Foundation with no Stem Wall, Footing, or Slab

[Bill Krajenski]

My house design calls for a foundation made completely of pilings which utilizes no stem wall, footing, or slab. This is very typical in the seashore area where I live where only pilings support the entire house. The outermost pilings are inset a foot or so from the perimeter of the outside wall’s main layer (so the pilings are not visible from the outside of the house) and cement board covers the gap from grade up to the siding. This creates a crawl space usually about two or three feet in height with no slab. There are horizontal beams that are bolted to the tops of the pilings connecting them together, and the first floor’s joists sit on top of these beams. The first floor’s platform joists are cantilevered out past the perimeter beams (equivalent to rim joist) by about one foot which allows all pilings to be hidden from an outside view of the house by the cement board. What is the best way to go about drawing this type of foundation? I can’t seem to build a foundation without having the program automatically generate a stem wall or a footing/slab, no matter which of the three foundation options I choose (piers, footings, or slab). Do I need to draw this entire type of foundation manually, if so, how do I get to “floor 0” with no stem wall or footings/slab being generated?

[Tommy Blair]

Can you post an image of what you're talking about? It almost sounds like a pier and beam foundation but then not.

[Bill Krajenski]

The image would show a normal stem wall foundation from an outside view, but in reality its only cement board (nailed to 2x4 studs from outside wall bottom to grade) showing where the foundation is with no stem wall below it at all. Yeah, its like a pier foudation, but the piers (or pilings) are only on the interior of the foundation - there are no piers on any outside wall.

[louis]

Bill,

Use the pier type foundation for this. Think outside the box on this one.

[DougM]

Bill, I'm very familiar with what you are talking about, I have a house over on LBI........ Is this what you want?

[DougM]

Couple more pics for those who don't know what Bill is referring to. I wish I knew how to make it a wall def. as usually these are put in rows, would be nice if you could draw a wall, set spacing of piers........hummmm, just got myself thinking again (yes I know, that can be dangerous) I wonder if a deck railing panel can be adapted to creat a wall with piers........Hummmmm?

[Tommy Blair]

Here is a sample of a pier and beam foundation that Louis is talking about.

[louis]

Tommy,

Look at the pier foundation in Chief. I bet you can figure out how to do this.

[Bill Krajenski]

DougM shows EXACTLY what I am looking to do. However, when I use the pier type foundation that everyone else is suggesting, I can't seem to eliminate the stem wall and footing altogether. I have no stem wall, footing, or slab in my foundation, only pilings on the INSIDE perimeter of the exterior walls. How can I eliminate the stem wall and footings?

[Curtis Johnson]

Bill: Sounds to me like you may need to forget about building the foundation and just create your below floor structure - whatever it is to be composed of - manually using PLine solids, soffits, beams, geometric shapes or however you can do it. You might even be able to use 3D molding plines for some of this. Are you doing a materials list for this project?

[Bill Krajenski]

Curt: No materials list is needed for the project. Do I build the "below the floor" structure when I am on Floor 1?

[pole creations]

Bill one way is you can draw walls on floor one and than insert floor height above terrain to give you clearance for crawl space .build foundation as monolithic slab then delete slab and draw some invisible walls to give you a room definition on floor level 0..... set floor height same as floor above and place posts and footings from framing box (you need to have the room definition via invisible walls to get pads to generate and then you can delete invisible walls....leaving exterior room polyline to define line of walls above
cheers zac

[DougM]

Bill, build foundation as usuall, make all walls invisible, shut off layer walls invisible and floor surfaces. Turn on 1st floor reference. Insert pilings per your specs, creat girder using polyine solid......Took me about 15 minutes. If you want the piling symbol, let me know.
Doug

[lbuttery]

floor surfaces

But you lose ALL your floor surfaces ???

All your interior camera views will be missing the floor ???

Lew

[DougM]

Not if you set them up on other layers, or put the basement floor on its own.... and if you can't (which I haven't tried)
There is other ways I'm sure of hiding floors. I think that that is the least of his dilemma.