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Discussion Starter · #1 ·
OK, tore out the old stairs. I bought 6 step risers and they were too long. I exchanged them for 5 step risers. They were too short. In looking at the original stairs, the saw cuts tell me they were built-on-site. OK, I have three treated 2X10X10s. I'm needing the formula to measure and cut to get started. The measurement from the bottom of the deck board to the ground is 45 inches. The floor joist, I guess that is what it is, is 2X8. BTW, the old stair risers are in pieces- got that way to get it off the deck. Any help or suggestions or Internet sites are most welcome.
 

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The height from one step should be between 6" and 7". Divide the height from the ground to the deck by 6 1/2" and since you are at 45" that would be 7 steps including the deck with a little less than 6 7/16" from one step to the next.
 

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These may not be the perfect instructors, but there are literally hundreds of calculators and tutorials out there. You also should be familiar with how to use a framing square. Find a tutorial that you like and go with it.


https://inspectapedia.com/roof/Framing_Square_Table_Use.php


https://www.mycarpentry.com/stair-calculator.html


Always measure the rise from the finished floor. Then figure how deep you want the stairs to be to get your run. Emptying into a yard makes the run a bit less critical.


2x10s are not recommended and are marginal at best for stair stringers. 2x12s are minimum, and some codes require 2x 14s (though I've never even seen a 2x14 in standard treated lumber).
 

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Steve, I guess codes are different in different areas of the country. I always have divided by 7.5 to get the number of risers. 45 divided by 7.5 is 6. 45 divided by 6= 7.5 inches. There will be 6 risers at 7 1/2 inches. I was taught that 7 1/2 inches is the most comfortable step.

I agree with Shop_Rat a 2x12 is minimal for stringers.

Had you measured from the top of the finished floor upper, to top of the finished floor lower, (Or ground in this case) you would need to take the thickness of the tread from the bottom riser. But by measuring from the bottom of the upper floor material this will not work using the calculations I made above.

I assume the flooring is 1 inch thick, so that will be 46 inches from finished floor to finished floor. 46 divided by 7.5=6 risers. 46 divided by 6=7.66 which is 7 5/8' heavy or 7 11/16 light. Once you have your stringers cut you will need to take 1 inch off the bottom of the stringer, that is the thickness of the tread material. If you plan to use 2x material for the tread, you will need to take 1 1/2 inch off the bottom of the stringer.

Had you calculated using the measurement from the bottom of the decking to the ground (45") you would have come up with 3/4" too low on your stringer.

It is strange how codes for stairs are different from state to state, but from what I see they are. I thought the states were to go by the national code.
 

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These may not be the perfect instructors, but there are literally hundreds of calculators and tutorials out there. You also should be familiar with how to use a framing square. Find a tutorial that you like and go with it.


https://inspectapedia.com/roof/Framing_Square_Table_Use.php


https://www.mycarpentry.com/stair-calculator.html


Always measure the rise from the finished floor. Then figure how deep you want the stairs to be to get your run. Emptying into a yard makes the run a bit less critical.


2x10s are not recommended and are marginal at best for stair stringers. 2x12s are minimum, and some codes require 2x 14s (though I've never even seen a 2x14 in standard treated lumber).
I just checked the links you provided, I wish I had something like that when I was building stairs, that is really cool.
 

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take the time and read stair building info. then make a side view drawing. draw the step profile, then draw in the stair treads and risers (if using them).


there are two style of stair sets you can design. one critical issue is the deck attachment point. your top stair/tread can actually be even with the deck, or it can be the first step going down. for type 2 the deck needs to have a nice wide band joist or posts to attach to, and are more challenging to attach. style one might have 7 steps, and style 2 will have 6.
 

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Discussion Starter · #7 ·
The old deck steps were 2X10s. We have lived here for over 20 years plus the time when the deck was built so they have lasted a long time. I'm going to look at using the 5 step boards and building a treated wood pad to fill in the space between the steps and the ground. Lots of way to do this project. Thanks for the links. Will review them.
BTW, would love to get rid of the pool- been in it twice in three years but SWMBO wants to keep it for the grandkids.
 

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2x10 stair stringers may have been fine 25 years ago. However, things do change. Front drum brakes were standard on cars for decades until someone realized that they were not really all that safe. Building codes have changed radically over the years as more knowledge is gained concerning material properties, as well as adapting to human life style changes. Reasons are plenty for updating, not the least of which is described like this:

https://www.cbsnews.com/news/americans-weight-gain-since-1980s-startling/

And that's only since the 80s. I am not suggesting that anyone reading this is at issue, but the facts are that many folks are overweight. It may only take one extra large, or maybe two moderately heavy people traveling a set of steps at the same time to snap an under engineered staircase. I broke my neck many years ago due to a broken stair tread. I went up the stairs empty handed just fine, but came back down carrying a joint of 4" rigid conduit (I was a young apprentice electrician)- too much weight for that very same step. I went through the step, hit the ground standing and 50 pounds of steel promptly smacked me down to the earth. I now have an interest in stair construction for some odd reason.

Doing something simply because "that's the way it was" or "we've always done it that way" is just not my mantra. I will always offer a better or safer alternative if I know of one.
 

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