Buidling spec for stairs ?

[Paultynton]

Two years ago I purchased a new house. Over the 2 years the stairs gradually started to creak, cracks have appeared between the stairs and the wall. On further investigation I find the stairs are made from a very thin hardwood ( 5mm thick) and MDF. The thickness of the wood is so small that even the stair grippers when nailed in place show through. The stairs have also not been secured to the walls. Surely this can't be right. Can anyone advise if there is a specification the builder should have built the stairs to.

Many thanks,

Paultynton

 

[Scrit]

No wonder I keep getting undercut on stairs!

 

[Paultynton]

Thanks for the reply but sarcasm I can get anywhere, DIY advice I am after.

Paultynton

 

[splinter]

The treads on the stairs should be 25mm.approx ,is it the risers that are 5mm thick?.

Yes stairs are now made of MDF ,and they should have been fixed to the wall

 

[Scrit]

There are actually specs. within the Building Regs as well as the relevant BS specs for components of straight flights in domestic dwellings which were BS.585art 1:1989 and BS.5395art 1:1977. The Building Regs are much more concerned with the minimum width, going, etc., than with the materials - for recommended component sizes you need to look at BS.1186art 1:1986 which lists minimum finished thicknesses of members for stairs with closed risers and states that open riser stairs will need to have thicker components.

The relevant data is:-

1. For stairs up to and including 990mm over strings

Tread thickness = 20mm
Riser thickness = 14mm (wood), 9mm plywood
String thickness = 27mm

2. For stairs exceeding 990mm but less than 1220mm over strings

Tread thickness = 27mm
Riser thickness = 14mm (wood), 9mm plywood
String thickness = 27mm

The problem is that a lot of people (including builders ) seem to be unaware of the BS standards, and although I thought that the BCO should be enforcing them, I'm unsure of whether installing to non-BS spec. is an offence or not. I'm just the poor b***** joiner who makes them at times. .

Your staircase seems well under spec. and as for securing it the main place a staircase is secured is through the top riser into a floor joist and I'd agree through the wall-side stringer at a couple of points, although this is not necessary if it has been secured at lower floor level in some way.

I trust that answet satisfies you're needs. And with stairs like yours it's still no wonder I keep getting undercut at times.

Scrit

 

[Paultynton]

Thanks for taking the time to reply, that information is most helpful.

I shall get onto the NHBC for their comments on the lack of compliance to the required specification.

Most appreciated,

Regards,

Paultynton