Concrete stairs first step nightmare

B-D-P--

Ok, so I had floors calculated to finish 220mm above foundations.
Got hollowcore + precast stairs delivered all fine and to the mark.

Fast forward and the doors and windows went in.

Fast forward a little more was talking to screed rep and he suggested I raise the insulation 15 mm to get right up to door level once tiled.

I agreed, and only now realize that the 1st step rise is now going to be 15mm lower than the rest..

How big an issue am i in?
Any ideas on resolving the issue?

Will it be a constant affair of people tripping on the stairs?

delfagio

So including the floor covering on the upstairs landing your saying every step will be for example say 170mm but the last step will be 155mm.

I'd say realistically 15mm won't cause too much of an issue as its the last step coming down or the first step going up. It would be worse if it was in the middle.

This kinda think happens in houses anyway where some houses might have a laminate or carpet of say 10mm of the ground floor and they change to solid wood floor which could be 18-23mm. Or thicker tiles which all result in the last step losing approx 10mm height

BryanF

It’s out side of tolerance of build regs. I’d take issue with this. If I was unfamiliar with the stairs whether it’s the first or last step, if your not expecting a different rise, it’s a hazard.

Lumen

12mm plywood on first step.
9mm plywood on second step.
...

:pac:

B-D-P--

Lumen wrote: »

12mm plywood on first step.
9mm plywood on second step.
...

:pac:

OK just in case anybody reads this in future, this is not a good idea, will worsen the issue.

@bryan if the step that's different still meets regulations for rise, is it still against regulations simply because the fact it's different?

sydthebeat

The bottom step of a concrete stair is usually constructed a bit higher to take account of third floor finish.

Has this been accounted for?

Where exactly is construction at at the moment?
Ground floor and first floor Screed poured?

B-D-P--

@Syd
Yea originally I allowed for the 220 finisihed floor. But Didnt consider this when adding the 15mm to screed.

Screed is poured yes.

BryanF

B-D-P-- wrote: »

is it still against regulations simply because the fact it's different?

It doesn’t meet regs, your allowed approx 2mm +/- from the average rise.

wayoutwest

You could fix 15mm treads to all the treads and the landing area - this will maintain 170mm step rise but will require a 15mm step down threshold detail at doorways that come off landing (not sure if this would contravene regs)

Gumbo

B-D-P-- wrote: »

@bryan if the step that's different still meets regulations for rise, is it still against regulations simply because the fact it's different?

Pretty much yes.

TGD K allows for a variant is riser height, but that height must be maintained for every riser in the flight.

The tolerances come from I.S. 158:1987 and BS 5395-1:2010.

What has your Assigned Certifier / Agent said on the matter?

B-D-P--

wayoutwest wrote: »

You could fix 15mm treads to all the treads and the landing area - this will maintain 170mm step rise but will require a 15mm step down threshold detail at doorways that come off landing (not sure if this would contravene regs)

Yea I thought that, Then you have to rise your 1st floor by 15mm to match.
Wish it was that easy

wayoutwest

B-D-P-- wrote: »

Yea I thought that, Then you have to rise your 1st floor by 15mm to match.
Wish it was that easy

Threshold step down detail i had to do at my place - the landing was 13 mm higher than the room coming off it.

BryanF

wayoutwest wrote: »

Threshold step down detail i had to do at my place - the landing was 13 mm higher than the room coming off it.

As that at the top of a stairs? Lethal.

OP your getting some dangerous advice here. Suggest you discuss with your arch/Eng

delfagio

Can the precast stairs be removed and a new insitu staircase be cast to give every step an equal rise.

Probably cost 2-3k though

wayoutwest

BryanF wrote: »

wayoutwest wrote: »

Threshold step down detail i had to do at my place - the landing was 13 mm higher than the room coming off it.

As that at the top of a stairs? Lethal.

OP your getting some dangerous advice here. Suggest you discuss with your arch/Eng

No Bryan - not at top of stairs ...like i said - the image simply shows how threshold can be used to accomodate (and define) 13mm step down from landing level to upstairs room, which happened to be 13mm lower. Can you see a problem with my suggestion (#9) of adding 15mm Ply to both treads and landing (to maintain an even step rise)? There would only be a 15mm loss of doorway height. It would obviously not work if the O.P requires continuous flooring between landing and the upstairs rooms coming off it.