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Bradeno 12-12-2012 01:07 AM

need real expertise asap please: Floor Leveling Problems
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!

retired guy 60 12-12-2012 03:21 PM

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.

Bradeno 12-12-2012 03:28 PM

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?

retired guy 60 12-12-2012 03:54 PM

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.

Seattle2k 12-12-2012 03:55 PM

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.

retired guy 60 12-12-2012 04:17 PM

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.

jagans 12-12-2012 04:20 PM

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?

brockmiera 12-12-2012 04:21 PM

A picture is worth a thousand words. Do you have any?

retired guy 60 12-12-2012 04:33 PM

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.

Bradeno 12-12-2012 04:39 PM

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.

Bradeno 12-12-2012 04:46 PM

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.

Daniel Holzman 12-12-2012 05:09 PM

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.

Bradeno 12-12-2012 05:14 PM

How do i determine what gradse/species of pine it is? I do believe it is pine.

retired guy 60 12-12-2012 05:50 PM

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.

jagans 12-12-2012 06:09 PM

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.

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