Newbie to forum starting to install a new floor; question about leveling

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Skip Helms

Member
Joined
Nov 10, 2018
Messages
15
Location
Asheville, NC
Hello everyone and thanks for looking. I am redoing my kitchen after we had a mildew problem with all the rain this year in Western NC. I understand it's going around. There was a little black mold which was easy to fix but the main problem was the pinkish stuff that had gotten behind the backing boards. So far I've completely removed all of the old cabinets and two layers of linoleum. Under that is 1/2" ply, 3/4" ply and 4/4 red oak on the joists -- 2-1/4" thick altogether. It is all in good shape with no rot.

My problem is that using a laser level I took readings about every two feet and have as much as 1 1/8" difference between the highest and lowest spots along the 28' span but the dips are more pronounced along the width.

This is a 65 year old house and the basement has been jacked many times over the years for sags. As you'd expect, the lower spots are away from the foundation. The lowest is under a load-bearing wall and I'm slowly cranking a new jack up right now but I am running out of places to brace. All of the joists are in good shape. We've been here 18 years and I don't think it has settled much more over that time.

My idea was to use vinyl plank flooring but the floor as it sits seems to be out of spec for that unless I do some serious leveling. I've wondered about self-leveling compounds, laying up shingles or even ripping up the top layer of ply. I'm not worried about the level of the kitchen vs other rooms leading in and the ceiling is 8'3".

If anyone has some ideas on how to go about reaching an acceptable level of flat, I'm all ears and thanks for considering my situation. Also, if the moderator wants to move this to a more specific sub-forum, that's great too. Cheers and good luck with your projects, sh

PS, FWIW, my basement is a full wood shop with all the equipment I'm using for the new cabinets. I haven't done a lot of remodeling flooring but I've built houses from slab to shingles and am generally handy and own lots of tools most newcomers might not have or have used. sh
 
"My problem is that using a laser level I took readings about every two feet and have as much as 1 1/8" difference between the highest and lowest spots along the 28' span but the dips are more pronounced along the width."

Is that a gradual change in flatness over the 28 feet? If it's a gradual bow over 28 feet, that's not as bad as high and low places all over.

Self leveling products seek level. If the house has any slope, the self leveling compounds want to go to the lowest point. Regular floor patching compounds can be screeded to make the floor flat right where you want it.
Can you show a layout or sketch of the areas you are planning to do?
I'm assuming that this is not one large room?
 
Thanks highup. The culprit is a joist that was sawn-through for a toilet pipe. I'm going to need to build a plumbers box around it and put a beam under a span of about ten other joists. Almost all of the wires you see are bored through the joists to either side but they just left them hanging there. I'll try to fashion some sort of conduit to clean them up as part of the project.

And yes, stretching a string over the floor had much less variance than the level did so I'm use that to hang the cabinets straight. You have to be careful but an 8' fluorescent bulb is really straight. Rolling one of those around on the floor is a quick way to check for dips too. This will take a while so I'll report back in after I've jacked up another beam. Cheers to all, sh
 

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Thanks Gents. And yup, Ernesto, almost every wire in the house goes from the panel (in that little room) through the hole to everywhere else. The only wires I have to move are the ones I drilled through the joist myself. I'll have to re-rout the sink plumbing, replace the cast iron elbows and move the 2" dishwasher pipe.

Right now my plan is tear everything out and sister the joist. When it's in place, I'll crank up the drooping ends with bottle jacks and bolt it to the new one. Then I'll put a 2x4 I-beam under it and the joists to either side making the room divider shown at the bottom of the frame slightly load bearing. Looks like an all-day miserable job if I'm lucky.

The other basement work is going better. The house is 80 feet long by 30 to 40 feet wide and has three rows of 8x8 cinder-block columns spaced every ten to twelve feet that hold central beams. Those are 2 by 2x10 with 2x4s on the outside that act as the ledge for notched 2x10 joists. Almost the whole house has had new beams of various kinds installed between the rows or columns in a row except where I'm doing it now. Each of the two beams under the kitchen floor are sagging about an inch between the foundation and the first pier. I've been cranking the first of them up gradually with a pair of bottle jacks and cinching it permanent with a mono-post. The first one has nothing above it but floor so I'm averaging a quarter inch a day. Dips in the floor above are already half what they were. The second beam is load bearing so that will be more like an eighth every other day.

