Slopped floor of new house
newmedia
| Posted in General Questions on
Hello,
I have a question about the slopped floor of my house. Recently I bought a house and I didn’t noticed the slopped floor at the beginning. However I started to notice it after three months. The front side of the house is slightly lower than the back side of the house.
I measured the foundation height and I noticed the front side of foundation wall is lower than the back side of the foundation wall by 1 inch. Is this acceptable? Should I hire someone to take a look at it?
Thank you,
Jin
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Replies
Jin, You might have a settling or expansion problem that is developing. How did you determine the difference between front and back? Laser level? From inside or outside? What sensations or evidence led you to check the foundation? And how far is the distance between front and back walls.? Do you have a mid span beam between front and back walls? If you have a crawl or basement level, are there any cracks in the wall or floor slab?
Sloppy builders are nothing new unfortunately. I have personally witnessed a foundation pour be completed and then entirely removed to be re-poured due to a major screw-up. I also knew of one house that had a foundation so badly done that a marble set down on the floor at one end of the living room would pretty quickly start rolling diagonally across the floor to the low corner. You may have such a house. Or not.
Good concrete people will generally claim the top of their pours to be within a 1/4" and deliver something more like plus or minus 3/8-1/2. The framers win the job of leveling the sillplates to make the deck true and level. This was done with steel shims under the sill plates after the joists and subfloor were all done and before raising walls on my build. Given the spans in my own home, I am not sure I would have any sense of a 1" drop over 36'. If you are seeing 1" across 22' maybe you could feel it when going "downhill". Spilled water on the floor is often the first giveaway for minor tips in old houses.
If you are not experiencing cracks in the drywall at doorways or corners of rooms near the mid-line of the house, it may be true that it is simply built that way. If you are seeing cracks, then settling or expansive soil conditions may be driving the measured difference. I only have experience with crawl space and full basement homes, so if you have a slab built home it may be possible that settling or expansive soil could tip the whole house as a unit like a house boat. The walls would not necessarily crack, but the house might tilt enough to become perceptible.
If the soil is expanding or settling, then this could occur in a number of ways and places. Expansive clay soils are well known and very prevalent around Denver area, mitigation can take several forms. Foundation footings are typically set on undisturbed or "virgin" soil that an engineer has rated for the loads designed. Support pads for columns under a central beam also have to be designed for the loads and soils on site. If any fudging went on during the foundation dig, that might be a source of the issue. If you do live in an area with expansive soils, over-digging and replacement with controlled soils placed under the guidance of a soils engineer that must certify the replacement soil will bear the loads and not up heave.
It is difficult to say what or if you have a problem from your limited description. If the house is very old and was framed with green wood, shrinkage across the floor joist's height might show up this way, though not too likely. If it is very old and has hidden water damage of the sill plate on one side the house, the whole side of the house can settle down. I helped repair a 1820 vintage house with 6x6 sills on a field stone foundation. The east sill was totally mush and that side of the house was quite droopy.
If you can post more information, maybe the group resources here can better advise what kind of advisor you might need to contact. Might be a soil engineer, might be a structural engineer. Hope this gives you some avenues to explore while getting a better handle on conditions around the house.
Hello Roger,
Thank you so much for your kind explanation!!!
So.. this house is a new house. It's built at 2019.
I used a laser level inside my house(at the first floor). I also measured the front/back wall height in my basement too. The wall height difference and floor height difference seems match.
The reason I decided to check the level is the feeling of walking up. Whenever I enter my house i had feeling that it's a slight uphill.
I think the slope start at the mid span beam which separate the front and back of the house. (The bean is at the center.) I think the front left is lower than front right. I think the back half of the house does not have slope.
I see hairline cracks on the foundation walls and floor slab. I don't see any major cracks.
One thing I cannot understand is that front half of the house floors are feeling softer than the back half of the house in all floors. The back half of the house floor feels very solid. However the front half of the house floor feels softer.
I don't see any dry wall cracks on the wall near the mid-line of the house where the mid span beam is located.
Is there a technique accurately measure the slope? I just used my old laser level. Maybe I need to measure the wall height with a self leveling level. Do you have any recommendation?
