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need real expertise asap please: Floor Leveling Problems

3379 Views 29 Replies 8 Participants Last post by  jagans
Was laying new laminate flooring. SIMPLE!
...except the floor is not flat and there was a .75" dip in some spots.

So i called contractoes and they lookes and said use selfleveling concrete. SIMPLE.

so i puf 12 bags of it doqn and it is level. GREAT

Then i come back the next day and it is not flat again. So, like an idiot i lut more down and assume i screwed up my snap lines or something.

I put down another several bags.

Next day, there are still low spots again!

Call more contractors for estimates in case joists of floor are sagging. They look in at the joists and first 4 contractors say to just put more leveler on, joists are ok. Last contractor comes and shows me the cracked joist and says i need to fix it but he is busy.

So i rip down the dropceiling, electrical, and ductwork and see that there are 5 cracking joists and they are all bowed and rolling over.

Area is about 12'x13'. Is the ceiling of a bedroom and the floor of dining room.

My questions are this:

Do joists need hangers on the ends where they meet the skin of the house? None of mine have them. Is this why they have bowed and rolled over about the horizontal axis?
Anything i can do about this other than sister joists?

I have to fur out all the joists first; using scrap osb and ply. Should i screw them on or nail? Does it matter for these?

For the sister joists themselves i am using liquid nails and carriage bolts in a zig zag pattern every 15" or so and a few scresw for goodmeasure. This ok?

Big Question: i have a few large humps (1/8") in the newly leveled cement. Is there a good way to sand these large areas down? All i can think of is an angle grinder....which is not all :)

BIGGEST QUESTION: should i jack up all the joists and ruin the leveler i have already applied on the floor upstairs or leave the joists sagged and sister them just like that? If i a jack up and it cracks upstairs floor, can i just poor more leveler in the cracks or is that junk idea?

Thanks! A LOT!
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Lets me star by indicating that I am not a pro so if you want to stop reading further feel free. I waited for a pro to respond before writing my post. Also keep in mind that for every DIY issue there may be more than one way to go about solving a problem.
Here is my take. You are right about sistering additional joists. That is what I would do. I would also jack up the sagging floor so it is level. If you are really lucky the floor leveling compond will crack and can be removed by hitting it with a sledge and using a pneumatic chisel. After all if you level the subfloor you won't need the leveling compound anyway. I haven't worked with floor leveler so I can't predict much except that you can expect it to crack. If you want to keep the leveling compound you could rent a device that looks like a floor buffer but with diamond abrasive. Regarding the use of hangers, if the joists rest on a sill plate then the new ones would not need hangers. And since you are sistering, you probably would not need them anyway. If you do go for hangers (should not have negative ramifications should you go that route even though not necessary; think wearing a belt with suspenders) get hangers that will hold a double joist so the sister will be in direct contact
with the faulty joist. I use screws and adhesive to join the joists but nails can be used as well.
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Do you think there would be a problem with leaving the floor as-is and just sistering the joists with the leveler on top of it witjout jacking it up?

What drawbacks are there?
If I undertsand correctly there is a maximum 3/4 inch dip. Then the sistered joist would have to be 3/4 inch below the faulty joist. Other joists would vary according to the deflection of the subfloor. But using 3/4 inch as an example you would need to either take 3/4 inch off the sister using a circular saw or notch the sister on both ends so that it runs under the subfloor w/o lifting it. Yes, it can be done. And it would involve less work. You would be strengthening the floor. Would it be a bear to remove the self leveling compound? Probably. Would not removing it work? Yes, provided the sisters are alterred. If you could redo the fix, as you know the self leveling would not have been needed. But that's water under the bridge and I probably would have tackled this the same way you did.
Maybe a pro will see things differently. Hang on for another view.
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Also not a pro, but if my floor was sagging and I was going to be repairing joists, I would go ahead and fix it properly, by jacking up the floor. If you don't then you'll be stuck with any out-of-plumb / out-of-level floor, walls, etc in other rooms.

How bad are these joists split? It sounds like they may have been undersized in the first place. In that case, you might want to sister a new one on both side of each joist. As Bradeno mentioned - joist hangers were not required in older construction, however, there should have been cross-bracing between them, to prevent them from trying to twist /roll over.
It occurred to me that my responses might appear conflicting. Let me explain. If you want to invest time and effort jacking and removing the self leveler , that is the route a perfectionist would take. Probably that is the way Mike Holmes with deep pockets and lots of manpower would handle the problem. However, I am not certain how much effort you would need to exert or if you are up to it. The other alternative is workable and easier but it is a compromise solution.
I agree with Seattle2K. His response makes sense.

