Stair stringer size/availability

[cwr]

Hi folks

I'd had in mind something like 300mm X 50mm for stringers, but finding that the best I can get locally is 269 X 32mm. Only leaves a min of 126mm once the triangular bits have been cut out. Is that just what is used and ok, or am I right in thinking it's a bit lightweight?

Thanks

[tonyshouse]

We used to buy 9x1 1/2 abs get it planed on one face and one edge. Need to leave 50mm above the nosing, now my ex employees glue and pin triangles of MDF to hold each tread (MDF window boards and risers MDF ) generally carpeted to reduce noise 

[tonyshouse]

i.e. don’t cut sawtooth 

Edited March 3, 2022 by tonyshouse

[SimonD]

3 hours ago, cwr said:

Hi folks

I'd had in mind something like 300mm X 50mm for stringers, but finding that the best I can get locally is 269 X 32mm. Only leaves a min of 126mm once the triangular bits have been cut out. Is that just what is used and ok, or am I right in thinking it's a bit lightweight?

Thanks

 

For my temp construction stairs I laminated some plywood sheets and cut into 36 x 300 stringers like this. I used three stringers across an 800mm wide staircase. It's strong enough but bouncy! Although it is entirely unsupported between floor and landing. I may keep these stairs and finish with a veneer as I'll be building some understair cupboards which will be framed to support staircase. You're probably best routing or as @tonyshouse has suggested, glue some triangles for risers and treads if you want a solid staircase.

[cwr]

So am I as well just getting 47 X 200 carcasing (can't find CLS available locally that big) and attaching triangles to it? Will be about half the cost and not much  more work.

[tonyshouse]

I prefer 225 to 200 more likely 220 in practice 

[Rishard]

Is this a permanent stair? For the price of a straight flight of stairs I would just buy something off the shelf. Your 32x269 would be plenty strong enough if your grooving in the treads/risers. The strings want fixing to the walls if your near a wall. Strings would be best out of joinery grade pse.