This question has probably been answered before in another thread, but I couldn't find it.

I'm installing new solid treads on top of a 34" wide, pre-built, mortised, plywood stairs with stringers that had been carpeted. My first floor is ceramic tile. Each step currently rises 8 inches from the top of one tread to the top of the next.

When I put the solid treads (1&1/16th thick), on top of the existing treads, the height from the ceramic floor to the top of the first tread will be a bit over 9 inches. Step 2 through 6 (this is a split level) will be 8 inches, and the last step into the second floor a bit less than 8 inches (I'm putting 3/4" hardwood on the room the steps lead to.

Is this a problem? I had seen some threads about code requiring the rise of each step to be within some sort of range, but I don't know what that is.

I can't raise the first floor level, since that's ceramic, and I don't want to have to tear that up just to raise the level of the floor. It looks like it would be too difficult to disassemble the existing stair setup to replace the current tread with the new tread.

I don't think the height difference will bother me, I was just wondering if there would be an issue if I came to sell the house.

You have what is called a rise problem; when the height of the steps are uneven. National stair building guildlines allow for up to 3/8" variance and it sounds like you have a little over an inch. You have a few choices. Remove the existing "rough" treads if possible. You say they are mortised in to the skirts/stringers then that isn't possible. You will then need to select a thinner material. You can either build your stairs with flooring OR build solid treads that are thinner to allow for the proper rise. If you used 3/4" stock for your treads, you will lower the first step to about 8 and 3/4". And if you add 1/2" ply to all the other steps before installing your 3/4" treads, your rise will be an even 8 and 1/2". This will all be within stair code. And it will matter when you sell the house because if the buyer hires an inspector (which is common), the inspector will most certainly notice and point this out. It may not be a deal breaker but you never know. This is important as this is one of the areas many home builders get dinged on by local building inspectors. If you are unsure of how to accomplish this, I recommend getting some local, professional advice. A stair builder/ master carpenter how can access the situation and come up with the proper remedy.

Thanks Gary, but by using 3/4" stock and half inch ply on all the treads but the first one, I'll end up with stair heights of 8 3/4, 8 1/2.....8 1/2, and finally 7 1/2 inches on the last step. I suppose I could only do the 1/2 inch plywood on the second step, and end up with 8 3/4, 8 1/2, 8, 8, 8, 8.

As I see it, I have a few options. I was planning on installing Bruce Kempas 3/4 inch in the upper room. Bruce also makes a 3/8" engineered Kempas (need to see this in person to see how well it matches) with the corresponding stair tread bullnose. If I use this, then the first and last step will be 8 3/8, and all the middle ones will be 8.

Or, I could find a lumber yard that makes 1/2 inch stock (not too sure how difficult this is). Yes, there'd be 1/2" variance instead of 3/8" in the first step, but I doubt that would be an issue.

Or, if I could find somebody with an industrial size band saw to re-saw the 1 1/16 treads in half. Not likely to find one of these bad boys in my neigbor's garage.

I was leaning towards the 3/8" engineered flooring route, but my neighbor who's in the constrution business (he built his own house) is trying to discourage me from doing that. He was worried (as am I) about the long term durability of 3/8" engineered wood (especially that little stair nose piece).

In your first post, you mentioned putting 3/4" in the upper room. Therefore, the height difference on that last step would not be 7&1/2" but 8&1/4", which would all pass muster regarding stair codes. You also may need to sheet the upper area with whatever thickness plywood to make up for the rise issue. I agree with your neighbor about 3/8 engineered. IMO, it is usually a cheaper product. Can you find something in a 1/2" that you like? Lots of great engineered floors with thicker wear layers in 1/2", 9/16" and such. I just did a staircase in 7/16" Lauzon Next Step. It worked out nicely but make sure you get the 7/16" nosings. I was sent 3/8" and that made for a hassle. IN your situation, you need to do whatever it takes to keep the rise within code. Don't think it won't matter. It will. If someone falls down your stairs and finds your stairs are out of code, you could be in for a large lawsuit. Also, it will matter in the sale of a home. In CA., we are required to mention anything that we are aware of that would affect the value of a home, including code violations.

Phil, if you build the stairs the first way you mention, with a 1" difference at the bottom, you will notice it. It doesn't seem like much, but your body will be able to tell a difference, and it will be apparent every time you use the stairs.

Intead of trying to re-saw the new wood to a thinner dimension, why not rout a huge rabbet on the underside? Figure out how much of the new wood will overhang the old tread, then use a router to make the rest of the wood maybe 1/4" thick, and you'll gain 1/2". It's a little had to describe withoiut a sketch, but imagine the letter "d" then rotate it 90* counterclockwise ... you end up with a thin tread and a fat nosing. If you bed it well with a good adhesive, like maybe PL, it should be supported enough so it dowsn't crack under load.

