Advice on stair rise and going please

[swissbob]

I will soon be tackling a garage conversion which includes a 630mm step down (once the insulation, chipboard and wooden floor are laid). I intend to make a small set of steps, but am unsure of whether to go for three or four.

At three steps, the rise will be 210mm. Four steps will give 157mm. Both are within the regulations, but which one would feel/look better?

Our house stairs are 190mm, so I am concerned that 157mm might feel like fairy steps. 210mm would also mean less intrusion into the room, but will they feel oddly high?

 

[DevilDamo]

Did you seek building regulation approval for the conversion?

The max. rise of a private stair is 220mm and the min. going is 220mm so there's no reason why you can't install 3no. steps with a rise of 210mm and a going of 235mm, thus maintaining the max. 42 degree pitch. The actual going is 233.2mm but I don't think tolerances are that precise

 

[swissbob]

Did you seek building regulation approval for the conversion?

Yes, he is due to come round next week before I start any of the work.

The max. rise of a private stair is 220mm and the min. going is 220mm so there's no reason why you can't install 3no. steps with a rise of 210mm and a going of 235mm, thus maintaining the max. 42 degree pitch. The actual going is 233.2mm but I don't think tolerances are that precise

Sounds good, thanks. Do you have any thoughts on how the height would feel? I was planning on a 250mm going (using these), so they will be slightly shallower than the 42 degrees.]

 

[DevilDamo]

When I usually specify new stairs, I usually go with a rise of 200mm and a going 220mm so having a rise of +10mm (i.e. 210mm) is hardly anything to worry about, providing all risers are the same and do not differentiate.

Also, there's no harm in going for an increased going... just means more of the room, which contains the steps will be taken up (i.e. 750mm).

 

[joinerjohn]

Out of interest,, When I worked for the local council, on many occasions I'd be called down to the Council House to do minor repairs, put up whiteboards, change locks etc. At the rear entrance there is a set of stairs that go from the entrance right up to the top in 7 flights (one from ground level at rear to ground level from front of building, and 3x2 flights between each floor.
The bottom flight has a difference in rise of about 30mm from all other flights.
Unless you know about this, when coming down several flights of stairs, you reach this one and almost trip up/down the stairs.
A bit bad but it's been like that since the place was built in the late 40's early 50's. I don't know what they'd do if there was ever a real fire there and staff had to use this as an emergency route, I reckon half the staff would be crushed when they all fell down the last flight.

 

[DevilDamo]

If it's existing/old, then there's not a lot that can be done about.

There's no reason why all flights of stairs have to have the same rise/going. Providing the rise/going does not change on the one flight, then it should be fine. You never know, they may have had issues with floor to floor heights. In this day and age, you would try and keep floor to floor heights the same through and thus the rise and goings would also be the same, where practical.

 

[joinerjohn]

Yes it is , Devil..... Has been like that since it was built. Must admit if you'd been to the top floor and came down all flights of stairs, you really noticed the change when you hit the bottom flight. I did ask the H&S officer about it once, as it could be a potential problem if the offices had to be evacuated in a hurry and he promised to look into it.
Luckily these stairs are not used by the public. Had they been I think there would have been lots of claims by now.

 

[DevilDamo]

Yeh! What would I worry about the most... stairs having unequal risers/goings, which may lead to a slight trip OR being burnt in the event of a fire. I'd favour the trip one