Second floor addition to house framing??

[Daneman]

I'm looking for a detail of adding TJI's for a new second story floor above existing 2x6 ceiling framing. I want to keep some space between the new TJ's and old 2x6's so existing wiring can remain in place and so the new TJ's can span in either direction. Need to transfer lateral loads from new framing through the existing bearing walls to the foundation as well. Thanks in advance!  

[OttawaP]

Just add a 2x6 plate all around exterior and over l/b walls. In the real world some levelling will be required..

[DRAWZILLA]

here is one that I have used for 40 years, Just adjust your floor platform.

Framers love it b/c you can get large beams in the floor system

 

[DRAWZILLA]

some more info. One problem is that you cannot adjust the direction of the ceiling joists, you would have to fix the sections manually, if you don't frame the ceiling joists, you can add your own in the sections.

 

[dshall]

1 hour ago, DRAWZILLA said:

some more info. One problem is that you cannot adjust the direction of the ceiling joists, you would have to fix the sections manually, if you don't frame the ceiling joists, you can add your own in the sections.

 

 

I wonder why we can't specify the direction of the ceiling joists and the floor joists separately.  Hey P.,  maybe this could be a suggestion.

[DRAWZILLA]

already done it for some time. Probably at the bottom of the list.

[javatom]

Perry is on the right track.  It will need some serious hardware to prevent a hinge point problem.  When I have done this in the past, the engineer sometimes specifies 16" timber screws through the beam and into the original top plate.

[DRAWZILLA]

My structural engineer says , don't need that

[dshall]

9 minutes ago, DRAWZILLA said:

My structural engineer says , don't need that

 

Mine too.

[javatom]

Your engineer is doing it with the ltp4 hardware at 16" oc each side.  Its the same end result.  The screws are just a faster (but more expensive) way to do the same thing.

[Alaskan_Son]

1 hour ago, dshall said:

 

I wonder why we can't specify the direction of the ceiling joists and the floor joists separately.  Hey P.,  maybe this could be a suggestion.

 

You CAN specify different directions for a DROPPED ceiling and the floor joists above. For the situation in this particular thread however I think an additional floor is probably the most correct way to go about it. 

 

P.S.  In some situations you can also explore the possibility of specifying your room as a deck and then using the joists and planks to frame your floor system.  Would probably require a little cleanup and would likely require using a material region for the floor surface...Actually, probably faster to just frame the floor manually, but it's a fun thought anyway.

 

P.P.S.  Another option might be to use a ceiling plane. 

[dshall]

12 minutes ago, Alaskan_Son said:

....... For the situation in this particular thread however I think an additional floor is probably the most correct way to go about it. ........

 

If you have tried the extra floor method,  you would of discovered some of the limitations.....  doable.......  but a lot of work.  

 

Think about how your stairs will work ......

[Alaskan_Son]

11 minutes ago, dshall said:

 

If you have tried the extra floor method,  you would of discovered some of the limitations.....  doable.......  but a lot of work.  

 

Think about how your stairs will work ......

 

 I typically don't throw ideas out there that I haven't personally used or tested without immediately disclosing the same but in this case you are correct. I have NOT tried it.   I do understand how chief works though and I understand the structural concepts as well.  

 

 I was just thinking through it logically.   That space between floor structures isn't any different than an extra floor that has no interior floor wall or ceiling finishes.   I assume it would have some cleanup to be done but in my mind it still seems like the MOST correct automated method for a  situation with stacked floor systems that have different joist layout and/or directions.    I guess I'll have to test it out one of these days. 

[dshall]

Perry is probably the expert on this.  I have used the extra floor method,  and it worked fine,  but there is probably a better way.

 

I think the better way would be probably what Perry does which is the ceiling and floor is one assembly.   The downside of this would be all joist run the same direction.  

 

Another method would be ceiling planes.....  as you suggested....  that might get a bit fussy if you want the ceiling joist to sit on exterior wall which is what you would want.....however then you might not get the finish on the exterior wall... unless the floor ceiling assembly is defined as the entire thickness  (24"?) but the ceiling joist layer is simply NO MATERIAL......  (very poorly explained but I think I understand what I was trying to say).

