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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Replacing staircase timber vertical support with s https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1593596890 Message started by a413982567 on Jul 1^st, 2020, 10:48am

Title: Replacing staircase timber vertical support with s
Post by a413982567 on Jul 1^st, 2020, 10:48am

Hi

On the middle floor in my townhouse, the staircase to the upper floor is supported with a timber 170mm x 70mm x 2500mm

I am renovating the entire house and the handrails will be steel; I'd like to replace the support with a steel one - it will be slimmer and match the ironmongery.

Can anyone tell me:
- How to calculate the load (that the timber can bear)
- What the equivalent steel CHS would need to be

Thanks in advance

Title: Re: Replacing staircase timber vertical support with s
Post by woodsmith on Jul 2^nd, 2020, 7:42am

A change like this would need building approval from the local planning department. They will want calculations from a structural engineer who will be able to work out exactly what you need to do. Bear in mind though that they will want this to be made fire resistant, as steel is not as good as wood in a fire. There are special paints available which may be acceptable otherwise you would need to box it in with fire resistant material.

Title: Re: Replacing staircase timber vertical support with s
Post by CWatters on Jul 3^rd, 2020, 11:20am

Its also not just about the vertical load. A thin metal tube might be strong enough to take the vertical load but could buckle if a kid swings on it creating a horizontal load.