code consideration for replacing carpet on existing stairs?

[Forrest Gon]

My basement staircase looks like this, a flight of stairs, then landing area, then another set of stairs,

Screen Shot 2021-09-20 at 5.26.02 PM.jpg


The whole thing was covered with carpet before, and I am removing the carpet and replacing it with wood treads and mdf risers(retro fit, i leave the old treads and cover them will 3/4 new tread).


There is the problem about the stair riser height, I see the code specifies that risers should not be more than 7 ¾ inches in height and that any variation of risers within a flight of stairs should not be more than ⅜ inch.


The existing landing area has no carpet now and needs to be raised. But it has an awkward height relative to the upper stairs and lower stairs


If I raise the height of landing area so the height between the stairs of the upper staircase match, then the first stair of the bottom staircase will not match the height of the rest of the stairs in the bottom staircase.


On the other hand, if I raise the landing area to make the lower set match, the height for the last step on the upper set will be too short(about half inch less then other ones in the same set)


I don't want to change the existing infrastructure, in this case, can I just go ahead and make one set match?

[Jim Dwight]

Have you already made the treads? If not, what happens if you use thinner material for the treads? I used 3/8 oak one time and made a nosing piece to attach to the softwood tread that was there (after removing it's nosing). I also put similar pre-finished thin flooring in a lake house my ex was selling. I think it was Armstrong. You don't need 3/4 for strength reasons if you are going over 2X treads.

But in terms of code compliance you can do whatever you want in your house if you are working without permits. It can't cause you an issue until you sell the house and probably will not then. I had a staircase in my house that varied almost 3 inches in rise and it was definitely noticable but didn't hurt anybody. 1/2 and inch might occasionally cause somebody to catch themselves but at the end of a staircase you should have a newel post they can grab to avoid falling. Most people won't notice it IMHO. But if you had to pick a point for somebody to stumble, the bottom seems safer than the top to me. They can't fall very far at the bottom.

[Frank Pratt]

3/8 variation in riser height is definitely noticeable even if your not looking for the difference. You will get used to it, but it could be a hazard to someone unfamiliar with the stairs. And I highly doubt that a home inspection would miss that on resale.

[Mel Fulks]

Agree with Frank. 3/8ths can activate a trick knee.

[Steve Rozmiarek]

Short of rebuilding them, your best option is to make the upper stairs match riser height to the landing, and the lower to the floor below. That way as you turn the corner on the landing your mind gets a little reset and the difference isn't as obvious. I think they are actually up to code then too as they are treated as two sets of stairs (depending on which code). It's not ideal, but lots of things are compromises.

[Jim Becker]

I agree with Steve here about how best to handle it and also with Frank in that a home inspection is very unlikely to notice that kind of small deviation and even if it were, it's not a legal thing...it's about whether or not the buyer will accept the finding or not.

[Forrest Gon]

hmmm, the issue is "not" upper and lower stairs have difference riser heights.

No matter what I do, either the last step of the upper stairs OR the first step of the bottom stairs will not be the same height to the rest of the stairs in their same set.

If I make the upper stairs match riser height to the landing. The "first" step of the lower stairs will be half inch higher than the rest of the bottom stairs, and vice versa.

Short of rebuilding them, your best option is to make the upper stairs match riser height to the landing, and the lower to the floor below. That way as you turn the corner on the landing your mind gets a little reset and the difference isn't as obvious. I think they are actually up to code then too as they are treated as two sets of stairs (depending on which code). It's not ideal, but lots of things are compromises.

[Jim Dwight]

What about removing the surface of the platform to change it's height? Not easy but would involve the least de-construction.

[Bill McNiel]

I have been faced with this issue more than once.

First and foremost; the code requirement is a valid concern, please do not ignore it. You may adapt to a riser difference over time but someone else won't and there is the very real prospect of a serious injury or even death from falling down multiple stairs. This is a case of doing the right thing as opposed to what you think you may get away with.

My approach would be to determine the common rise and then solve for that by removing the existing treads and then modifying the existing stair stringers (probably three). If increasing the rise height fur with plywood strips, if reducing the rise use a muti tool to cut the stringers from the side. The whole process, including calculations and layout should be done in less than a day. It would be best if the rise were consistent for the full run but having the runs above and below the landing mildly different is a viable alternative.

[Forrest Gon]

oh boy, i might just put back the old carpet ....

[ed morini]

Initially, I would ask when the stairs/house were constructed as that establishes the building code regulations for the stairs. With that base line you can determine compliance, not by the current code.
I can’t recall when the 3/8” variance was adopted but a lot of older homes were built without that requirement.
The only time the new code would be in play would be if you were to revamp the staircase, remove replace the treads. Treads being a structural part have their own code specifications. The riser height variation would be addressed by removing or adding to each treads riser so the run of stairs will be compliant. Using thinner threads could lead to problems if excessive weight caused a failure.
You can leave them as they are or bite the bullet and fix them…your choice
As a former building inspector, I would have to say you should get a permit to alter the stairs but as a practice most stair repair like this is done without one. Since it’s inclusion in the code the 3/8 rule, I have always checked for compliance once on the rough and again for the certificate of occupancy

Ed

[Steve Rozmiarek]

hmmm, the issue is "not" upper and lower stairs have difference riser heights.

No matter what I do, either the last step of the upper stairs OR the first step of the bottom stairs will not be the same height to the rest of the stairs in their same set.

If I make the upper stairs match riser height to the landing. The "first" step of the lower stairs will be half inch higher than the rest of the bottom stairs, and vice versa.

Ahh, gotcha. Can you get to the stringers? If they are framer built stairs you may be able to adjust the top hanging point. I build mine on a ledger generally which is pretty easy to move. You can also use thinner treads or reduce the existing sub tread, or just keep the carpet. This problem comes from new flooring, put new flooring at both ends of the stairs, then the whole stair is back to correct. Might have to make a little landing of the new floor. Lots of options, just pick one and commit, it's going to be fun.

[Jim Becker]

Steve, there are a few photos earlier in the thread that show the underside of the stringer...it's an "interesting" arrangement.

[Steve Rozmiarek]

Steve, there are a few photos earlier in the thread that show the underside of the stringer...it's an "interesting" arrangement.

Lol, yes it is! I'm guessing there is actually not a little riser back on the top step as it's drawn, the second floor rim is likely the backer for that top riser. I'll also wager that there is a ledger under the stinger tops that is not drawn in. OP definitely has better CAD skills than me, but I know I struggle with drawing stairs, so maybe it was just omitted for this drawing. I know I would if I was just drawing the layout to save 30 mins drawing time.

[John K Jordan]

A builder friend had this issue once and ended up removing and rebuilding SOME of the steps from the bottom, maybe 6 or so. He carefully rebuilt enough steps so there was a gradual change, maybe 1/8" max difference between any adjacent step. I tried them up and down and the change was so gradual I could not detect it (and I'm real sensitive about that!). The stairs passed inspection.

JKJ