purposes. Because the ground is irregular tundra.

    Quote Originally Posted by iofthetaiga View Post
    I think I understand what you're asking, Jack. I believe you're building with 3 sided logs, yes? If it were me, I would support the structure under the long walls only, hang my floor joists in hangers inside the first course sill logs or beams, apply my subfloor decking to tie everything together, then continue up on top of that with my log walls. Simple, clean, and bomb-proof strong; easy to re-level as necessary.
    I believe you and I are talking about the same thing Taiga. Basically instead of using OSB or LVLs for my rim joists I would just use 4 x 12 beams for my rim joists. Then I am thinking I won't have to use beams underneath my floor and the joist hangers can attach to the beams (rim joists), my 3/4 OSB T&G on top of that. Then my first course of logs. And my first course of logs can be screwed down to the rim joists (beams) with some heavy duty lag screws or timberlok screws. Thanks for your input.

  6. #6
    Supporting Member iofthetaiga's Avatar
    Join Date
    Oct 2009
    Location
    Tanana Valley AK
    Posts
    7,218

    Default

    Quote Originally Posted by Bushwhack Jack View Post
    I believe you and I are talking about the same thing Taiga. Basically instead of using OSB or LVLs for my rim joists I would just use 4 x 12 beams for my rim joists. Then I am thinking I won't have to use beams underneath my floor and the joist hangers can attach to the beams (rim joists), my 3/4 OSB T&G on top of that. Then my first course of logs. And my first course of logs can be screwed down to the rim joists (beams) with some heavy duty lag screws or timberlok screws. Thanks for your input.
    That's what I'd do. Crib foundation every ~10 feet on the long sides (3 cribs on each long side), and free span the 16 feet with your floor joists.
    ...he who knows nothing is nearer to truth than he whose mind is filled with falsehoods & errors. ~Thomas Jefferson
    I would rather have a mind opened by wonder than one closed by belief. ~Gerry Spence
    The last thing Alaska needs is another bigot. ~member Catch It
    #Resist

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •