Rotting stair string

[Stringman_uk]

Hi all
Bit of back story.
The lower level of our (1865) house is a bit weird in the the dining room is at the front of the house and is below ground level, the kitchen is at the back (same level) but opens onto the back garden.
The stairs go up to the next level "right to left" in the middle of the house, dividing the kitchen and dining room.
The dining room was tanked about 20 years ago and originally had one doorway at the foot of the stairs. (on the right)
Previous owners knocked another doorway through under the stairs (on the left)
I suspect this has compromised the "tanking"

I have noticed that a couple of the lower sections of the stair string have rotted through. Only noticed when i knocked it and it left a bit of a hole.

I wondered what my options are here?
As a temporary fix I could dig out the rotten wood, treat and fill it.
But in the long term can the stair string be repaired or would it need to be replace?
If it needs to be replaced doe that mean either a whole new stair case or if not does the staircase need to be removed for a new string to be fitted?
Thanks in advance

 

[Deleted member 174758]

I wondered what my options are here?
As a temporary fix I could dig out the rotten wood, treat and fill it.
But in the long term can the stair string be repaired or would it need to be replace?
If it needs to be replaced doe that mean either a whole new stair case or if not does the staircase need to be removed for a new string to be fitted?
Thanks in advance

Forget filler - it has absolutely no structural strength. Should only be used for aesthetic repairs

You can't easily replace a string, reusing the existing treads, risers and wedges, either.

If this is a straight, simple stair I think the best (and least complicated) option would be to replace the entire stair, re-using the existing newels, spindles, handrails, etc as appropriate.

Failing that it may be possible to remove the bottom section of the stair, say the bottom 3 to 5 steps, and make up and splice in a new section. The difficulty is going to be getting an exact matching section made up as the old stairs aren't going to be made from any sort of standard section. In addition the join between the two sections always be noticeable, and the additional work which may be necessary to support the remaining section of old stair could end up being very intrusive, depending on whethervthe underdrawings could be seen

Personally I'd replace the stair; I'd walk away from thevsplice approach unless it was a listed building as it will be a lot more awkward

 

[Stringman_uk]

Job
Many thanks for the reply.
The bottom few stairs are above a void between two walls so would not be visible.
The stairs have no handrails or newals etc ( see pic)
My wife hates the fact we have carpet(with muddy dog) so would probably be very happy with a whole new staircase that could be stained and varnished.
I have had a poke in the hole and you can see the attached pic. thats the worse bit and the stair above and below are less affected.
Many Thanks

 

[Deleted member 174758]

Having seen the photos now I think I'd just rip out and replace. It won't be any more work.