Thank you,
Jin
Jin,
So is this a basement? Can you see the mid-span beam and its bearing connections? One thought is that the beam wasn't placed flush / at the right level, or one side/corner of the foundation is simply lower.
It might not be bad to get someone in to look at it. Internet advise on these sorts of matters can be tough. More description as to what a 'soft' floor means might help. What's the finish?
As far as measuring slope: A laser level should theoretically give you slope by simply measuring rise and run. use a level (for plumb) and measuring stick combo and shoot off that.
If you're not trusting the accuracy, you could build a water level (essentially a bucket of water with some flexible tubing coming out of it. Cheap to make and quite accurate if you make sure to get air bubbles out and let the water level settle in the tube after moving it.
Thank you so much Tyler!
Who should I hire to take a look at it? Structural engineer?
When I walk on the floor, it's moving up/down more than other part of the floor. The floor joist count might be different in the front part of the house.
I think I will buy a cheap self leveling laser level.
Thank you,
Jin
A structural engineer would probably be great, but mostly I'm thinking a builder/someone knowledgeable and competent in construction should be-able to assess the situation on site.
They can hopefully pinpoint where the 'off-levelness' is sourcing from. It sounds like its the finish height of the foundation wall, so determining if it was poured off-level or has moved is probably what needs assessment. I think pouring off-level is more likely, but I don't have all the needed information (soils location, construction details, etc).
Taking measurements at higher elevations of the structure may help tease out the source (second floor if it has one), but it can be hard if the builder compensated for off level in some areas and not others.
I like the water level for taking blind readings (gauging relative height when the objects are not in sight lines.) It's admittedly a bit of a cumbersome device. If you want to access flatness over a plane, a typical bubble level, as Roger suggests, makes sense. If you can procure a decently straight board, piece of angle, etc, you can skip buying the long expensive level, unless you'll be using it in the future a lot.
Thank you Tyler!
Yes. I don't see cracks on the walls. So the pouring off-level is more likely.
I think I can cut my leftover plywood to get a long straight board.
Thank you,
Jin
You should ask the builder to have a look.
Since you are not seeing any cracks in the drywall we have to assume the foundation has not moved.
You say it is out of level by 1 inch but over what distance once 3 feet would be very bad 1 inch over 50 feet would be imperceptible.
As long as, 1 there are no changing cracks in the concrete walls (take photos of all crack today with rulers measuring the gaps) 2 the floor is not changing and the error is barely perceptible.
I say any cure is likely to be worse than the disease.
It seems likely jacking up the floor would damage a lot of your drain plumbing, finished floors, drywall, doors, trim, cabinets and gutters all were shimmed to be level and will not be after you move the floor.
Walta
Thank you so much Walta!!!
I will go and measure distance of the slope tonight, and I will get back to this forum.
Thank you,
Jin
Walta. It's 15 feet.
I’d be most concerned with growing cracks (creep), which would indicate the structure is still settling. What I usually do to check for this is to mark across a bunch of cracks with a grease pencil. I like to make a few “ends” of cracks too. Try to get cracks in both axes. Come back in a week or month and see if any of those lines are now broken at the cracks. Any broken lines indicates the crack has gotten bigger, and you can see which direction it’s growing too. If the cracks are growing, you might have major problems and will definitely want to have someone check it out.
You can use a laser level to check how far off a floor is at various points. Set the laser level up at the high spot and point it out over the floor. Use a piece of white card stock and hold it against the floor in various spots and check where the laser hits the card. If you mark these spots, you can measure the distance between the marks to know exactly how low various parts of the floor are relative to the high spot where you setup the laser level.
If the cracks are NOT growing, then you probably don’t have any safety issues but rather just have a home that was built with an uneven floor. How you go about leveling a floor like this depends on a lot of things so you’ll probably want to get with the builder. It’s difficult to recommend anything specific without seeing the structure.
Bill
Hello Bill,
Thank you so much!!!
I heard that vertical hairline cracks are fine usually. It that true? I will mark the cracks tonight.
What's acceptable slope in terms of degree? Is there any code for that?
