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Discussion Starter · #1 ·
Whenever walking around in these two rooms the floors seems to shake and give slightly which causes furniture to rattle and move, it's not to the point of failure but is still worrying since everything in the room shakes, it's rather annoying.

Can this possibly just be the floorboards themselves? Or are you guys thinking it's the main joists? How can it be remedied?

Thanks!
 

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Going to need a whole lot more info about the home to even guess.
Single story?
Slab, crawl space, or basement?
How old is the home?
What type, size and span are the floor joist?
What type and thickness is the subfloor?
Joist been inspected for moisture, fungus, insect damage?
 

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Discussion Starter · #3 ·
Going to need a whole lot more info about the home to even guess.
Single story?
Slab, crawl space, or basement?
How old is the home?
What type, size and span are the floor joist?
What type and thickness is the subfloor?
Joist been inspected for moisture, fungus, insect damage?
It is a three story row house built in 1900. This floor is in between the first and second floors. The sub floor is individual boards nailed down with no space between them, unfortunately I'm unable to remove the floor to get a look at the joists just yet, but will be doing so within the next month. In other words though, I know this 'give' isn't normal. I understand some houses are built with beams that can span greater lengths without support, but result in play when walking on them? I can tell you that's not the case here, since everything is wood, and it's all original from 1900. Based on what I've seen in the house otherwise my best estimate for the span would be 12-14". Unfortunately that's all I know as of now, thanks for any help you can offer
 

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My best guess from working on 100 plus year old house for about 15 years is you have balloon framing (Google it), only 2 X 8 joist that will be over spanned.
1 X 6's used as a subfloor with no screws just nails.
Only way to really fix it is with some major demo.
One we did would sag 1" in the middle just from my biggest guy standing in the middle of the room above.
An old plaster walled, ballooned framed house almost never has any or at least minimal insulation, old wiring, not even close to code spacing for the outlets so we tore out the old plaster on the walls and ceiling, rewired, added 2 X 10 LVL's to the floor joist, insulated and sheetrocked the walls.
 

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Discussion Starter · #5 ·
My best guess from working on 100 plus year old house for about 15 years is you have balloon framing (Google it), only 2 X 8 joist that will be over spanned.
1 X 6's used as a subfloor with no screws just nails.
Only way to really fix it is with some major demo.
One we did would sag 1" in the middle just from my biggest guy standing in the middle of the room above.
An old plaster walled, ballooned framed house almost never has any or at least minimal insulation, old wiring, not even close to code spacing for the outlets so we tore out the old plaster on the walls and ceiling, rewired, added 2 X 10 LVL's to the floor joist, insulated and sheetrocked the walls.
This was my best guess as well, I was hoping it may just be the flooring but it definitely feels like a framing issue. How difficult is it to sister the joists? I planned on installing new walls (and wiring) as well as a new subfloor anyway, so the demo work is not a question. There shouldn't be any plumbing to worry about as there are no fixtures in the front of the house (other than a radiator but I suspect those pipes to run vertically and not through the joists). There's no ceiling fixtures below either so I doubt any wiring is run through either. Obviously I understand the presence of either of those two would complicate matters. Will sistering the joists be enough?
 

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If you have that option that's a good thing.
Your going to likely find there's no fire blocking in the wall, little or no insulation in the walls, huge empty voids behind the window trim, not near enough outlets to meet code, way to many outlets on one circuit.
Going to use window A/C's then use a new 20 amp. breaker 12-2 wire on it's own circuit.
How high are the ceilings?
What we did, right or wrong but it worked is notched the wall studs to install a recessed ledger, then used 1-3/4 X 10 LVL's that where glued and through bolted to the old floor joist.
Here's how we proved it worked, before we did anything I had the 300 Lb. electrition just go in the middle of the room and stand, the floor sagged 1-1/2.
When we got done and rechecked it the tape measure never changed.
 

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Discussion Starter · #7 ·
If you have that option that's a good thing.
Your going to likely find there's no fire blocking in the wall, little or no insulation in the walls, huge empty voids behind the window trim, not near enough outlets to meet code, way to many outlets on one circuit.
Going to use window A/C's then use a new 20 amp. breaker 12-2 wire on it's own circuit.
How high are the ceilings?
What we did, right or wrong but it worked is notched the wall studs to install a recessed ledger, then used 1-3/4 X 10 LVL's that where glued and through bolted to the old floor joist.
Here's how we proved it worked, before we did anything I had the 300 Lb. electrition just go in the middle of the room and stand, the floor sagged 1-1/2.
When we got done and rechecked it the tape measure never changed.
Oh this house is a real treat. For some reason someone updated the original wiring from knob/tube but kept the entire third and second floors and half of the ground floor on one circuit! That's outlets, appliances, and lighting. Definitely going 20amp dedicated appliance circuits and all new everything basically. I guess I won't know what I have until I dig it apart. Both the frontmost and backmost bedrooms do this, unsure if there's visible or measurable sag, but it definitely feels like I'm walking on something unstable, and I'm around 200 lbs so it's not like being over load is the issue.

I am trying to figure out what to do with the in place wiring if it's in the middle of the run (which it most likely is). Should cut out the room and splice in new romex between the cut and have blank covers over the j-boxes?
 

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You can not legally add onto ungrounded circuits.
Cracks me up when I have customers buying old homes that have " history", always want to fix it up, I can buy it cheap.
My first question is can you afford a bare minimum of $100,000 to fix it up.
It's going to have old steel supply lines that need to go.
All wiring will need to be replaced from the pole out.
 
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