# Level Floor Requirements



## willy41 (Mar 29, 2016)

Searching the web looking for information on what constitutes a level floor is frustrating, because in most contexts, "level" is being interpreted as 'ground level' 'mezzanine level', etc.

On this site, I did find a definition of level as being no more that a 1:50 slope, or 2%. But to me, that means if my house is 50 feet wide, one end could be 1 foot higher than the other?

A house for sale in my neighborhood is advertised as a fixer, with "settling issues throughout." So I'm curious as to how "level" the repaired floors would need to be. I'm familiar with using a hose with sight glasses on both ends with markings to determine the relative difference in elevation between two points.

Thanks in advance for your insights.

-glen


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## cda (Mar 29, 2016)

Welcome

Which state are you in??


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## cda (Mar 29, 2016)

If your area has soil problems, would suggest hiring a residential structural person to evaluate the foundation.

Are you also asking about foundation repair company work ???


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## JBI (Mar 29, 2016)

Glen, Welcome to the forum. 'Level' for a home floor is much less than a 2% slope. 2% is appropriate for a cross slope on a sidewalk or H/C Access aisle. cda makes valid points, soils are the first suspect where a building has suffered noticeable settling. More details, including approximate location, would be helpful...


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## Mark K (Mar 30, 2016)

First talk to a geotechnical engineer to understand why the settlement and what needs to be done to prevent further settlement.

I do not believe that code addresses this question thus the question is what slope will you or a potential buyer, if you chose to sell it, find acceptable.


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## mark handler (Mar 30, 2016)

Most sources that I have come across including the American Concrete Institute use the number 1/4" per ten feet.


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## Mark K (Mar 30, 2016)

The ACI 1/4" criteria is concerned with the variation in the plane of the floor and not whether the floor was all at the same elevation.  The 1/4" number referred to was the variation measured when a 10 foot straight edge was laid on the floor.  ACI has moved to other more sophisticated criteria.

Trying to apply the ACI floor flatness criteria to a wood floor would be a frustrating exercise.

There are construction tolerances for concrete and steel construction for new construction.  These do not apply to wood construction and while they might be considered ideals are not required for wood construction.  Be pragmatic.

I am assuming that the ADA criteria for cross slopes does not apply to your project.

An engineer could help you determine whether the settlement has resulted in any structural damage to the superstructure.


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## JBI (Mar 30, 2016)

Mark K - Safe to say that a 5% slope would be excessive for a wood floor in a home though?


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## ADAguy (Mar 30, 2016)

5% would appear funny if you had an aquarium to look at.


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## Builder Bob (Apr 4, 2016)

Look at your state construction defect regulations - they usually have some guidelines for what is acceptable. check with the residential board for your state.


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## ADAguy (Jul 3, 2017)

Try this: National Wood Flooring Association, a defect performance standard.

*Part III *

*Subfloor Flatness and Integrity *



A. Wood subfloors must be flat, clean, dry, structurally sound, free of squeaks and free of protruding fasteners.

1. For installations using mechanical fasteners of 1½” and longer, *the subfloor should be flat to within* *¼” in 10 feet or 3/16” in 6 feet radius.*

2. For glue-down installations and installations using mechanical fasteners of less than 1½”, the subfloor should be flat to within 3/16” in 10 feet or 1/8” in 6 feet radius.



B. If peaks or valleys in the subfloor exceed the tolerances specified above, sand down the high spots and fill the low spots with a leveling compound or other material approved for use under wood flooring. However, it is the builder’s or general contractor’s responsibility to provide the wood-flooring contractor with a subfloor that is within the tolerances listed above.


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## tmurray (Jul 4, 2017)

"Settling issues throughout" = built on unsuitable soil and underpinning is required. 

Unless you are looking to invest serious cash into the fixer upper, I would stay away.


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## ADAguy (Jul 5, 2017)

So Willy 41, have we satisfied your curiosity?


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