Acceptable grade of basement floor

[BN4537]

That is still quite minimal. I would not worry about it. It will not cause any practical difficulties.

I recommend you take your laser around to other buildings you frequent (or even upstairs in your own house) and see how bad the floors are there. You will likely be surprised how far out of level a lot of the floors you normally interact with are.

 

[jar546]

Thanks to everyone for your feedback. I obtained a self-leveling laser level. When I measure from one side to the other, starting where the flooring meets the shower pan, I see the laser striking the tape measure 1 5/8 inch. Where the laser rests on the opposite side, I see 2 inches. The distance is 104 inches.

So that's 0.38 inches across 8.67 feet, which is higher than the 0.25 inches across 10 feet previously cited, although I understand that does not necessarily apply. I do not know if that's the highest point on the floor.

Thoughts?

I don't see an issue.

 

[ICE]

My laser level is a bowling ball. Not to denigrate your concerns however, there will never be a mountain where there is a mole hill.

It has been shown that when a floor is out of level or a wall is out of plumb, there can be a feeling of unease that is subliminal unless the situation is noticeable to the naked eye. As an inspector, I have encountered the bowling ball on the roll and I was thwarted by management in my attempt to force a correction.

The bottom line is that without the level or laser transit, you would not know that the floor is not perfectly level. 3/8" in eight feet is not perfect but I suspect that you didn't pay for perfect.

 

[wwhitney]

Thanks to everyone for your feedback. I obtained a self-leveling laser level. When I measure from one side to the other, starting where the flooring meets the shower pan, I see the laser striking the tape measure 1 5/8 inch. Where the laser rests on the opposite side, I see 2 inches. The distance is 104 inches.

So out of level by less than 1/2%, i.e. not much at all.

So that's 0.38 inches across 8.67 feet, which is higher than the 0.25 inches across 10 feet previously cited

That was a criterion for flatness, not levelness. Flatness is not directly measurable with a laser level(*), you'd need a 8' or 10' straight edge, which you put down on the surface and look for the largest gap under the straightedge, and then measure the gap size.

Cheers, Wayne

(*) You can try to use your laser level as a straight edge by locking out the auto-leveling feature. Then if you know the two highest spots, you can shim the laser line to a constant offset from those two spots, say 2". If you then verify that nowhere else is less than 2" from the line, and find the spot that is farthest from the laser line, the discrepancy is the out-of-flatness. If you do find another spot less than 2" from the line, now you have to adjust your laser line "straight edge" accordingly.

 

[Yankee Chronicler]

The building code (the Residential Code, in this case) doesn't establish criteria for either flatness or levelness of concrete slabs on grade. As has been commented. this is usually written into the project specifications, put on the construction plans, or written into the contract. If it's not written in any of those places, there are no standards and it's up to the concrete contractor to provide the best work he can.

As was stated in response #12, this is not a code issue, it is a civil issue.