Replacing Porch Stairs, Sizing Questions
Happy New Year!
About 50-60 years ago, the original wood stairs to the main porch of my 1895 house were replaced with a concrete grouping from another building.
The concrete stairs are crumbling, the rails are loose, and the whole thing never never fit well anyway. It is an eyesore, and dangerous.
The rest of the porch was rebuilt nicely about 10-12 years ago, and is in nice shape. I just sanded the floor and repainted it this past fall.
This spring, I want to tackle demolition of the concrete eyesore and building of a proper set of wood stairs and railings that fit the space. I have some old pictures that show what the original stairs looked like in the 1930s. 5 steps...
Problem is, today we have codes to adhere to. The porch is 45" high, the total run is 65". I think the max code height per stair is 7.75", max depth is 10".
Before I go designing anything, I want to get an idea what to expect from the building inspectors when I present plans. How do they usually deal with the dimensions above?
Attached picture of the concrete eyesore is a few years ago, when it looked better. It's worse now.
Comments welcome and greatly appreciated!
As always, thanks!
For those who might wonder, here is a photo of the front porch in 1938. The side porch was the same, but wider. The girl in the picture still lives in town. I wish my memory of 40 years ago was as good as hers of 70 years ago!
You could check for local code but what we use is max height is 8" min tread is 10".
The quick and easy is to divide the height by 8 and you would get 5.-- so then divide the height by 6. If you are at 45" divided by 6 = 7.5 risers. 6 risers is 5 treads 65 divided by is
12 3/8 or so.
To measure this you want to come level of the deck and measure straight down to where your stairs will land. Your stairs can land on about 3" of concrete at the edge of the sidewalk, I would go for 11 to 11.5" treads. We usually use 2 treated 2x6, when wet will be 11.25 and will dry with a little gap between the 2x6s.
This on stairs for the IBC or IRC, one of which you are under if in the U.S.; http://www.awc.org/Publications/DCA/DCA6/DCA6-09.pdf
I noticed; windows are different- sizes/location/widths, rough openings are not even close. Old pic has a 2' bump out to a flush wall on the right, yours has a 2' bump on the left to a 45* wall with window, unless yours added/moved the foundation and changed all the front walls; they are different porches.... maybe the house next door.
Thanks as usual for giving me a good idea what they will want me to do due the existing dimensions. I do plan to build a framework of treated 2x6s and 4x4s under the stairs for support, not just the stringers like so many people do.
GBR, thanks for the links to the codes. Yep, different porches. The color photo is of the side porch stairs I want to replace. The black and white photo is of the front porch, to give an idea what the side porch original stairs looked like.
Neil's advice is a good method of figuring out how many risers you will need. Taking 8" as a starting guess then fine tuning it to the exact amount to have all steps the same over the total rise. The next rule of thumb I use is that the rise plus run should be close to 18" as possible. This works out for how human anatomy best climbs and descends stairs. In other words if the rise is 7 the a run of 11 feels right to us or a rise of 9 would want a run of 9 for a steeper stair. Don't confuse the run with the tread width also. The nose of next tread often overhangs the one below. This gives the feel sometimes of not being as steep by allowing toe or heal room.
Thanks for the additional advice. It is very interesting, and one of my concerns. I often use the 15-step back staircase (no handrails) of the house, and it has a rise of 8", and a depth of 8", plus a nose of 1.5". From there it is about 12 more steps across the floor until I am at the edge of the porch. As some of the existing concrete steps are not the same dimensions, I'm constantly aware of the differences.
It will be interesting to see what dimensions get final approval by the inspector.
I've often come out of other old houses and found the newer outside stair dimensions to throw me off. I'm used to hiking, rollerblading and skiing, so I might not be affected as much as other people. Thanks again for pointing this out so clearly.
Your very welcome. I have several text books on stair case design and it's quite interesting to study this. Curved staircases are really complex as the gait in climbing is slightly different leg to leg. With rock climbing our brain expects change and in stairs it expects no change. We can detect very small changes. Just a slight change to an easier climb gives and elegant feel to the steps. Front entry steps are sometime like your old steps that have a slight change in width top to bottom to give the illusion of depth. You are correct the steps you are replacing will look much more appropriate for your home. I love the gingerbread in the old photo. You are lucky to have photos.
Total run = 65
Total rise = 45
X = 18
step run always greater than step rise
Number of vertical steps must equal number of horizontal steps
Number of steps must be an integer
rise| run = X - rise| # of vertical steps| # of horiz steps|
4....... 14.....................11.3..................... 4.6
5....... 13..................... 9.0 .....................5.0
6....... 12..................... 7.5 .....................5.4
7....... 11..................... 6.4..................... 5.9
8....... 10..................... 5.6 .....................6.5
You can tweak the X value and the rise value until you get close to an answer. If there is one.
look at this one
7.4 10.6 6.1 6.1
but nobody can make 6.1 steps.
Then the question becomes, "If you can't have X = 18, do you want to go slightly larger or slightly smaller than 18? Which is preferable?"
So there is always one more riser than steps. If you would build a set with one step you would divide the total rise by 2 so 2 risers 1 step.
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