One issue is that the 2x4s on the beam are separating from the 2x10s because of the weight. It's not a great picture but the one called Corbel Ledger shows the bottom of the far 2x4 (fourth board) about 5/16" below the two centers. What I'm doing there is gluing the heck out of a 2x8 and screwing it to the bottom of the beam. Then I'm jacking that up until they are as even as they'll get and driving 3/8" x 5-1/2" lag screws into the bundle on 12" centers alternating the side if I can get to it.

The upside is that this is the area with the level problem for installing the new floor. If things go as well as they are going, it should be flat enough without having to do anything to the floor itself.

More when I get it, Thanks, sh
 

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Might use a 4x4. Just looking at that makes me thankful i live on a slab on grade.
 
Love your slow as you go lifting procedure, Skip. Took time to sag, and it takes time to un-sag. Very nice.
 
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I don't see how a 4x4 helps. The left picture shows a cross-section of a central beam midway between two support columns. They are more-or-less flush at the ends.

The 2x4 ledger boards are being driven out of alignment with the central 2x10s by the weight of the joists. The pic on the right shows a 2x10 that I've ripped to fit (these are old school 1 3/4" 2-bys) pushed back flush with a pair of bottle jacks and a metric buttload of liquid nails until the floor above is flat Then I lag screw them into place.

So far it's working. The room with the load bearing wall is next. On one side of that beam the 2x4'is out as much as 3/8" of an inch between the piers. I showed the gap as consistent but these are old boards and straight lines are a thing of the past. If I want consistent contact with the joist and the oak primary flooring I'd like to take out some of that slop. FWIW, I got the cut joist sistered-in today with lots of cast iron pipe demolition and spraying copper lines. Worst day of the project but someone had to do it. sh
 

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Oh, that kind of 4x4! Yes, in the permanently supported spot on the beams above the mono-post I'm using an ancient PT 4x4 that I've cut a little long to go under the four-board bundle. The pictures from the last shot are for the gaps with nothing under them. Some of those 2x4s aren't full length and are butted end-to-end. That's where they are failing the worst. Cheers and thanks again, sh
 

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Hello Gents, Hope you had a great Thanksgiving!

I didn't intend to hijack my own thread for a framing discussion and moderators are welcome to act as they see fit. I got the two central beams under the kitchen straight by lifting them up with bottle jacks and setting them back on mono-posts. I did even (sorta) the sagging 2x4 ledgers and bolted them in place. There was somewhere between 1/2" and 3/4" of sag over a span of 12' -- which I think is pretty good for a 64 year-old house. It was well made.

It has also been remade, we think in the early 1970's. A new load-bearing wall was put between the breakfast nook and the library that is about 14" inside the beam. I've sketched that out in the included diagram. So the joists are still sagging -- again, about 1/2" to 3/4". The new posts brought the floor up about 40% of the way to flat from where it was. To finish the job I've got some thinking to do. Most of the house has had beams added -- one a 6x12 steel I-beam, to bolster the north 2/3's of the house but the kitchen end did not.

The lower graphic shows the issue: I've exaggerated this to make the point. There is a pronounced hump in the library a foot from where the load wall is crushing down on the unsupported joists. Those joists have a little more sag along their 11' run but the main compression happens right where the forces of up and down meet. There is an existing closet between two basement rooms but it is not load-bearing and I've already ripped some if it out to get at the beams. Tearing-out the rest is not a big job.

My concern is if I put the the considered new beam and lally midway on the span, it doesn't really address the ill-considered load-bearing wall. I'm more inclined to put one directly under the wall. If that doesn't bring me into spec, put another mid-span as shown on the lower picture. Other than having to redo some non-code wiring and some 1/2" copper lines, access isn't bad. I'm looking at using LVL if I can find some in the area. If not, 2x10s with the crowns up.

Any thoughts? I appreciate it, sh
 

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Are you thinking of raising/supporting just a single joist that's in line with the two red dots on those main beams in the big image?
I see the two additional supports that you may be planning to add. The one directly under the load bearing wall, in my opinion, ought to span more then just a single joist to be effective. It really ought to span the entire length (in a perfect world)
 
How about one support location an equal distance opposite the load bearing wall?
But I'm thinking about another beam that would support more joists and use 3 support locations instead of one.
 

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Thanks highup. I've got two issues. The red dots are mono-posts I just installed to level the load beams that run the entire length of the house. Those are doubled 2x10s with 2x4 ledger boards on the outside that hold notched joists. In most of the house those have been jacked up as needed over the years by owners before me. This end of the house hasn't had that done. The beams themselves were sagging as much as 3/4" between the foundation and the first row of cinderblock piers and the weight of the joists was pulling the the 2x4's down and away from the 2x10's.

