External staircase and balustrade

[Auchlossen]

I require to construct an external staircase, up about 2.4m., in two flights with 90deg turn on landing.

I am struggling to resolve the design and construction.

Stairs to be precast, which enables sockets to be inserted for bolting on balustrade. This is not the cheapest solution, but it ensures a robust construction. Blockwork supporting structure.

The balustrade and handrail are the problem.

Architect suggests cladding blocks and balustrade in larch to match elsewhere.

Engineer says balustrade must support wind pressure of xyz N/m2. SE suggests using proprietary metal structure, round galv tubing, bolted to stairs,  which will then be designed to withstand the wind pressure.

But my conversations with various handrail cos have not led to any scientific strength analysis, Esp because the handrail systems are designed as safety rails, as in old people's homes, and not for stairs.

Previously suggestion from contractor was to use timber handrail structure, cos that is easy to construct. But SE then says uprights must be bolted on at every step, which defeats the purpose of using cheap timber construction.

I wonder if the timber cladding could cover the blockwork, but leave balustrade open at every other batten, thus reducing wind pressure issue.

Or use stainless steel metal framework for balustrade, for which there are many systems available, with some alternative infill that is not wind resistant, but still complies with BC requirements of no gaps ≥ 100mm, no horizontals that might be used for climbing on. Maybe polypropylene mesh? Fastened how?

SE wants metal framework so that handrail can be bolted securely on to it.

Any experience or constructive suggestions out there to help me out of this catch22 situation please.

[Auchlossen]

My solution FYI is to use a standard galv metal tubular handrail [eg Brundle] [as in guard rails in old peoples homes], bolted to the side of the stairs. DDA hadrail will be attached to this structure. The whole will be clad in Scottish larch in 100/60 vertical overlap cladding to match that used elsewhere. This should be relatively cost effective, satisfy the SE, and be easy to construct. Pre-cast stair is under construction now.

[CC45]

We bought metal stairs off ebay - it was a school fire escape.  3 days with a welder etc saw it firmly fixed in place.  Thankfully my farm upbringing furnished me with good fabrication skills.  Balustrade will be fabricated post xmas - uprights in 40mm box with 19mm tube every 97mm.  What has surprised me is the cost - its going to be 1k, still this is way less than anything new.

 

Merrt xmas to all