Stair stringers - 3x LVLs or 4x 2x12 KD?

[Mattilac]

Getting ready to build some interior stairs. Will be my first time. Been reading and watching videos.

Here are some general dimensions:

14 steps
7.25" rise
11" run

Overall length of the stringers will be between 15-16'. Stair width will be around 36-40".

Given these specs, would you go with 3x LVLs (I guess 11-7/8" or 14" wide) or 4x regular 2x12s for the stringers?

 

[Rusted Nut]

I’d go LVL’s, finding decent straight 16’ 2x12’s is difficult.

 

[jar944]

Have you considered housed stringers.

 

[Dagny]

I used white oak full 2x12s for mine. The trouble with lumber yard stuff is the points break off.

 

[jkeyser14]

LVLs all the way. They won't bow, warp, or twist over time.

 

[The Cobbler]

I know this wasn't your question, but This is a good resource for layout /measuring stairs if you need help with that

 

[GrayFlattop]

LVL - no question. You just won’t find “regular” 2 x 12 stock that is as worth a damn when you start and once you cut out the stringer, they will all move differently as their moisture content changes.

 

[jar944]

LVL - no question. You just won’t find “regular” 2 x 12 stock that is as worth a damn when you start and once you cut out the stringer, they will all move differently as their moisture content changes.

Another reason not to go with a cut stringer.

 

[Youngandfree]

If you have the room to make the stairs longer, I'd do 6.5" rise. I replaced the 2 steps on my front porch with 3 steps, and its magnificent. My back 2nd story deck is getting replaced next month and its getting 6.5" rise.

 

[PCustoms]

If you have the room to make the stairs longer, I'd do 6.5" rise. I replaced the 2 steps on my front porch with 3 steps, and its magnificent. My back 2nd story deck is getting replaced next month and its getting 6.5" rise.

I have long legs, I HATE little steps.


@Mattilac go with the LVL.

I was buying 2x12x12' to get 2 ~4' stringers. They ****. Splits and knots all over screwing up the layout. I can't imagine trying to get 16'

 

[ddurrett896]

Getting ready to build some interior stairs. Will be my first time. Been reading and watching videos

No help other than to recommend blocklayer (link below) for the cuts. Built a couple sets of stairs and the calcs are perfect.

Stair Calculator App - Inch

Calculate stair rise run stringers head-room and upper floor opening dimensions - Wood and concrete stairs - Inch

www.blocklayer.com

 

[Firebrick43]

If fancy stairs I definitely would do housed stringers being that long as @jar944 suggested.

If down into a basement I would cut stringers in the normal fashion on a 2x12 but screw/laminate those to an uncut lvl on the sides for an easier and very strong set not weakend by cuts.

 

[mike93lx]

Have you considered housed stringers.

For a first time stair builder?

 

[PCustoms]

No help other than to recommend blocklayer (link below) for the cuts. Built a couple sets of stairs and the calcs are perfect.

Stair Calculator App - Inch

Calculate stair rise run stringers head-room and upper floor opening dimensions - Wood and concrete stairs - Inch

www.blocklayer.com

See post #6

 

[jar944]

For a first time stair builder?

Everybody starts somewhere, might as well be the deep end.

 

[txvwnut]

I did 2 x 12's for stringers when I did my stairs as that's what I had available.

 

[Shoester]

I used 2x12's. If I had to do it over again, I would for sure go with LVL's. I wasn't paying enough attention when I bought the 2x12's and ended up wasting two boards because they had too much of a bow in them, and another one because a couple of the 'points' broke off after cutting. Lesson learned.

 

[carlaisle]

I would use a taller rise and longer run, but that's my preference, not yours. You should size the rise and run to what you find most comfortable. If you can find straight 2x12s, they'll save you a good bit of coin but the LVLs are much easier to work with. The broken off points can easily be glued back on; the knots and splits are much more of a challenge to work around.

