Slope on Stair Treads and Landings
I received an email today from an individual who's contractor had built an exterior concrete stair for them. Each tread sloped 3/4" down from back to front. I quickly emailed them back to let them know that isn't up to code and in fact is quite dangerous. If those treads get wet or icy it could lead to a bad fall.
The International Building and Residential Codes state "The walking surface of treads and landings of stairways shall be sloped no steeper than one unit vertical in 48 inches horizontal." In a 12" deep tread that's only 1/4" of outslope.
In an interior stair the treads are generally going to be flat but in an exterior application it makes sense to have a small amount of slope for drainage.
Originally posted 2011-05-19 10:41:43.
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