Thanks, E, but I can't imagine the amount of time it would take me to router a dozen treads like that.

I had a flooring installer over and explained the situation to him, he agreed that while solid 1 1/16th treads were a bit much, using 3/4" wood on the treads should be fine. Honestly, every single application of additional hardwood to treads (as opposed to replacement of treads) must have encountered this same quandary. Assuming that the stairs were of even rise before adding the treads (not necessarily a valid assumption), unless you were willing to add the same height of materials to every level of the house that the stairs touch, you'll be out of whack somewhere, either too short or too tall on a rise.

I'm going to go ahead and install 3/4" wood on all the treads, and to soften the height difference from the ceramic floor to the first tread, I'm going to get a small, thick, oriental style rug to put on the ceramic tile at the bottom of the stairs. These carpets are usually 1/2" - 3/4" thick, so that should even everything out.

This got me thinking - how does the code relate to stairs with carpeting & the height of carpets. I measured my pad & carpet that were on the steps, and it worked out to about 1 1/8" high. Even compressed, it was a half inch high. So I'm guessing I've been out of code all these years. Never noticed a problem.

Here's a simple image I made to show what I was talking about.

Thanks to everyone who offered suggestions. This is a very helpful site.

Phil, I'm suggesting that you only rout the first tread. That will reduce the difference from 3/4" to less than 1/2".

E,
Won't work! Let me explain. The difference from the first floor to the first step is 9&1/16" with the 1&1/16" tread. The rise to the rest of the steps is 8" until we meet the top, where it is a "little less than 8". Now if one takes 1/2" off the bottom of the first tread only, the rise (from the first floor to the first step) will be 8&9/16". Since the rise on the rest of the staircase is uniform, 8", that means the rise from the first step to the second step would be 8&1/2". So far so good; only a 1/16" variance. But now we go from the second step to the third step and there is a rise of 8" because all the rise of the staircase is uniform and nothing was routed off the second tread. What you have done is move the rise problem further up the stairs is all. 1/2"off in the middle of a staircase is definitely a code violation. By going with 3/4" flooring all the way, Phil is still going to have a violation on that first step but by placing an area rug right there, He can make that up. Not sure whether or not that would fly with an inspector. My idea was to use 3/4" on the first step and then add 1/2" ply plus 3/4" on the rest. The top floor could be sheeted to make up for the rise issue at the top. All I am trying to recommend is a way to build the stairs and keep it within the universal stair codes. None of the other proposals do that.

Unfortunatley he has a problem, and we're trying to make a silk purse out of a sow's ear. I question if the throw rug will do the trick, but it's one option. My proposal does not solve the problem, but it makes the differential at the bottom much closer to normal. And you're right, it does nothing for the top.

This is one of those "glad it's not my problem" situations.

Come on, your trying to rethink this way too much.


With the original carpet and padding on the steps, wasn't it every bit of 8¾ to step up?

Logic tells me it was.

Floorguy - exactly the point I was trying to make. With the original carpeting, the first step was taller than the rest already. Can't say I've ever noticed a problem before.

I'd be willing to bet that for the majority of renovations involving stairs, the 3/8 inch rule is regularly broken. Even with original construction, I'm guessing that the subcontractors installing the stairs doesn't necessarily know what will eventually be installed as flooring (tile/vinyl/wood), which theoritically should be taken into account.

The kids are already starting to complain about the "hard" steps - I removed the carpet last week and it's the bare plywood steps. Any bets for how long after I put in the new wood steps that they'll be asking for a runner - which will throw off the measurements again?

GARY you said in this post you did a 7/16th staircase. i got called in to rescue a floor in the making. they used a brad gun to install the whole floor. obviously that is wrong. i was curious if you could use the bostitch stapler with a 1/2 inch adapter? are the staples going to be too big or do you HAVE to use the bostitch "laminate" floor stapler? it might be off topic but i couldnt find anywhere else it was talked about...

The 7/16 " flooring was Lauzon Next Step. It can be nailed I think, with the right nailer. A Bostitch M111 FS is too large, you'll need something else. But this product does better gluing it down as the tongues are small. The manufacturer of the flooring should make recommendations. Follow those.

they suggest the bostitch laminate gun. its the stapler that is trigger accuated as opposed to mallet accuated. i have used them before and dont feel like they secure the boards tight as it does with the mf. thanks for the quick reply, these "pros" really botched his floor up.

The Bostich floor runner, Senco SLS-20HF, PortaNail 435, High-Pro as-4090, etc... will all work with thin gauge flooring. As long as it shoots a 18-20 gauge staple. Unless it says gluedown or floating only.