Loft Stairs, angle and tread size

[FresnoBob]

Hi people,

Sorry to be a pain, I don't seem to be able to find what I'm looking for (or I'm useless....always possible lol ). Has anyone an idiots guide to loft staircases from the perspective of building regulations?

I appreciate a staircase can't be too steep an angle, and must retain a certain tread depth. I've seen alternating tread stairs and the like. I'm just wondering what the maximum angle in degrees you can have would be if using one of these alternating tread jobbies?

Thanks in advance.

 

[^woody^]

For alternate tread steps, there is no given pitch, but the minimum rise and going dimensions are defined in Part K

You can also have a vertical ladder

But both of these are very much last resort options, and the BCO will tend to want to explore a normal stair flight unless they are technically or practically not feasible

 

[freddiemercurystwin]

http://www.planningportal.gov.uk/Pp...gportal.gov.uk/uploads/br/BR_PDF_ADK_1998.pdf

 

[DevilDamo]

So to summarise (as per FMT's link)...

Max. rise (220mm)
Min. going (220mm)
Max. pitch (42 degrees)

You need to provide min. headroom of 2m, which can be reduced to 1.9m for a loft conversion.

 

[jeds]

There is no prescribed maximum pitch for alternating tread stairs, but there is a practical maximum determined by the minimum going and maximum rise. It generally works out about 63°

 

[DevilDamo]

And BC would only suggest alternating tread stairs be used where a traditional stair cannot be accommodated.