Hello. I am seeking guidance for improving the floor support in an existing structure, please. Here is a photo of the west end of the structure, from the outside:
![Image]()
This is an old carriage house, circa 1908, in great shape. Existing joists run north-south (left to right in the photo) and are 1.5"X13" (exact measurements), 16" OC. The span from wall face to wall face, inside, north to south, is 22'. All is well for the upstairs unit: solid floors, not bouncy, etc. I believe the installation as-is still complies with current span charts. The ground level of this building is basically just garage / storage space.
My concern is with respect to the first 4' of the joist framing from the west end of the building. During some work on the upper unit about 15 years ago or more, a 3" raised platform at the west end of the unit was removed, uncovering an opening in the floor. Best guess: in the old carriage house days, there was probably a lift of some sort. Once this was identified, some joist framing was added to put in a proper subfloor so the upstairs floor would be all at one level. Here's a photo from below that may help with visualizing that:
![Image]()
At the time, I was not completely comfortable with the last 4' of this room being supported by, effectively, one joist, so being very conservative I ('temporarily') added the support columns that you see in the photo. I'm now finally getting back to this, wanting to get rid of those columns to better use the garage space. I assume the framing as it stands is not ideal. I'm open to being convinced otherwise, but my gut tells me (in the absence of engineering input) that this is not the best implementation.
Following my current thinking, for now at least, I would like to add some joists and be done with it, removing those supports once and for all. I've considered a few options:
Before concluding, there is one further detail worth asking about: the north side of the building appears to be balloon framed with 2X6 members. In the old days, was it acceptable (apparently?) to simply nail the joists, in a balloon framed situation, to the vertical 2X6s? I've only opened up the last 4' of the ceiling, but that is what I'm seeing, and I assume that continues all the way to the east. Since I will be placing the added joists of whatever variety in off-wall-framing locations (i.e., not perfectly aligned with the 2X6 members), is it acceptable to simply build my own "top plate" by adding blocking / framing (plus hangers) between the two adjacent 2X6 members? If so, I would just block them, in that fashion, at the right height to properly support the new and shorter joist members at the right level. Does that sound reasonable?
I apologize for length, but it's a complicated scenario and I meant to be as clear as possible.
Thank you.
This is an old carriage house, circa 1908, in great shape. Existing joists run north-south (left to right in the photo) and are 1.5"X13" (exact measurements), 16" OC. The span from wall face to wall face, inside, north to south, is 22'. All is well for the upstairs unit: solid floors, not bouncy, etc. I believe the installation as-is still complies with current span charts. The ground level of this building is basically just garage / storage space.
My concern is with respect to the first 4' of the joist framing from the west end of the building. During some work on the upper unit about 15 years ago or more, a 3" raised platform at the west end of the unit was removed, uncovering an opening in the floor. Best guess: in the old carriage house days, there was probably a lift of some sort. Once this was identified, some joist framing was added to put in a proper subfloor so the upstairs floor would be all at one level. Here's a photo from below that may help with visualizing that:
At the time, I was not completely comfortable with the last 4' of this room being supported by, effectively, one joist, so being very conservative I ('temporarily') added the support columns that you see in the photo. I'm now finally getting back to this, wanting to get rid of those columns to better use the garage space. I assume the framing as it stands is not ideal. I'm open to being convinced otherwise, but my gut tells me (in the absence of engineering input) that this is not the best implementation.
Following my current thinking, for now at least, I would like to add some joists and be done with it, removing those supports once and for all. I've considered a few options:
- Find 24' 2X14 members, rip them to 13", cut channels in the existing framing as needed, install three of them 12" OC. It seems 2X14 members in that length may be hard to find, however. Ripping them at that length would not be fun.
- Use open web joists. I've done the homework, but the details escape me at the moment. I think I may need two or three, and they'd be shorter than 13".
- Similarly, I-joists, two or three of them, shorter than 13", as well.
- LVLs. Also similarly, perhaps two of them, maybe 3, also shorter than 13".
- LVLs Part II. Sister one or two of them to the joist off of which the last four feet of the upstairs room hangs, giving it the strength to make the rest of the framing to the west a non-concern. I've not checked with an engineer, however, to determine whether the math works on this. Between paying for an engineer's input and installing new joists, I've been leaning towards installing the new joists. Perhaps someone here can comment convincingly, however, on whether this approach might work fine. It's potentially the easiest option, though my conservative nature likes the other approach better.
Before concluding, there is one further detail worth asking about: the north side of the building appears to be balloon framed with 2X6 members. In the old days, was it acceptable (apparently?) to simply nail the joists, in a balloon framed situation, to the vertical 2X6s? I've only opened up the last 4' of the ceiling, but that is what I'm seeing, and I assume that continues all the way to the east. Since I will be placing the added joists of whatever variety in off-wall-framing locations (i.e., not perfectly aligned with the 2X6 members), is it acceptable to simply build my own "top plate" by adding blocking / framing (plus hangers) between the two adjacent 2X6 members? If so, I would just block them, in that fashion, at the right height to properly support the new and shorter joist members at the right level. Does that sound reasonable?
I apologize for length, but it's a complicated scenario and I meant to be as clear as possible.
Thank you.