I jacked those up with bottle jacks to bring the 2x4's up to to the level of the 2x10's and glued/bolted them in place after leveling the sag. That worked fairly well. They are old boards and had their own opinions about cooperating but it solved 40/50% of the issue.

Now I have to fix the sag in the joists themselves. They are also sagging as much as 3/4". Most of the rest of the house had a central I-beam installed between the two rows of cinderblock piers years ago but not under the kitchen. The place was also remodeled in (we think) the 1970's and the load-bearing wall between the kitchen and the TV room was moved so it is about 16" (on center) off the beam shown to the left. That's what's giving me the hump since the joists are unsupported. That's where the 2x4 separation was worst as well.

The hump itself is in a room with an original hardwood floor that can stay that way for a while but the other side of that wall is where my first course of new flooring goes in the kitchen and it is, on average, 5/8" lower than under the support beam to the right. What's done is done as far as the wall goes. I can't seen putting in a new beam between the piers because it really doesn't address the up and down pressures in that 2' space.

The basement had been unsuccessfully converted to living space at one point and there is a floating wall/closet area directly under the whole mess including lots of wires and pipes. I could still tear it all out and put a new beam or bearing wall directly under the one above. That might not fix the sag in the middle though. I could put a beam there too. Right now I'm toying with the idea of putting a 2x6 bearing wall with the studs on 16" centers under the joists about 3' from the beam on the left and sistering the joists between them since that's where the deepest sag is -- very simlar to your sketch except not getting fancy with the beam. I am going to see if a local building supplier handles LVL beams first because they may be even easier to put up. Getting the new bearing supports much closer to the wall would mean moving the service panel and that's trouble I don't need.

PIA, for sure but otherwise I've got to build up the breakfast nook floor and hope the 2x4's, which are as old as I am, don't give much more. The plan was to just get the mold out of the kitchen but there's always something. I'm in no hurry either. If I can get away with one set of supports for that bearing wall that's great. If not, it gets two. cheers, sh

PS, the header shown on the right of the new pic is to access the service panel, sh
 

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Be easier to understand if I was there, Skip. One thing you already know is the bends and bows that took 50 years to distort don't straighten up overnight.
 
Thanks highup. I went up 1/8" every other day on the beams -- probably do the same here or even slower since this is under the central wall.

Here's what I've settled on -- very similar to your picture except the beam is a bit further from the topside wall because of the service panel. I tore out the closet this morning so I have free access to everything. What I'll do is put down a floor sill piece of 2x4 PT and a king stud against the block wall. Then I'll hang one of two LVL beams on hurricane ties to the joists. Next I'll screw a second beam to the first and slowly crank them up with three stout bottle jacks. I may also sister every other joist in the three feet between the two beams so the weight of the wall above doesn't crush the wood. When I hit more or less flush on the floor (or as far as I dare), I'll cut the jack studs to fit and pound them in place. There doesn't have to be anything under this so I might just put another 4x4 in the center of the load.

I'll use Liquid Nails and concrete fasteners on the sill and king studs and let that dry a day or two. Hopefully, getting everything else in place will only be another half day -- not counting some plumbing and wiring. The jack studs will come later but I'll put in some temps at the beginning level and shim them up as I pump the bottle jacks -- might just leave them like that.

Something I didn't do with the beam raising will be to Gorilla Glue 3/4 BB plywood post ends on the bottle jack end of the 4x4's. Those will have 1/4" deep Forstner holes to fit the tip of the jack. They dig into the soft wood and I heard an ominous creak just before the end. I'll also tighten some steel hose clamps a couple inches from the base to protect from splitting.

Pics when I get them, thanks, sh
 

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One thought is to put down a glue down vinyl plank. I just put down Shaw 2mm vinyl planks. It’s flexible enough that level subfloors aren’t a problem. Tough to find the glue though. I think I used Robert’ 7200. Came out pretty good.
 

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I'm impressed by your procedures Tom, especially the 1/8 of an inch every other day. Not much you haven't though of.
I just put 5 bags of self leveling concrete in a home that was raised 2 1/2 inches by Terra Firma. One room had issues they could not correct. After they jacked up one end of the house with 16 jacks, some of the doors now shut perfectly, and others don't open without rubbing. Like you have been doing, they move in small increments and look around as they go to be sure they are moving evenly. Unlike yours, this house has a concrete foundation.
 
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