Stair Stringers

[CarolinaNomad]

I'm building my first set of stairs next week and I'm at rough framing stage.  Thanks to Peter Halle, I'm going to cut the stringer using his technique.  My question is to how many stringers will I need for support the 42" wide stairs.  Since there will be a landing between the floors, the length of stringers will be less than 10 ft.  I figured I would use 4 LVL's, one on each side and two 16" on center.  But I've read that others have used two Stringers on the outside of stairs and one in the center.  I haven't found in my research on how to calculate how many stringers are needed.  Or what's the best approach.

I planned on building the stairs exactly like the below youtube video.

 

[peter halle]

WoW!  Someone watches my videos?  [big grin]

Honestly I would use 4.  The distance between stringers would ultimately be determined by the thickness of the walking surface.  For instance, if you are building a rough stair that will be covered with carpet and using 2x material then you could get by with 3 stringers.  3/4 material, definitely 4 - in my book.  5/4 material, somewhere in between or go up to the more conservative.

You don't want a call back for squeaky stairs.  After looking at that video I would make a couple of suggestions.  At the top of the stairs I would add simple 90 degree framing connectors where the stringers meet the ledgers to reenforce that joint.  Also the video didn't show the use of a level to level side to side.  You might want to at least check with one versus just relying on measurements.  Measurements can be flubbed, an accurate level's bubble can't be.

Wishing you SUCCESS!

Peter

 

[Rob-GB]

I can't help you  [sad]
Of the many many lots of stairs I have built i have yet to build one in the American fashion, however a photo tutorial of your build would be really interesting...so bug the heck out of Peter and gain as much info from him as you can [poke] then post up the build  [thumbs up]  ;D ;D ;D
Looking forward to it.

Rob.

 

[TooManytoys]

That's the way I've built stairs, including the added suggestions Peter gave above.  The only thing I might suggest although I admit it's overkill is to add strongbacks to the inner stringers as well just to keep all the the stringers having the same (modulus of elasticity) bending strength so they carry the load evenly.

 

[rizzoa13]

When in doubt over build it.

If the stairs are for you you'll never remember the extra few bucks and time spent, if it's for a job just figure it into the price. Framing is the last place to try to save time and money.

Just an FYI If its exterior and your using a Trex deck type product you need to frame on 12" centers.

 

[cfullen]

@ 42" wide, I am using 4 all day.  I can't tell you how many houses we go into that the framers thought that 3 would be sufficient.  I always end up dropping in 1-2 extra stringers in to beef it up.  Otherwise, they would be calling me because of the stairs squeaking.  Most of the framers in my area don't really have knowledge of stair building, in the proper way at least.  I am always left with a blank face, and a question to the contractors... "you want me to work with THAT???"

 

[CarolinaNomad]

So for the first set of stairs I've done,  I'm quite happy with the results.  The treads are level and solid as a rock. The only thing is two of the strangers are 1/16" short of the other two. So before I glue and screw them down, should I shim the short ones or will the glue fill in the difference? . I screwed the treads down just for the time being because it took me longer than expected to build.

Didn't want to slow down framers.

I only screwed up one tread and it was the first one.  Peter's technique works great only when the stringer has a consistent width. The one I screwed up on,  the lvl went from 11 7/8 to 11 3/4.

Thanks for the great tips.

 

[peter halle]

Shim and glue!  Don't want a squeak.  I thought I warned about non parallel or unequal.  LVL's shouldn't vary.  Sorry.

Peter

 

[CarolinaNomad]

I thought the same thing about lvl's. But glad I made the mistake.  I learned from it and helped me create a routine that kept me from making more mistakes. For instance, I laid out the points along the edge and draw the triangle as a way to cross check. And thank goodness I did,  I placed a couple of points along the edge incorrectly and caught my mistake when drawing the triangles.

 

[CarolinaNomad]

Another question, the next stair case has an opening of 70 11/16 and a rise of 56 1/2" which works out to be a 7" rise 8 steps but 70" opening. So should I add a 3" ledger at the top or bottom?  Or split the difference top and bottom? And is 2 5/16" enough meat to sit on the landing?

 

[wow]

Another question, the next stair case has an opening of 70 11/16 and a rise of 56 1/2" which works out to be a 7" rise 8 steps but 70" opening. So should I add a 3" ledger at the top or bottom?  Or split the difference top and bottom? And is 2 5/16" enough meat to sit on the landing?

I'm a little confused. Your rise is 56 1/2" so your step rise will be just a hair over 7" like you said.

So, is the run of 70-11/16" between floors, i.e. an actual opening that you need to fill? Or does it land on a floor where the run is less critical?

 

[CarolinaNomad]

Yes,  the actual built opening/run is 70 11/16.  And since the staircase will be 70" long, I need to add a thicker ledger. I'm leaning toward adding 3" ledger at the bottom of the staircase.

 

[wow]

Yes,  the actual built opening/run is 70 11/16.   And since the staircase will be 70" long, I need to add a thicker ledger. I'm leaning toward adding 3" ledger at the bottom of the staircase.

so 70 / 7 steps = 10 inches per step tread or run. is that a problem, or am I missing something?

 

[tjbnwi]

The rise on the second set needs to be 7-1/16", run needs to be 10-1/8". You fit the stairs to the opening not the opening to the stairs.

The numbers are for the rough dimensions you gave. If you have not calculated for the finished floors- if there is a difference from upper to lower floor or tread material your stairs may not be compliant. On new construction you must know what the finished floor surfaces will be and adjust for them is your staircase calculations.

Tom

 

[CarolinaNomad]

The rise on the second set needs to be 7-1/16", run needs to be 10-1/8". You fit the stairs to the opening not the opening to the stairs.

Tom

I'm an idiot. Makes total sense to increase the run.  So, I increased the run to 10 3/8" and have 2" of the stringer sit on the landing and notched the portion of the landing from the stringer.

another lesson learned, when changing the tread from 10" to 10 3/8" remember to cut the top tread for a 10 3/8" not 10" tread.

 

[tjbnwi]

The rise on the second set needs to be 7-1/16", run needs to be 10-1/8". You fit the stairs to the opening not the opening to the stairs.

Tom

I'm an idiot.

Welcome to the club.

Stairs are the most difficult simple right angle triangle you'll ever build.

Tom

 

[CarolinaNomad]

To give you an update to an old thread, below is a picture of the stairs (I haven't placed the plywood riser yet).

[attachimg=1]

Thanks guys for your help!  They have held up quite well during construction.  Now it's time to clad them.  I'm pretty sure I will be asking questions about how to clad them.

Jeff