1. It sounds like your floor is in failure, be careful. Once a joist rolls, its all over.

2. How far on center, what is the species of your joists, what size are your joists and what span are they carrying?

3. What is supporting the ends of your joists?
A picture is worth a thousand words. Do you have any?
Definitely be careful. Putting a few posts temorarily under the faulty joists would not be a bad idea. I understand that the floor hasn't given way so the chance that it will is slim. But what I am suggesting is cheap insurance against what could be an unhappy ending.
Also i already furred out the joistst to match the plywood on the ends so taking a picture wont really show the cracls or cupping anymore. Joists appear to be 16" centers.
Also i already furred out the joistst to match the plywood on the ends so taking a picture wont really show the cracls or cupping anymore.
The topic of joist settlement/cracking has been discussed repeatedly on this forum over the past few years, I suggest you read some of the threads to gain additional understanding of the problem. Methods of repair have been discussed repeatedly as well, some of the techniques that have been discussed include sistering, replacement with a larger joist, addition of X bracing, use of cables to strengthen the joist, and conversion of the joists to T joists by use of 2x4 on the bottom of the joist.

Before you decide on a repair strategy, I recommend you analyze the strength and stiffness of the existing joists. This requires accurate measurement of the span of the joists, joist spacing, joist dimensions, and knowledge of the species and grade of the lumber. Once you know this, you can generally look up the strength and stiffness of the joists as related to the actual floor load. Once you have done these computations, you will then be in a good position to evaluate the cause and cure for the apparently sagging of your floor.
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How do i determine what gradse/species of pine it is? I do believe it is pine.
Does anyone know from first hand experience how strongly floor leveler adheres to the subfloor and how much work would be involved in removing it? To me this is just as important in selecting a solution as knowing the species of wood that the joists are made of. I have never used floor leveler.
Floor Leveler

The floor leveler is really the least of your problems right now. Pictures would really help. The species of the failed joists really does not matter at this point, I just wondered if you knew.

I would hold what you have by jacking a strongback under where the joists cracked. Put a 2 x 6 Minimum plate on the floor, and a strongback on top an jack to hold, then break out the leveler with a lump hammer and a bar, A shale bar will help here, so would a well made ice scraper.

Once the leveler is gone you can work on the floor. Send pictures once you have it jacked up, maybe it is not as bad as it sounds.
I think there are bigger problems to deal with. In a 12'x13' room you have 5 cracked joists and some are rolling, sounds to me like you have some structure problems. It could be anything from undersized to movement and you did not help by adding the weight of all the leveler. The first thing I would do is get some support under those beams then remove the leveler. And I would also check the joists in the rest of the entire house. To be honest this may be a little beyond the scope of DIY. You may find this is just an addition that someone did poorly, but you must find out why this happened, and if it is just this one location.

Ok so it isnt an addition; it is part of the original build. I have put about 20 50lb bags of leveler on the floor upstairs over a 10x 15 area.

That help?

What would you guys like pics of since i alread furred them out? I will do so tomorrow when it is light out since I have power off in there.

So the new sister joists are 2x10 douglas fir that i have ripped .75 inches off of to fit the bow in the floor. Over only 12' these should be fine if i sister five of the 16" center joists shouldnt it? Seems like i am doing overkill here doesnt it? The floor was sagged in the middle not on the edges, so i am thinking it probably isnt the foundation, or anything that serious, right? There was on board in the middle that was particularly bad that may have been weak to begin with and a couple had several large split knots. Does this suggests the lumber was bad to begin with?

The original joists are a darker orangey color and from 1970 . What might they be?

Also, a couple of the original joists are shimmed up on the inside end where they connect the the butt end of the other joists with the plywood and are supportes by the loadbearing bathroom wall. Is it normal to shim up joists like this???

Thanks everyone...nice to not feel so alome on this mess!
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I think that what the posters want to see is the condition of the joists and how they are supported especially the extent of the bowing and the extent of the cracks. When you say you furred them out, do you mean you put furring strips perpedicular to the joists? I think you mentioned that this would interfere with the ability of the pics to reveal the problems. Am i correct?
Getting back to the jacking which seems to be the consensus, I have to warn you that there is some risk in this procedure. It really has to be done slowly and I am certain there are other things you need to know as well. Do your research before attempting. Would you consider having a contractor do this for you?
The idea of finding out what caused the problem is a good one because there is a possibility that some other defects need to be addressed to prevent reoccurence. However, unless the other defects are obvious I doubt you will spot them. That brings us to an inspection by an engineer. Understand that his conclusion might be faulty joists (bad lumber) and nothing more. However, that would be good news it would provide peace of mind.
Sometimes a simple project like laying a laminate floor becomes a more complicated job. I think every DIYer has encountered this at least once.
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Furred the lengthwise so the sister joist would lay smooth across the plywood plates on the ends.
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