# outdoor concrete stairs - level or slope?



## jackwashere (May 5, 2010)

I'm building a concrete form for outdoor stairs. Are the treads supposed to be level or slightly sloped? I'm thinking if they're level water might not drain properly. If they're sloped water would drain. However is slightly sloped the right way to go? If so, how much of a slope? 1/4" for 10.5" of tread? My ratio is 7.5 riser to 10.5 tread.


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## TarheelTerp (Jan 6, 2009)

If it ever rains, snows or gets cold enough for ice where you are...
then yes, there should be some slope so that water doesn't pool.

How much slope? 1/8" per foot should be plenty.

hth


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## cleveman (Dec 17, 2011)

I recently did the two-step, and I sloped them at the same slope as the walk leading up to them. This was a bit more than 1/48 or 1/4"/foot, but not much more.

I don't think it is natural to go from a slope to a level surface or vice versa. Plus the drainage factor.

Additionally, it would be more difficult to form them up because I just had one box resting on the walk form, and another box resting on top, all screwed into form stakes. If you start shimming up the steps to make them level, you're going to change your 7 1/4" riser to 8" in a hurry. So if you do want to do this, plan ahead. Otherwise, your 21 3/4" rise for 3 risers will turn into 3 different riser heights.

Make sure you finish them plenty rough as well.


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## jomama45 (Nov 13, 2008)

Always a small amount of pitch on steps, as it makes them easier to climb, as well as obviously more apt to shed water. A 1/4" is plenty, as long as you can hold the height through the pour by keeping the surface relatively flat, which is sometimes harder than it sounds for an amatuer.

Also, depending on the width of the steps, you'll likely want to put a "stiff'back" on the backside of the form to keep it from bowing under pressure.

Make sure to oil the forms well, vibrate/tamp the faces, and don't wait too long to strip them if you plan on finishing the faces.................. :thumbsup:


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## cleveman (Dec 17, 2011)

how long would you wait to strip the forms on a mild day, high of 75 and low of 55? I haven't even considered trying to finish the riser because I wouldn't want to risk this.


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## Bud Cline (Mar 12, 2006)

> how long would you wait to strip the forms on a mild day,


About four to six hours if you intend to do a rub 'n' scrub finish and get rid any form marks.


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## jomama45 (Nov 13, 2008)

cleveman said:


> how long would you wait to strip the forms on a mild day, high of 75 and low of 55? I haven't even considered trying to finish the riser because I wouldn't want to risk this.


It's actually not too serious of a risk if you think through your forms well & make it easy to remove them. If you do cause any damage, it's easily fixed while the concrete is in the plastic state as well.

As for time, it varies greatly depending on mix design, subgrade, etc...., but under the circumstances you're inquiring about, typically about 2-2.5 hours after placing. We always pour them a little stiffer (right when the truck shows up) and vibrate them well so they gain "body" faster, and strip the face when it will hold an edge well. If you pull a form too early, you can simply put it back in place for a little while. And ALWAYS pull the form UP before pulling it away.


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## ddawg16 (Aug 15, 2011)

Actually.....I wouldn't go over 1/16". A 1/8" slope is a lot for a 11" tread. And, even if it's perfectly flat.....the water is still going to drain off unless you have sides. I'm going to assume you have open sides....right? In which case, I think I would go 1/16" negative towards the riser so the water will drain along the riser to the outside. That way, if you did have a little ice, your foot would slid towards the riser and stop vs flying out away from the stairs.....

I would also put a bit of slant in the riser..angle in...gives you a bit more foot room.

I'm becoming an expert on stairs right now....just built them for my 2-story addition. Boy, it's a lot of work.


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## jomama45 (Nov 13, 2008)

I would not suggest EVER pitching treads towards the riser. If you've ever walked a set that has reverse pitch, you know how awkward, and subsequently dangerous, it is to do so. Steps with pitch away from the riser are naturally easier to navigate. You also have to remember, these are concrete steps, and a 1/16" on a non-perfect surface that has broom marks deeper than that won't always work to shed water.


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## Msradell (Sep 1, 2011)

jomama45 said:


> I would not suggest EVER pitching treads towards the riser. If you've ever walked a set that has reverse pitch, you know how awkward, and subsequently dangerous, it is to do so. Steps with pitch away from the riser are naturally easier to navigate. You also have to remember, these are concrete steps, and a 1/16" on a non-perfect surface that has broom marks deeper than that won't always work to shed water.


+1 :thumbsup: I certainly agree, a slope towards the riser is definitely a no no in any place I can even remotely experience icing.