 

[danfromsyr]

I do hope there's a plan to have them supported in middle that's a long span for stringers.. esp cut stringers.

if your not going to put a mid span support
I'd do cut 2x12s fastened to an uncut LVL as mentioned above.. then the LVL is a 'beam' and is rated for a 16ft span.

 

[billconner]

Research shows that missteps - which lead to falls which lead to injuries - increase as tread depth decreases and as riser height increases. It's a fairly straight line increase in missteps for treads down to 11 3/4" or so, then they increase a faster rate. Likewise as riser height increases to around 6 1/4 or 6 1/2", it's a straight line. Taller and the number of missteps per use increases at an increasing rate.

Up to code max rise and to min tread depth it's all personal choice. I usually aim for 6 x 13, and may push that a little on interior stairs - like 6 1/2 x 12 1/2.

I wear size 13 shoes which are over 12" overall, and not having to turn my foot increases stability. The more you rotate you foot the less stability.

 

[Mattilac]

Thanks for all the feedback and suggestions. I couldn't resist the idea of a stiffer, stronger staircase, so I went ahead and grabbed a bunch of 14" LVLs. (I'm building two stairs, and will use 4 stringers for each.)



One of the stairs may eventually have a wall on both sides to support it, but the other staircase might be free standing so I figured the thicker LVLs @ 4 across should help. We'll see how it feels in practice.

 

[mike93lx]

Thanks for all the feedback and suggestions. I couldn't resist the idea of a stiffer, stronger staircase, so I went ahead and grabbed a bunch of 14" LVLs. (I'm building two stairs, and will use 4 stringers for each.)



One of the stairs may eventually have a wall on both sides to support it, but the other staircase might be free standing so I figured the thicker LVLs @ 4 across should help. We'll see how it feels in practice.

4 each is the right move.

Curious, what did those run you?

 

[Mattilac]

1-3/4x14" x 16' 2.0E LVL = $144.80 each here in southern NH

 

[PCustoms]

1-3/4x14" x 16' 2.0E LVL = $144.80 each here in southern NH

Can I go back and change my answer?

 

[mike93lx]

1-3/4x14" x 16' 2.0E LVL = $144.80 each here in southern NH

Hey, sometimes I hate money too

 

[Mattilac]

Are LVLs significantly less expensive in other parts of the country? Around here it's always been about 4-5x dimensional lumber.

 

[GrayFlattop]

Are LVLs significantly less expensive in other parts of the country? Around here it's always been about 4-5x dimensional lumber.

About 8-9% less around here - not sure if that’s significant.

 

[Mattilac]

Well that wasn't too bad. Stringers came out great. Gotta love the big beam saw.

 

[The Cobbler]

looks good, but do you really want that top stair that's flush with the deck floor? they look like they're going to be some mighty tough stairs there

 

[Mattilac]

I thought about it and figured it offered more bearing support and a touch more space under the stairs for my mechanicals.

Is there a downside to that top stair being flush with the mezzanine floor?

 

[PWC Repair]

looks good, but do you really want that top stair that's flush with the deck floor?

Maybe it's a really small landing? LOL!!

 

[billconner]

I thought about it and figured it offered more bearing support and a touch more space under the stairs for my mechanicals.

Is there a downside to that top stair being flush with the mezzanine floor?

It does make "hanging" them simple. Structurally you just need to anchor bottom to floor. The top anchorage bears no load - just leaning against upper floor. Also can be easier to assure to rise is equal. So many stairs where too rise is greater than rest because of finished flooring not being taken into account.

 

[The Cobbler]

Is there a downside to that top stair being flush

I think its subconsciously easier to navigate your first step off the deck than a stair tread , because that's normally how we do it.

 

[Mattilac]

Subtreads and risers cut from scrap Advantech and 5/8" ZIP. Glued and screwed. Very stiff feeling stairs. I'm happy. Plan is to eventually install hardwood treads.







On to the second staircase, which will be from the mezzanine up to the attic. I'm now considering doing an open riser design with 4x12 treads since I'm not planning to close in the space under the stairs.