Also, I'm not sure what will the builder say. If he says that's what it is, I don't have not much option, right?
Thank you,
Jin
Big cracks start as small cracks. The important thing you want to know is if your cracks are GROWING or not. A few hairline cracks isn’t generally a problem, but if they are growing, then you DO have a problem. What you are looking for is signs of crack propagation, where those little hairline cracks are gradually become big problem cracks.
I’m not sure about codes for floor flatness. There are some provisions in the code that things have to be done in a “workmanship like manner”, but you’ll find it difficult to make any arguments like that. In my 25+ years in the industry, I have seen inspectors care about “workmanship like manner” exactly once, when electricians set a horizontal run of conduit off of level. The next inspector on the job overruled the first too, so even other inspectors didn’t think that was an issue.
Bill
Hello Bill,
Over the weekend, I marked all the cracks with ruler, and I photographed them.
They are all smaller than 1/16 inch at this point. I will keep monitor them.
Thank you,
Jin
Jin, Thanks for the clarifications of age and other details. All the tips given so far should help you along with determining just how much of a problem you have. My main concern is the fact you can sense the floor slope. Our bodies do an amazing job of sensing very small deviances when walking, but it still cause me to wonder if the real slope is more than just an inch.
I would first suggest a six foot or longer bubble level. They are about $70 for an Empire brand. Self leveling lasers are fine, but taking a lot of interval readings across a floor can be tiring and not as revealing. The long level will reveal humps and hollows in the floor as well as the general slope. Buy a package of wood shims to raise the low end and give you a direct readout of the difference over the six foot length. It may also reveal a hump across the center of the house where the beam is. Just keep sliding the level around in different places at different angles to the front wall line and see what you find. Let us know and see what we can suggest for further investigation.
As to the softness of the floor, maybe you are sensing floor bounce. If the span is not equal on both sides of the beam or if the joist sizes are different, then make a note of what they are and post again. This is all a bit puzzling.
Best of luck.
Yes. a six foot level is a good idea. I already ordered a self leveling laser level. I will try the long level method, if the laser level does not work.
Yes. Regarding the softness of the floor. The joist spacing is different in some section. In some section, it's denser than other normal area by 2. I think it's built that way. The dense sections are around the stair case, etc.
Thank you,
Jin
Morning Jin, I kept puzzling over the softness of the floor comment you made. I had imagined all sorts of unlikely sources when it finally came to me that you might have a "floating floor" material that has been installed too tight to the perimeter of the room. Now that you are living in the house the humidity increase that comes with daily life may have finally worked into the flooring. A subtle buckling of the floor would not necessarily cause any of the individual boards to hump up, but instead cause a huge but very low buckle across the entire floor.
As you walk on it, the floor will squish down to the subfloor making it feel soft. I also think that this may be the reason you feel like you are walking uphill. Our bodies expect to find the next step matching our last, so when we stride across or into a small dip we stumble a little. The small uphill grade of an apron in front of a garage or a long cement walkway reveals itself to our senses by making each progressive step feel a little bit more impact than our minds expect. A buckled floating floor might mimic that unexpected contact with steps going across the room and feel soft as well.
Tyler is right, you can save the cost of the level with a board to check and see if the flooring is bowed upward. Look for the bow perpendicular to the long board direction first. Let us know what you find. It may not be the foundation after all.
Roger. Wow! Your explanation make sense. Once I measure my floor with new self leveling laser level, I will report back.
Thank you,
Jin
The observation that the slope may happen only in the front of the house makes me wonder if this is a cut & fill lot, where the back of the house is on virgin soil and the front is on not fully consolidated fill.
Jin - is this a hillside lot with the back of the house somewhat dug into the hill and the front somewhat elevated?
Hello Peter,
The back side has a slope, but it's not severe. The back side of the house is more into the ground than the front side.
Maybe the demolished old house was sitting at the front side of my new house. I don't know....
Can you elaborate your "cut & fill lot" and "consolidated fill" term?
Thank you so much!
Ok. this is summary of my investigation. It seems house is level on the first floor.
However there are uneven floor level here and there. That made me feel like I'm walking up.
Thank you so much everyone. You guys are great!