Stair riser height variation?

[Vera16]

Does anyone know how much variation in riser height is acceptable under Building Regs? The finished floor level will mean the bottom riser is 13mm shorter than the rest (190mm). 

 

Not an ideal scenario I know...

[Mr Punter]

10mm is normally tolerated but they are very unlikely to pick up on this.  It is better on the bottom riser than, say, mid flight.

 

If you were to carpet the stairs and have vinyl on the bottom landing there would be no difference in rise anyway.

[Vera16]

Thanks. I'm not installing vinyl on the ground floor though ?

 

Someone else is telling me only 1mm is tolerated.

[ProDave]

I think the wording is they should all be the same with no stated allowable tolerance. 

 

Hope your BC inspector does not notice?

[Vera16]

Maybe. I'm more looking for ammunition to ask the builder to change them. I don't really want to live with that short step. They measured incorrectly using screed height and not finished floor height.

[PeterW]

13mm on a 13 step flight is 1mm per step. Unlikely you can get that accuracy anyway so you are not going to get a rework at much better tolerance so I doubt 1/2” will be noticed by the BCO and it really isn’t worth it. 

[Vera16]

But 13mm on one step would be noticeable surely?

[Mr Punter]

53 minutes ago, Vera16 said:

Thanks. I'm not installing vinyl on the ground floor though

 

The point is that people change flooring throughout the life of a building and on the bottom step 13mm will not matter.  A thick carpet and underlay or some wood flooring can be over 20mm.  All you will do is piss off the builder.

[PeterW]

14 minutes ago, Vera16 said:

But 13mm on one step would be noticeable surely?

nope - think about a runner with a feature varnished bullnose step ..? 
 

The runner with underlay will be more than 10-12mm thick, the bullnose will have nothing yet they will “appear” the same. 
 

BCO won’t be getting a tape measure out ..!

[nod]

Wow 

Who would notice 13 mil

I bet Building control won’t 

[TonyT]

Building control won’t notice that, they aren’t interested….

 

 

[Nickfromwales]

7 hours ago, Mr Punter said:

 

The point is that people change flooring throughout the life of a building and on the bottom step 13mm will not matter.  A thick carpet and underlay or some wood flooring can be over 20mm.  All you will do is piss off the builder.

+1