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## Gary in WA (Mar 11, 2009)

If you are under an "I" Code, the IBC and IRC allow maximum 1 in 48 or 2% slope. ¼” (.25) slope divided by 10” (tread) X 100 = 2.5%---- exceeds code. *3/16” (.20) */ 10” X 100 = 2% or just move the decimal point over when using 10” treads (don’t including nosing). http://www.inspectapedia.com/interiors/Stair_Codes.htm

* R311.7.4.3 Profile. *The radius of curvature at the nosing shall be no greater than 9/16 inch (14 mm). A nosing not less than 3/4 inch (19 mm) but not more than 11/4 inches (32 mm) shall be provided on stairways with solid risers. The greatest nosing projection shall not exceed the smallest nosing projection by more than 3/8 inch (9.5 mm) between two stories, including the nosing at the level of floors and landings. Beveling of nosings shall not exceed 1/2 inch (12.7 mm). Risers shall be vertical or sloped under the tread above from the underside of the nosing above at an angle not more than 30 degrees (0.51 rad) from the vertical. Open risers are permitted, provided that the opening between treads does not permit the passage of a 4-inch diameter (102 mm) sphere. 

*Exceptions:*
1. A nosing is not required where the tread depth is a minimum of 11 inches (279 mm). From: http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_3_sec011_par012.htm

*R311.7.6 Stairway walking surface. *The walking surface of treads and landings of stairways shall be sloped no steeper than one unit vertical in 48 inches horizontal (2-percent slope). From: http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_3_sec011_par015.htm

So with a 10-1/2" tread, 3/16" meets minimum code.


Gary


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## jesse09119 (Dec 19, 2011)

Msradell said:


> +1 :thumbsup: I certainly agree, a slope towards the riser is definitely a no no in any place I can even remotely experience icing.


 
absolutely! your run should be 10 inches though thats more of a standard. If you are trying to stretch the stairs in order to reach a given point it is acceptable but keep in mind that the longer the run the shorter the rise should be at 7.5" you should be good with either run. i'd put an eith inch of pitch on exterior stairs.

Typically with interior stairs you'll see a 1/16th of an inch barring a leaky toilet you shouldnt be expecting an water on those so 1/8th is what i suggest. Also if you will be adding balusters pitching the stair toward the front will not contradict the balusters and you will not pick up the pitch as much as if you pitched the stair backwards.


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## jesse09119 (Dec 19, 2011)

GBR in WA said:


> If you are under an "I" Code, the IBC and IRC allow maximum 1 in 48 or 2% slope. ¼” (.25) slope divided by 10” (tread) X 100 = 2.5%---- exceeds code. *3/16” (.20) */ 10” X 100 = 2% or just move the decimal point over when using 10” treads (don’t including nosing). http://www.inspectapedia.com/interiors/Stair_Codes.htm
> 
> *R311.7.4.3 Profile. *The radius of curvature at the nosing shall be no greater than 9/16 inch (14 mm). A nosing not less than 3/4 inch (19 mm) but not more than 11/4 inches (32 mm) shall be provided on stairways with solid risers. The greatest nosing projection shall not exceed the smallest nosing projection by more than 3/8 inch (9.5 mm) between two stories, including the nosing at the level of floors and landings. Beveling of nosings shall not exceed 1/2 inch (12.7 mm). Risers shall be vertical or sloped under the tread above from the underside of the nosing above at an angle not more than 30 degrees (0.51 rad) from the vertical. Open risers are permitted, provided that the opening between treads does not permit the passage of a 4-inch diameter (102 mm) sphere.
> 
> ...


exterior codes are different


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## Gary in WA (Mar 11, 2009)

"exterior codes are different" ------- where might I find that? Other than the IRC wood deck code, I wasn't aware they classed interior vs. exterior.......

Gary


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## jomama45 (Nov 13, 2008)

GBR in WA said:


> "exterior codes are different" ------- where might I find that? Other than the IRC wood deck code, I wasn't aware they classed interior vs. exterior.......
> 
> Gary


With all due respect Gary, I don't forsee an inspector ever checking the steps UNLESS they're considered a main egress to the home. If you want another example, look at the step height max. for egress windows wells, 18"........


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## jesse09119 (Dec 19, 2011)

jomama45 said:


> With all due respect Gary, I don't forsee an inspector ever checking the steps UNLESS they're considered a main egress to the home. If you want another example, look at the step height max. for egress windows wells, 18"........


 
I agree. as far as where to locate the exterior codes Im not 100% sure where to locate those but i do have this link for the interior codes. a visual interpretation we use here all the time.

http://www.stairways.org/SMA-Bookstore


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## Gary in WA (Mar 11, 2009)

I'm aware of the stairs code; been using this for a few years now: http://www.arcways.com/pdfs/IRC2006.pdf just thought you had something new and different. Same one, just comes up quicker.

My code post is just showing the maximum slope allowed that has been field-tested and found to be best. Use it or not, it's out there, better than hear-say... nice to have in case of a law-suit for tripping.

Gary


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