Staircase & Trimmer

Hello,

Conundrum, advice needed if possible - my own job not my house. I have an existing straight flight staircase that's been butchered by previous home owner "it's coming out".

The main issue due to the position of the existing trimmer 4x3 and the lack of space at the bottom of the stairs I can only get the new staircase made with a tread going of 197mm to fit which is illegal.... It's not a massive problem as the job isn't under BC.

Ideally I would like to put a staircase in that complies but I'd also like to get rid of the storey newel, so the conundrum is what size trimmer?

The trimmer has to span 1.5mtrs in can be housed 100mm either side into masonry walls I was thinking 8x2 doubled or maybe 6x3 doubled C24 or even 8x3 doubled not enough head room for 9 inch though??!

Thank you in advance...

Can you redesign the stairs with winders at the bottom so that it then complies with the minimum 220mm tread, maximum 220mm rise, 42 degrees max pitch ,2m min headroom and then meets Building Regs Part K so that you are not building an 'illegal' staircase with 197mm treads

My stairs was built and installed in the 30’s , only 200mm step and 46 degrees. Every house in the street is the same .

foxhole said:

My stairs was built and installed in the 30’s , only 200mm step and 46 degrees. Every house in the street is the same .

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So Your staircase doesn't comply with current bldg. regs because it was built in the 30's; chirpychippy is installing a new staircase that he would prefer complied with current building regulations

Winders at the bottom of the stairs would obviously require 2m min clear headroom so would depend on the existing stairwell headroom.

Leofric said:

So Your staircase doesn't comply with current bldg. regs because it was built in the 30's; chirpychippy is installing a new staircase that he would prefer complied with current building regulations

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He’s already said he doesn’t have the room .

foxhole said:

He’s already said he doesn’t have the room .

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He has said he doesn't have room for a straight flight staircase The suggestion for redesigning the stairs with winders at the bottom might work if the headroom is available.

As it is an existing building, he could still have a straight flight with 197mm treads.
There is no 'legal' requirement for 220 min. treads.
If replacing a staircase, the important point is to ensure that the replacement is no worse than the original.

chirpychippy said:

Ideally I would like to put a staircase in that complies

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As I keep saying a stair with 'decent' size treads might work with winders at the foot of the stairs if headroom is available - isn't it worth looking into
It might not be a current bldg. regs situation in this case but 220mm minimum tread size under regs now is there for a reason

I put this job on hold until I looked at every conceivable option.

I had already looked at the winder option but this restricts an already very restricted passing point for a push chair at the bottom of the existing stairs, plus I can't achieve the min 50mm going on the threads at the newel post.

I looked at a landing with a straight flight but this creates the same issue as the winder.

So, I'm going to photograph the existing staircase which isn't original. Its a steel staircase with open risers the treads are soft wood of varying thicknesses since modified to include 6mm MDF risers held to planted strings with a combination of expanding foam and nails, the steel staircase is "Nailed" not bolted to the Trimmer which has split "probably due to the weight and the ****e fixing technique".

The homeowner has young children so Ive accro'd the existing stairs just in case.

I'm quite comfortable that although the new staircase won't comply it'll be a lot safer than the pile of ****e that's in there at present...

Thank you for all of your suggestions, much appreciated.