Foundation slope 2

[Bagman2524]

Are there any guidelines in any of the building code sor elsewhere that give permissable values for slope on a home foundation? Is 0.5% too high (3" over 48 ft).

 

[concretemasonry]

What type of foundation?

Is this for an existing individual home or for a specification for future construction?

3" in 48 feet is too much from a practical standpoint. For structural, it would be of little consequence.

Dick

 

[UcfSE]

Sloped footing, not stepped? Is the bottom sloped and top flat?

 

[Bagman2524]

residential home. slab on grade. new orleans area. settlement is common. the slope is the top and bottom of the slab. the slope is constant over the 48 ft width of the house.

 

[MiketheEngineer]

I hope the home owners aren't into marbles.....

 

[kslee1000]

I don't think this is a code issue, but two questions to ask:

1. Human comforts wrt slopping slab.
2. Sliding stability, with the potential to have the slab cracked due to uneven loading conditions not considered in the design, against the horizontal forces on the slopped foundation.

If there is any doubt, and if this is an existing house has sinked after the flood, I suggest jacking and new footing shall be considered.

 

[PMR06]

IRC R403.1.5 & IBC 1805.1: Top shall be level, bottom can be sloped 1:10 max.

 

[Bagman2524]

How level is level?
In New Orleans, we've all lost our marbles. Otherwise we wouldn't still be here.

 

[PMR06]

Sorry, I didn't fully read the previous responses. It is the slab on grade that slopes. Is this a recently constructed house, or an existing one that has settled?

You might also try looking at ACI 117 specification for tolerances. Obviously the original house designer intended a level slab (that's zero slope), so one could argue the tolerances set forth in the ACI spec.

 

[Bagman2524]

Interesting article on the subject I've found:

http://www.foundationperformance.org/pastpresentations/Gray_FPAPresPaper_19May04.pdf

 

[JStephen]

If you don't notice the difference elsewhere, you will when you go to put rain gutters on it.

 

[jdonville]

Bagman2524,

Unless the slab is moving, I don't think that it should be messed with. Your link seems to support that conclusion.

Jeff

 

[Bagman2524]

I agree. There are no signs of structural distress in the house.

 

[Bagman2524]

From ACI 117 tolerances vary based on surface finish class:

AA: 1/8" in 10 ft
AX: 3/16" in 10 ft
BX: 5/16" in 10 ft
CX: 1/2" in 10 ft

Anyone know what these classes are?