 

Oh shoot,  the answer is to let us define direction of both ceiling joists and floor joists without the big workaround.  Of  course this would mean we would need BEARING LINES for both ceiling joists and floor joists.

 

I guess I am lucky,  I rarely keep ceiling joists on for a second floor addition.  I tear off ceiling joists and replace with 14" deep tji's.

[DRAWZILLA]

extra floor doesn't work at all without  going to extra measures with stairs. We also need the existing plate lines to stop at the 1st floor ceiling as they are in real life, extra floor doesn't do that. believe me my way is better, less workarounds. you can place the 4x8 block up and adjust the height to get it between the floors.

Michael if you ever did this you would know.

 

[Alaskan_Son]

4 hours ago, dshall said:

think the better way would be probably what Perry does which is the ceiling and floor is one assembly.   The downside of this would be all joist run the same direction.  

 

To me, the lack of control over joist thickness, joist spacing, and joist direction makes the multi-layer assembly a non-starter.  That's just me though.  I know a lot of guys don't care quite as much about 3D accuracy as I do.  I like my 3D model to be accurate though and so FOR ME, I'm still thinking the multiple floor solution is best. 

 

I DID just try the method out too and I'm not sure I see the problem with the stairs that you guys speak of.  What's the problem?  Can you elaborate a bit?

 

I haven't messed around with it a whole lot, but the one problem I HAVEN'T been able to quickly sort out is how to get a single plate to automatically frame for my 1-1/2" tall floor. It's not too big a deal.  It's easy enough to throw a few extra plates in there.  Just a limitation I noticed. 

 

 

[DRAWZILLA]

framingMy 3d models are perfect except for that 2story over a 1 story, never show a 3d view anyway, if you just don't include a framing material for the existing ceiling, works like a charm-no sweat. just fill in the ceilings in the sections if they are in a different direction- very easy to do.

[dshall]

2 hours ago, Alaskan_Son said:

 

To me, the lack of control over joist thickness, joist spacing, and joist direction makes the multi-layer assembly a non-starter.  That's just me though.  I know a lot of guys don't care quite as much about 3D accuracy as I do.  I like my 3D model to be accurate though and so FOR ME, I'm still thinking the multiple floor solution is best. 

 

I DID just try the method out too and I'm not sure I see the problem with the stairs that you guys speak of.  What's the problem?  Can you elaborate a bit?

 

I haven't messed around with it a whole lot, but the one problem I HAVEN'T been able to quickly sort out is how to get a single plate to automatically frame for my 1-1/2" tall floor. It's not too big a deal.  It's easy enough to throw a few extra plates in there.  Just a limitation I noticed. 

 

 

 

The stairs want to stop an second floor,  not the third floor.  And then if you send third floor to layout you don't see stairs at first floor unless you use ref sets.

 

If it works for you,  that is awesome.  I am lucky this has come up only a couple of times in 10 years.

[justmejerry]

If you use deck room to create ceiling joists for first floor and another floor above that set to whatever you want to use for new 2nd floor

space, it will let you manipulate joist direction. You would need to use 0" thickness for for deck planking layer for it to work and set deck room height to whatever thickness materials to be used for lifting new floor assembly up.

 

3 hours ago, Alaskan_Son said:

I HAVEN'T been able to quickly sort out is how to get a single plate to automatically framing for my 1-1/2" tall floor.

Michael,

I believe the wall would need to be at least twice the thickness of a plate for it to be considered a wall to be able to be drawn.

[Alaskan_Son]

6 minutes ago, justmejerry said:

Michael,

I believe the wall would need to be at least twice the thickness of a plate for it to be considered a wall to be able to be drawn.

 

Thanks Jerry, I figured it was something like that.  I just didn't dig too deep. 

 

Creative solution with the deck framing too.  I'd say if a person wants to get into the business of skinning cats that they might start out by first learning to use Chief Architect : )

[DRAWZILLA]

Thanks Jerry but that condition would not be approved here, codes for short pony walls like that would have to be a solid beam to work. Hinge effect is also in play