Reducing the run of existing stairs (ie moving the top step)

[GCarnegi]

We have just broken through from our house to our new extension, and found that there is a discrepancy of approx 100mm in the position of a wall! Ouch!

Anyway, that would mean that as you arrive on the top step of our existing stairs, there is only 800mm in front of you before the bathroom wall (there was previously 900mm).

Pic 1 below shows how it is right now.

Untitled

• GCarnegi
• 9 Feb 2012
• 1

Building control officer says it HAS to be 900mm, and we have to either move the new walls and remove granite, breaking into the bathroom behind the existing wall, or create a diagonal wall between the old and new rooms (pic 2).

I had a more unconventional idea which I wanted to run by you guys before mentioning it to anyone. (Pic 3)

As we are replacing the stair carpet anyway, I was wondering if it would be an idea to screw new treads onto each existing tread of the stairs, but make them each 1/2" shorter (less deep), so the top step of the stairs ended up being about six inches farther from the wall that it used to be, giving me enough room to make a new cavity wall and keep over 900mm gap between the top step and the wall.

Obviously, I would put new stair risers underneath the noses of the new treads.

 

[ladylola]

What you are in effect doing is increasing the pitch of the stairs by your idea. It would work assuming the new pitch doesn't exceed regs and also assuming your new shorter threads don't impinge regs either.
What space do you have at the bottom? It may be possible to move the whole stairs by that 100mm if you have the room.
Either way whatever route you choose it will involve a considerable amount of time and work

 

[freddiemercurystwin]

How wide is the stair at its thinnest?

If your drawings are accurate your BCO is being a bit of a tool!

 

[ladylola]

Just had another thought. If you build on top of the exsisting stairs then there will be a discrepancy at the top between your top thread and your floor equal to the thickness of the matewrial you build your treads out of.

 

[freddiemercurystwin]

Is the bathroom wall existing or new?

 

[GCarnegi]

Bathroom wall is existing (directly in front of you at the top of the stairs).

Stairs are about 950 wide! (older house)

 

[ladylola]

I think freddy asked about the width of the stairs to confirm your drawings aren't done to any scale, the 900mm section is far wider than the 950mm of the stairs
To be honest I think the diagonal wall option is your best bet. It's far less work to get it all passed and won't create problems elseware except maybe with moving furnature about.
Of course I wouldn't suggest you remove the end of the exsisting wall to get it passed and then replace it how you want after the BCO has gone

 

[freddiemercurystwin]

Ah OK, @ ladylola, I asked about the width as the width of the stairs determines the sizes of the landings which I can see now is where the BCO is coming from.

@ the OP yea go with knocking a bit off the wall to make it diagonal exactly as ladylola said rebuild it afterwards, you should be able to leave the lintel intact and just adjust the nib up to say 200mm beneath the head of the opening and then just feather it back in if you see what I mean.