Unlevel floor

NJDAVE · 10-29-2009, 06:40 PM

My first floor sags in the middle by about an inch in some places. The consensus of a few contractors and structural engineers is that the web/truss joists supporting the floor were either undersized or perhaps got wet during construction. In any case, the joists have deflected in the middle.

All of the contractors said their solution would be to put two posts down the center of my finished basement and connect a 12" girder between them. I have balked at this because it would destroy the basement which is a nice open room.

The alternative which no one wants to touch is to tear up the first floor and basement ceiling and then sister the existing joists with level ones. This would require cuttiing the plumbing and electrical that is threaded through the joists. No one I have talked with wants to do this. I am not sure why. Can someone clue me in? Thanks

RTF · 10-29-2009, 08:38 PM

It would be an absolute nightmare to attempt what you have suggested. Take the contractors' advice and install the posts and beam. There is a lot more to it than moving plumbing and electrical, your exterior walls sit on top of your floor system. If you start removing them you will compromise the integrity of your structure.

Joe Carola · 10-30-2009, 12:45 AM

Quote:

Originally Posted by NJDAVE

My first floor sags in the middle by about an inch in some places. The consensus of a few contractors and structural engineers is that the web/truss joists supporting the floor were either undersized or perhaps got wet during construction. In any case, the joists have deflected in the middle.

All of the contractors said their solution would be to put two posts down the center of my finished basement and connect a 12" girder between them. I have balked at this because it would destroy the basement which is a nice open room.

The alternative which no one wants to touch is to tear up the first floor and basement ceiling and then sister the existing joists with level ones. This would require cuttiing the plumbing and electrical that is threaded through the joists. No one I have talked with wants to do this. I am not sure why. Can someone clue me in? Thanks

How old is this house? Is this a house you had built, or did you buy this house from a previous owner?

NJDAVE · 11-04-2009, 01:08 PM

Quote:

Originally Posted by Joe Carola

How old is this house? Is this a house you had built, or did you buy this house from a previous owner?

The house was built in 1986 and I bought it from a previous owner.

Don_P · 11-04-2009, 06:03 PM

It is sometimes possible to run threaded rod from the top at each end of each joist, diagonally down to the middle bottom, jack the floor slightly above level and tighten the rods with turnbuckles, essentially bowstringing each joist. This might be worth talking with the engineer about and seeing if it is possible to preserve the basement space.

An engineer should be able to definitively say whether the joists were undersized if they can see one. If they have seen one and cannot make this determination look for another engineer.

bighammer · 11-05-2009, 06:25 PM

i have done the threaded rod on the roof - Don you are always ontop of your game - good idea and great line about the engineer

NJDAVE · 11-07-2009, 08:39 AM

Thanks Don_P. I will see if I can take this approach.

The engineer proposes developing a report that would include a definitive opinion and recommendation. That would cost about $750. The plan itself would be an additional $750 to $1000.

I may first see if I can find a local contractor who has experience with this approach.

Thanks