builderbill

A reader's Stairs question: Stair riser gap?




Peter B.   from   Gold Coast, Australia   had this Stair riser gap question.

As I understand stair design, the BCA requires that the vertical gap between the top of one tread and the underside of the tread above (in an open stair) must not permit a 125mm ball to pass between the treads.
What type of obstacle would you recommend to comply with this requirement?

Bill's reply

Hi Peter, This is a real pain, you would have to say that 99% of stairs of this type already built, don't comply with this rule. A typical 40 thick tread and a fairly average rise of 175 gives a gap of 135. Just 10mm too much.

  • The only method that I have used for this is to screw a timber batten, 20 to 35 thick to the underside of the treads. Set back 25 to 35 from the edge of the tread. That is in a similar position to where a vertical riser would be.
  • We have done this and only nailed the battens on, knowing that the owner would remove them after the final inspection.
  • With external precast concrete steps at 50 thick, we have just tried to keep the rise to no more than 165.
  • I once considered using cut lengths of 8 or 10 SS rod in a stair that had SS balustrades, but in the end we still put the batten under the treads. Just simpler and people just don't notice them all that much.
Cheers
Bill.

If you didn't find exactly what you are looking for try this search tool that will search the site and the web.


"What can be added to the happiness of a man who is in health, out of debt, and has a clear conscience?
Adam Smith 1723-1790


"When we build, let us think that we build for ever."John Ruskin 1819-1900


coates hire
Hire Equipment
hafele
Furniture Fittings - Architectural Hardware - Electronic Locking Systems - Technical Hardware
BuilderBill sponsorship

BuilderBill Books


building maths
Building Maths

Stair Design
asbestos ebook
Asbestos Book

Calculator Pages.

Concrete yardage calculator

Reader's Questions.

Questions and answers.


 

 



Please Note! The information on this site is offered as a guide only!  When we are talking about areas where building regulations or safety regulations could exist,the information here could be wrong for your area.  It could be out of date!  Regulations breed faster than rabbits!
You must check your own local conditions.
Copyright © Bill Bradley 2007-2012. All rights reserved.
Page copy protected against web site content infringement by Copyscape