Bracing bars on railings

[Thrashsmith]

Is there a rule of thumb of any sort for frequency of dog legged bars to brace iron railings at the posts?

Some railing images you see online have no bracing dog legged bars, but some of the older ironwork railings have them really often.

It's something I've often wondered, but in any case, the reason for asking now is I've been asking to quote for some long lengths of 1m high railings to go on top of a 1m high masonry wall - taking the total height to 2m. The spans of railings will be 10m & 20m.

The railings themselves aren't very tall so structurally may not need bracing, but visually it might look more appropriate if they were braced...?

 

[Agroshield]

Can you clarify that the braces are at 90 degrees to the run of the railings.

One consideration might be the width of the wall, as the foot of the braces (1) have to be fixed to something, (2) transfer their force into something, so if there is an intermediate pillar in the wall, that would be a good place for a brace.

There might be some regulations concerning allowable deflection when a certain sideways force is applied to the railing. You would brace according to length and height in order to stay within that number. The building regulations could be a quick place to look.

This is an example of the requirements for handrails. They are not relevant at all to a fence, but kind of give you a flavour of how the issue is assessed:

https://www.balconette.co.uk/content/uploads/73e57685-ff4c-4af9-8750-d1b03bfd062e/b1nb6060300150bp141117r-balcony-1-with-66x75-posts-(60x60x5-shs-with-300x150bp).pdf

In the railing world, the braces to which you refer seem to be called 'back stays'. I could not find much on how often you need one though.

See page 34 of pdf here: https://ballantinecastings.co.uk/wp...-Exterior-Cast-Iron-Railings-etc_WEB-v1.3.pdf

Also see: https://alpharail.co.uk/technical-drawings/

 

[gaz1]

Is there a rule of thumb of any sort for frequency of dog legged bars to brace iron railings at the posts?

Some railing images you see online have no bracing dog legged bars, but some of the older ironwork railings have them really often.

It's something I've often wondered, but in any case, the reason for asking now is I've been asking to quote for some long lengths of 1m high railings to go on top of a 1m high masonry wall - taking the total height to 2m. The spans of railings will be 10m & 20m.

The railings themselves aren't very tall so structurally may not need bracing, but visually it might look more appropriate if they were braced...?

yes there is but it has to do with what customers want and what they will complain about

if you dont use dog legs and that ( wind ) gets hold of that fencing then it will bend force or even fail over the years

the worst being the ones stuck on top of walls many customers dont want a dog leg but they will be soon back complaining your work isnt up to standared when the wind gets hold of that fence and rips the lot down

many times its the owners fault as they dont use through fencing and instead fit wind proof panels ( we want privacy )

if you make any up put it in writing and make them sign it that they are aware that they have been advised without a dog leg theres a possible chance it will blow over

braces are determined by height, wind, and length

 

[piman]

Hello Thrashmith,

As Agroshield says , you need to be able to brace to something which is difficult on top of a narrow wall, and unsightly to boot.
An unbraced open fence is not too bad but if solid panels are fitted it would need very strong uprights and feet, not forgetting the fixing to the wall to withstand strong winds, and I mean strong.


Alec

 

[gaz1]

heres some old ones

our park is old and the stone wall is still original you can see the next dog leg wall post on the second photo

 

[addjunkie]

I wonder if much of the bracing is good old over engineered Victorian quality.

 

[Gareth J]

Imo, if it needs bracing, bracing looks right.

How many braces per 100m or whatever measurement is hard to say without lots of maths. In a bespoke application, easier to just put up the vertical fence and wiggle it. Space braces to bring wobble down to acceptable levels. Will probably look right then too.

 

[nickk]

Are people able or likely to lean on the railings?every 2-4m I’d like.

 

[gaz1]

Are people able or likely to lean on the railings?every 2-4m I’d like.

the ones ive shown you you could climb over them

but the cast iron railings was bedded into the stone all the way along and as shown with the stones set back was the dog leg

but as already seen the painting is in a bad state of repair already

so you can guess why the local council removed the railings and scrapped them, as cant be bothered to paint them

as you can see with just the gate posts they was nice railings on the local park as only the photoed side had them on the rest of the park is stone walled

 

[Thrashsmith]

Thanks all, good food for thought