Good morning,
I have an issue with some floor sagging and deflection. Can anyone tell me if they have experienced the problems I mention below, and if they have advice on the fixes?
Background: I have an older home, built in 1959. The room/floor I am concerned with is just under 14' wide and 19' long. The joists run the 14' length. The room has hardwood flooring, which was sanded and polyurethaned at least once before.
From the basement, the joists are mostly accessible (air ducts and various cabling is in the way). The joists are close to 16" on-center, but are only 7" tall (i.e. a 2x7?). The distance for the supports for the joists is just under 14' wide.
Problem: Stringing a line across the 14' walls, I determined the floor sags over 1/4", mostly in the middle of the room. More importantly, an adult walking across the floor is enough to make the floor shake the room. A good hard jump in the middle can make the china hutch wobble slightly and make waves in the fishtank. I have tried blocking between the joists, but with little improvement.
Proposed Solution: The deflection is more critical to me than the existing sag. What I want to do is sister the joists with glue and bolts. Then, use blocking with screws and glue. I wish to sister three joists, roughly in the middle of the room (spaced about two apart).
Some issues I have so far.
1) Without serious effort to temporarily remove electrical cables and air ducts, I can only get to about five existing joists, which are roughly in the middle of the room.
2) Without the temporary removal of cables/ducts, the sister joists cannot reach the supports. They can get close (about 12'), so they will have to be attached to the center.
3) The sister joists will be ripped to 7" in height, to match the existing joists. I don't wish to add any additional joist height, as the basement is only 7' as it is. I hope to finish it within the next 18 months or so.
So,
1) Considering the dimensions of the existing joists, has anyone tried to do this solution above? Was it successful?
2) Will the proposed solution work?
3) Is there any benefit in only centering the sister joist, or will this not do enough? Is there any harm in this?
4) Is there any reason ripping the sister joist to 7" will not work?
5) Is there any reason sistering only the most-accessible 5 joists won't work, or is the only way to do all the joists under the room?
6) Curiously, is there a standard or requirement of how long/high the joist needs to be for a room of this size?
7) Is two days to finish this proposed project unrealistic?
8) Is the idea of leaving the 1/4" sag alone reasonable? Obviously, I would perfer perfection, but is it normal to have 1/4" over 13', over 50 years?
Thanks in advance,
Dave
I have an issue with some floor sagging and deflection. Can anyone tell me if they have experienced the problems I mention below, and if they have advice on the fixes?
Background: I have an older home, built in 1959. The room/floor I am concerned with is just under 14' wide and 19' long. The joists run the 14' length. The room has hardwood flooring, which was sanded and polyurethaned at least once before.
From the basement, the joists are mostly accessible (air ducts and various cabling is in the way). The joists are close to 16" on-center, but are only 7" tall (i.e. a 2x7?). The distance for the supports for the joists is just under 14' wide.
Problem: Stringing a line across the 14' walls, I determined the floor sags over 1/4", mostly in the middle of the room. More importantly, an adult walking across the floor is enough to make the floor shake the room. A good hard jump in the middle can make the china hutch wobble slightly and make waves in the fishtank. I have tried blocking between the joists, but with little improvement.
Proposed Solution: The deflection is more critical to me than the existing sag. What I want to do is sister the joists with glue and bolts. Then, use blocking with screws and glue. I wish to sister three joists, roughly in the middle of the room (spaced about two apart).
Some issues I have so far.
1) Without serious effort to temporarily remove electrical cables and air ducts, I can only get to about five existing joists, which are roughly in the middle of the room.
2) Without the temporary removal of cables/ducts, the sister joists cannot reach the supports. They can get close (about 12'), so they will have to be attached to the center.
3) The sister joists will be ripped to 7" in height, to match the existing joists. I don't wish to add any additional joist height, as the basement is only 7' as it is. I hope to finish it within the next 18 months or so.
So,
1) Considering the dimensions of the existing joists, has anyone tried to do this solution above? Was it successful?
2) Will the proposed solution work?
3) Is there any benefit in only centering the sister joist, or will this not do enough? Is there any harm in this?
4) Is there any reason ripping the sister joist to 7" will not work?
5) Is there any reason sistering only the most-accessible 5 joists won't work, or is the only way to do all the joists under the room?
6) Curiously, is there a standard or requirement of how long/high the joist needs to be for a room of this size?
7) Is two days to finish this proposed project unrealistic?
8) Is the idea of leaving the 1/4" sag alone reasonable? Obviously, I would perfer perfection, but is it normal to have 1/4" over 13', over 50 years?
Thanks in advance,
Dave