Need some advice on leaning subfloor

Hey guys I need some advice.

I have been replacing several of the floors around my home with laminate or hardwood engineered. So far so good then while working in the master bedroom I ran into a snag. The floor has been level everywhere I worked except in this one spot (see links below).

Where the subfloor is on the back of the level it dips down as far as 1/2" by the time it reaches the wall - it dips this way all across the back of this recessed area (which is designed this way for a dresser). You can see from the pics that it is level at the last floor joist where the board seam is but drops from there up against the wall.
I'm installing laminate flooring in this room and it will be running parallel to the direction of the level.

imgur: the simple image sharer

imgur: the simple image sharer

 

Welcome to the forums! Floating that area may give you the levelness you need for a flat floor. However, it sunk for a reason and unless that reason is addressed, it will come back to bite you. You can't lay your laminate with that much of an aberration in the subflooring. You can remove the subflooring in that area and build up the joisting to where it is level, then replace the subflooring (preferred method). Just a little more work, but it will be solid.

 

i agree.

can you get to that area from below ?

 

Thanks for the welcome.

I'm going to go under the house today and double check the supports to make sure there is no sign of damage. This master bedroom is on a second floor over a garage. The picture that shows a small portion of the wall actually spans a good half of the house (and is about in the center). The thing that puzzles me is if I go downstairs and scan inside for any signs of cracks I do not see any - same for the garage area. My thought here is that if it as sunk 1/2" I should have some serious cracking going on around my molding and sheetrock.

The other thing that has crossed my mind is that it might be possible the builder just screwed up. Its hard to believe they were off this much but since we've been doing some remodeling we have found all kinds of stuff that they have either done wrong or it appears they took shortcuts.

As for building up the joist - what would be your suggestion as to how to do this?
Another concern I have is the floor joist location. I know one is about the center of the level but where the next one hits (the one that is off) is going to be tricky. It could be right dead center under that wall or slightly under the other side of it (in another room) - which creates a whole other issue since I just put floor down in there and did not notice any problems with the floor being level.

 

you would "sister" boards to the joists. but really, you have to "see" what you are dealing with under there. before you know what you will have to do. so you either have to see from below. or open up the floor and have a look.

 

I can't actually get to the room below this to get 'up' but I just went ahead and cut a section out to try and see what I could see.

I cut the hole pretty close to the floor joist and dropped in a measuring tape. From there I extended the tape to the next floor joist (see the pics below). I am measuring what looks like 23" from from one joist to another. They could actually be 24" and I may just be hitting the edge of the other ibeam.





I'm not an engineering expert could this be what is causing my bow problem? Lack of support? If so it would sort of make sense I had checked again to see if the floor was level in the adjacent room and it is dead on but then again it would be since the other joist is somewhere on the other side.

 

OK, put your carpenter hat on. The contractor installed a wall over subflooring only without the benefit of proper support. Placing perpendicular supports to that joist to the one past the wall would be the ideal situation, but jacking up the wall would really be helpful.
Are these dimension lumber joists, or engineered trusses?

 

:forgot to add:

I checked the crawlspace earlier and did not find anything to note. Just a frog and a couple critters. No signs of anything unusual however the only thing I can tell from down there is the ibeams of the first floor. All of them seamed fine and the floor/wall area in that area seemed fine.

condo-owner: as for your suggestion to "sister" boards to joints. I understand what you mean. A friend helped me do that in another room when we took out a section in the middle of the room. In that case we had access to joists on all four sides.

However, in this case I can only get to the one beam unless I tear out a wall which isn't practical. The troublesome wall is sitting on OSB between me and the other beam.

 

They are Engineered trusses.

curse the forum limits on posting

 

One more question. Is the floor on the other side of this wall "finished"? If so, is it hardwood, carpet, etc.? If carpet, it can be pulled back, the subflooring exposed to the next joist and new perpendicular joisting installed giving you access to both parallel joists.

 

The wall on the other side is a room that we just "re-finished". We removed all carpet and replaced it with laminate flooring, replacing the trim, etc.