Thread: Residental Walks and Dranage

I have always had the impression that an outward slope was required on sidewalks (away from the house), that were next to a house to facilitate drainage of water, especially from downspouts.

It this true and where in the codes would this be addressed?

Supposedly its in the Code somewhere but I've never bothered to look it up. All you need to do is show the client the wall damage from the inward sloping service walk and that pretty much takes care of it.
If someone has actually looked it up and has it that would be great.

I don't know of any national code, but around here, because of our very expansive water activated soils; positive drainage around foundations is mandatory and common sense.

Law 18.

from the 2006 IRC (bold added)
R401.3 Drainage. Surface drainage shall be diverted to a
storm sewer conveyance or other approved point of collection
so as to not create a hazard. Lots shall be graded to drain surface
water away from foundation walls. The grade shall fall a minimumof
6 inches (152 mm)within the first 10 feet (3048 mm).
Exception: Where lot lines, walls, slopes or other physical
barriers prohibit 6 inches (152 mm) of fall within 10 feet
(3048 mm), the final grade shall slope away from the foundation
at a minimum slope of 5 percent and the water shall
be directed to drains or swales to ensure drainage away from
the structure.Swales shall be sloped a minimum of 2 percent
when located within 10 feet (3048 mm) of the building
foundation. Impervious surfaces within 10 feet (3048 mm)
of the building foundation shall be sloped a minimum of 2
percent away from the building.

Rich,

From you, from the 2010 Florida Building Code, Residential:
- R401.3 Drainage.
- - Surface drainage shall be diverted to a storm sewer conveyance or other approved point of collection that does not create a hazard. Lots shall be graded to drain surface water away from foundation walls. The grade shall fall a minimum of 6 inches (152 mm) within the first 10 feet (3048 mm).
- - - Exception: Where lot lines, walls, slopes or other physical barriers prohibit 6 inches (152 mm) of fall within 10 feet (3048 mm), drains or swales shall be constructed to ensure drainage away from the structure. Impervious surfaces within 10 feet (3048 mm) of the building foundation shall be sloped a minimum of 2 percent away from the building.

"Impervious surfaces within 10 feet (3048 mm) of the building foundation shall be sloped a minimum of 2 percent away from the building."

That allows for concrete walkways, stoops, patios, landing, etc., to slope within the requirements of slopes permitted for landings.

It's not a coincidence that most government building and infrastructure construction specifications require a minimum surface slope of 1/4" per foot, for streets, roadways and walking facilities. In round numbers, 1/4" = 0.0208', or darn close to 2%. In the olden days, when slide rules were the common engineering office tool, it used to be 1.5% minimum slope.

Originally Posted by BridgeMan

It's not a coincidence that most government building and infrastructure construction specifications require a minimum surface slope of 1/4" per foot, for streets, roadways and walking facilities. In round numbers, 1/4" = 0.0208', or darn close to 2%. In the olden days, when slide rules were the common engineering office tool, it used to be 1.5% minimum slope.

2% = 1/50

1/4" per foot = 1/48

Like you said "darn close".

Engineers are used to thinking in decimals ... contractors are used to thinking in inches/foot

Originally Posted by BridgeMan

..... In the olden days, when slide rules were the common engineering office tool, it used to be 1.5% minimum slope.

I still have mine somewhere!!!

Originally Posted by BridgeMan

It's not a coincidence that most government building and infrastructure construction specifications require a minimum surface slope of 1/4" per foot, for streets, roadways and walking facilities. In round numbers, 1/4" = 0.0208', or darn close to 2%. In the olden days, when slide rules were the common engineering office tool, it used to be 1.5% minimum slope.

Which makes an interesting issue. The landing must be level. The sidewalk, if parallel to the house must be sloped 1/4" to the foot away from the house.

So, for a 36" sidewalk that is terminated at a landing, and parallel to the house, would be level at the landing at the side that is adjacent to the house, and 3/4" lower at the side further from the house. Would the "Trip hazard" enter into this situation at the landing?

I know the common sense aproach would be that the first slab would start level with the landing and end with a slope, but the issue interests me.

Originally Posted by Rich Goeken

Which makes an interesting issue. The landing must be level.

"Level" means 1/4" per foot or less slope.

The sidewalk, if parallel to the house must be sloped 1/4" to the foot away from the house.

So, for a 36" sidewalk that is terminated at a landing, and parallel to the house, would be level at the landing at the side that is adjacent to the house, and 3/4" lower at the side further from the house. Would the "Trip hazard" enter into this situation at the landing?

Not is both matched and both were at 1/4" per foot slope.

Originally Posted by Jerry Peck

"Level" means 1/4" per foot or less slope.

Not is both matched and both were at 1/4" per foot slope.

Would this include a landing under a roof, but open on two sides?

Originally Posted by Rich Goeken

Would this include a landing under a roof, but open on two sides?

Yes, even an interior landing has the same "level" requirements and allowances ... although I doubt you will find an interior landing that far off level.

Originally Posted by Jerry Peck

Yes, even an interior landing has the same "level" requirements and allowances ... although I doubt you will find an interior landing that far off level.

Except in Colorado........

Originally Posted by Rich Goeken

Which makes an interesting issue. The landing must be level.

The landing is not required to be level.
It can have a .25 in 12 slope on it also.

"The landing shall be permitted to have a slope not to exceed 0.25 unit verticalin 12 units horizontal (2-percent)."

I sent a note into the builder saying that the sidewalk in the front of the house did not meet the Florida building code requirements for drainage, and that I wanted it replaced from the driveway to the landing.

This should be interesting. Thanks for the code reference.