My kitchen floor is dished. The middle of one interior wall was set on a pier without sufficient compaction. The settling was rapid, as the upper cabinets are set level, while the floor is 2 inches lower in the middle of one wall.
Imagine child's saucer sled writ large. It's 24 feet across and 2 inches deep. A support wall runs along the 24 foot dimension across the middle of the dish. So I have a dining room and a kitchen each dished toward the middle of one of the 24 foot walls.
The floor is smooth. If I use a 4 foot level at no point do I get a 1/8" gap. But it is not flat.
A 2" dish over 24 feet corresponds to a .35" sag on 10 feet or a .06" (1/16) on 4 feet.
Can I lay laminate on this?
Please do not say, "fix the house first" to do so would require shortening the support wall. Yes. The 2nd level floor is flat. Go figure.
That the upper cabinets on the lower wall are straight, makes me think that the bulk of the settling took very early, perhaps as early as during the completion of the decking on the bottom floor. Given the geometry for this to NOT be a support wall, then the floor above is cantilevered out 12 feet. (Half loft ceiling.) –