[geekinquisition]

3 rooms of my home have 2"x10" floor joists, 16" oc, 16' span. There are no supports beneath & the floor bounces quite a lot.

Is adding a beam underneath my best option to strengthen the floor?

There is roughly 12" from the bottom of the joists to the ground (in the crawl space) & there is no proper access, just numerous service holes cut into the floor & then later patched. Also, the subfloor (which currently is the only flooring in 2 rooms) is solid wood tongue and groove planks.

I considered pulling up some of the flooring to gain access. However, the house shell was constructed & lath added, etc, prior to the 2 interior walls being added. The walls are nailed to the subfloor, though the subfloor was never nailed to the joists). The walls run parallel to the joists and are placed between 2 joists.

The ceiling is closer to 2"x6", 16" oc, 16' span. I say *closer* because the wood in the attic still has bark on one side of the board(s) & varies from board to board. (Beneath a very thin layer of cellulose insulation is a VERY old layer of straw insulation & beneath that is a layer of soot.)

The ceiling in the rooms below flexes, sometimes A LOT depending upon the weight of the person moving about. The plaster ceilings below have cracked as a result of all the movement.

How do I fix the flex in the ceilings so that I can repair the plaster & not have it re-damaged later?

Thanks.

 

[joecaption]

How do you feel about a complete gut to fix all of this?
A floor and joist being that close to the ground and a sealed up foundation are perfect conditions for termites, powder post beetles, mold and fungus.
With that low a building it's near imposable to do this right without removing the flooring. It can be removed even if the walls where set on top of the flooring with a Toe Kick Saw.
By removing the flooring you would gain access to really see what's going on, fix all the failing joist, pore footings, add a beam and piers to hold it up.
You could also add a proper subfloor and insulation so there would not be any drafts coming up through the flooring.

 

[GBrackins]

is this a one-story or two-story home? are you living in it now, or planning on fixing it up to live in?

 

[geekinquisition]

The house is one story.

If a full gut is required, then that's what I'll do. I'm just hoping there are other options, even if they are more time consuming &/or costly, as we live in the house & don't have alternate housing options. Though I suppose we could always gut the rooms one at a time.

 

[geekinquisition]

I'm curious about the mention of cutting away the flooring with a toe kick saw. How would that affect the structure, mainly exterior walls & ceiling that are attached to those walls, if we cut away the floor? I ask because that would leave the walls suspended in mid air, being held only by the nails on sides & top.

 

[joecaption]

It will have no effect on the walls.
There's still going to be subflooring under the wall it's self and it's sitting on the floor joist, so it would be no differant then what you have now.
Subflooring does noting but give you something to walk on.
With the floor out you could add a vaper barrier on the ground, add any foorings, piers and beams needed. Repair any cracked joist, sister new joist that could be wider to prevent bounce and sagging.
Treat for fungus or insect infestation.
Add cross bracing and insulation.

 

[geekinquisition]

So pulling the flooring is the way to go.

Would it be safe to dig out a trench (6 feet from the exterior walls) to allow an adult sized human to access plumbing etc later without having to tear up the floor again? I was thinking if so, we could add an access door through the floor.

What needs to be done about the ceiling, though? Tear out the ceiling & sister or replace all the joists?