Sloping wood framed floor....cause?

[mfstructural]

I looked at a townhouse unit the other day where the client was looking for an assessment of why the floor was sloping and if it's safe. The client was interested in buying this unit and wanted to make it was safe. I've attached some pictures.

The sloped floor is about a 4 foot by 4 foot area. Floor sloped about 1.5 degrees. A portion of the foyer in image 7638 is framing over the entrance of the condo. the floor has dropped approximately 1 inch where the laundry room and bathroom walls intersect.

There is also a slope in the laundry room about 4 feet in length in the area. I attached a picture of this also:

With the stairs right there and also the framing over the entrance my guess is that the framing in this area is orientated in different directions. The framing over the entrance is not cantilevered as the backspan is only about 4 feet (until the stairs start) and the cantilever is 42 inches. Here is what the exterior in that area looks like below the foyer:

With the laundry room and bathroom in this vicinity the joists may have been notched or cut for piping, but I couldn't verify this as I didn't have access. I also could not see the drywall below this area as it was part of another residential unit that we didn't have access to. We tried but no one has answered on several occasions. If they drywall was cracked or water stained that would indicate water damage and/or sagging due to overloading. this condition could have been going on for a long time as well, every since it was built in 1991.

There was also some drywall cracking near the top of the window at an exterior wall in this area:

I feel like it's safe and there is no life safety issues, but the floor should be opened up in a small area to make sure there is no water damage or notches in the floor joists. any other thoughts?

Thanks,

 

[KootK]

Do you have any evidence of the joists not being cantilevered other than the short back span? That actually sounds like a plausible explanation.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[mfstructural]

I included a floor plan showing the area. I don't it's a cantilever because the part of the joist that would be acting as the backspan is sloping downwards not upwards. the portion of the joists that are acting as cantilever are flat. however, the crack over the window is on the wall supported by the edge of the cantilever (if it is a cantilever).

 

[dhengr]

Mfstructural:
You have to study (and know) the framing system in this area of the bldg., all levels, and guessing doesn’t do much good. We certainly can’t see it form here, and your description doesn’t help much either. I’ll bet there is a fair jamb loading btwn. the bathroom and the laundry room and that this column load, and the floor system immediately around it, are not properly supported from below.

 

[Ron]

Yes, do some destructive observation of the floor framing conditions. You can do so without a lot of effort, but it needs to be done.

 

[XR250]

Unlikely to be a safety issue. Measure the floor thickness at the stairs to get an idea if floor trusses were used. Sometimes these issues are caused by the builder stacking a bunch of sheetrock in one area of the trusses during construction. Could also be water damage as has been suggested. If it has a trussed roof then that takes those loads out of the equation.
Will ultimately have to demo to determine the issue but the seller may not want to go thru that and may choose to find another buyer who does not care (happens all the time in my area due to the low supply of housing)

 

[EngineeringEric]

It could be anything, it could be a poor member selection. probably not safety but i wouldn't say either way without knowing the cause.

good language: recommend to monitor for further movement

 

[KootK]

If it has a trussed roof then that takes those loads out of the equation.

I was actually thinking the reverse. Maybe that wall near the problem area is hanging up some trusses or even a girder. If the load is coming down through the all over some wimpy short span floor framing, it could explain why the issue seems to be so localized within the floor plan.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.