pony wall framing, connecting

[Gary Pottenger]

There have been a lot of pony wall threads but my search didn't turn up anything.

Two problems - First the upper and lower walls are always framed identically (assuming they both have framing layers). Chief seems to use the upper wall for framing defaults ignoring the lower wall framing specs.

Second - the walls will not connect properly under a raised platform. What I'm trying to accomplish is to create a chase under a cantilevered 2ND floor that will frame out and finish out properly (not using soffits or solids). To do this I just raised the chase floor height and made the adjoining wall into a pony wall. Second floor not shown in images.

any help is appreciated

[Curtis Johnson]

I think I would put some posts and piers/footers under the overhang before I would worry about the pony wall issues. If you planned on adding them later, please disregard this post - it does look like you're just getting started.

There's are some improvements that could be made with pony walls, but we need to make sure we put all our ideas "on paper" and post it on the Suggestions Forum if we are seriously hoping the Chief programmers will evaluate them for inclusion in a future version. Their list is LONG!

[Gary Pottenger]

What I posted was a quick plan to show the issues. The real plan is a studio for my wife.

Doing the chase by making it a room with a raised floor allowed me to get the walls and platform framed up. Hanging the chase from the floor above lets me avoid running mechanicals through the I-joists and keeps it all within the conditioned space. I can manually move the framing around, it just seems strange that pony walls are framed so poorly.

What I can't seem to do is get the walls to join under the platform.

Any ideas?

[dshall]

What I posted was a quick plan to show the issues. The real plan is a studio for my wife.

Doing the chase by making it a room with a raised floor allowed me to get the walls and platform framed up. Hanging the chase from the floor above lets me avoid running mechanicals through the I-joists and keeps it all within the conditioned space. I can manually move the framing around, it just seems strange that pony walls are framed so poorly.

What I can't seem to do is get the walls to join under the platform.

Any ideas?

ooh, this is interesting, can you post the plan and let us know which walls you want to have connected.....this looks neato!

[Curtis Johnson]

Hi Gary:

Your recent images sure look a whole lot more reasonable then the first ones. I don't think you'll need double top plates for your chase box under the floor cant. I am wondering if you had some decent thickness PW sheathing on that canted wall, that you could utilize the sheathing to help provide attachment for the side studs by running it down past the upper floor connection (it would overlap the floor connection). You might consider using some spaced threaded rods to act as hangers to help carry the chase weight All that needs to be factored into your cant loads. You'll have to include the weight of your mechanicals in any calcs that are done. Looks like you may need to get an engineer involved on this one if the joist manufacturer doesn't provide some design service for this sort of thing.

I don't really know how the pony walls would help this situation even if they worked a little different. Do you have a CAD detail of how you think it should go together? If you don't have to show your model framing in 3D, it might be easiest to just deal with this with a couple of CAD details and be done with it ... once you figure the best way to do it.

I checked out the Boise Western Specifier document and it looks like their max. overhang for I-Joists is typically 2' unless some engineer puts his John Henry on a custom design. Even though your "just" attaching a chase, by the time you add up the framing, sheathing, hardware, mechanicals and insulation, you might find that you have too much weight for the joists without beefing them up somehow.

[Curtis Johnson]

Here's a some snap shots of some of the Boise info:

[Curtis Johnson]

Gary:

Here's a cant detail from the APA I just found:



Not sure how it may help you but with up to 4' max., it appears to be a stronger build than with I-joists.

[Gary Pottenger]

This project will get a full engineering work over as everything in my area does these days. I have a creative and realistic engineer that will make this work I'm sure. We will end up with enough hold downs and straps to change the earth's magnetic field but what else is new. I once worked on a townhouse remodel that had 105 MST48 straps that the contractor failed to install. We had to fix it during a remodel.

The main question is how do I get the wall below the chase to connect on each side. My plan zips to 6MB so I can't post it, will try to create in simpler plan.

[Curtis Johnson]

Gary:

Does the render 3D view show the corner problem as well? How about if you move the camera around at some different angles ... does the corner problem go away?

I just did a project with dormers and the shed dormer on the back of the house appeared to have the same issue but if I moved the camera around and got the angle just right, the exterior finish closed up the corner and it looked OK.

Can you just zip and post the plan that your first two images came from? It might be a bug - maybe you tried to create a situation that Chief can't solve.

[Gary Pottenger]

Simplest plan possible - dropped using pony walls - just moved one floor height up.
Shows the issue-
It seems to me that Chief determines the wall interconnection from the top down. Since the top part of the wall has another wall to intersect with it frames and sheaths to the intersection. When the wall continues below where the intersecting wall stops it does not "heal" the gap or change the framing.

[Curtis Johnson]

Gary:

It can be done but I am not sure how my solution will impact the rest of your "real" project.



My solution was to split it up with two different floors. The 2nd floor has to be Open Below. Then baloon the framing through for the lower rooms.

Chief will not close up the corners the way you went about it ... at least I couldn't get it to happen either.

[Curtis Johnson]

Here's a cross section view. I used my own dimensions. Note that for the 2nd floor, I adjusted the floor framing to 2x4 thickness.

[Curtis Johnson]

Gary:

Noticed a flaw with the wall framing going through the lower floor platform (I told it to do that initially thinking it was going through the floor platform above where the cant floor connects to the wall .... I was wrong). I also opened the lower and upper common walls and edited out the two top plates and the sill plate and lengthened the studs in the desired direction so that it looks like one continuous stud (except in X-section ... you see a line there where they join).

Hope this may give you a different direction to attack this from. I rest my case. Hopefully someone has a better solution.

[Gary Pottenger]

I went through most of the same editing. Noticed that frame through platform means both platforms and edited it out.

Real world - I have a 2nd floor covering both- so the open below solution is a problem.

I think maybe its time to call tech support.

Thanks for looking at it - figured that this was not new and I was doing something stupid.

[Curtis Johnson]

Gary:

Maybe for your exterior render views you just stick a polyline solid over the corners and make it your exterior finish material .... might take a little jiggling to get it place right. For elevations sent to LO, you'd have to edit some lines out for sure.

Let us know if tech support has a good solution ... and what that solution is.