Suffering from wind... again

[ToughButterCup]

Wind. Makes me wince now. Here's why Understandable isn't it?  Worse when it happens at night from some point of view,  better when it happens at night because people in the main are in bed.

 

But tomorrow deals up the next dose of wind during the working day.

And that makes me wonder about scaffolding and limits.

What are safe wind limits for working on scaffolding?

 

I suspect there are a good few of us on here  who sail boats, some who fly, many who walk on hills. And we'll be aware of  local turbulence and unexpected, sudden wind-shadow.

 

Our wall fell over because the wall faced east, had an unrestricted fetch all the way from the Pennies with only Forton Services on the M6 to tubulate the lower wind. Worse, we are on the leading edge of an East facing slope and the wall that fell starts two meters above ground level.

Perfect for slope-soaring gliders. The opposite for scaffolders. It's not steady wind I worry about it's turbulence.

 

So, what's safe and what's unsafe? 

Try, just for me, please, try to keep it straight eh?Just a little bit.

[MikeSharp01]

Morning @recoveringacademic! The safe limits for scaffolding are a movable feast and depend upon the construction method used. So the wider the base the higher you can go safely unsupported. There are windage tables and calculations and the large contractors insist on something like this from their scaffolders. Your scaffolders will be able to advise you but given you are only going up one long pole length, by the looks of it, you have the whole thing as a homogeneous wall around the building so the challenge won't be the scaffolding but the walls it is supporting and perhaps here is the rub. Scaffolding is designed to give you access to the building rather than prop it up. This means that the building normally has to stand on its own or have independent support that is nothing to do with the scaffolding. You can get the scaffolding to take some of the lateral loads by putting diagonal bracing down to the ground on the outside and putting upper cross linking high capacity beams, above the roof ridge level, which transfer the lateral loads across the scaffold structure and back down to the ground via the diagonal bracing on the other side. However even this would need the services of a structural engineer to be sure it would / could take the wind load on an otherwise unsupported wall from a squall in Lancashire. I think the general advice around getting Durasol to advise of sequence / pours etc in a windy situation is best but independent, of the scaffolding, support is probably going to be your only route.

 

As an example of the building supporting the scaffolding - not the other way around, here is a pic of a skyscraper scaffolded using bamboo!

 

[ragg987]

Is there some form of wind breaker you could consider - like sitting on a windy beach behind the break? My (very limited) understanding is that a solid obstruction is less desirable as it promotes turbulence, possibly difficult to predict, but something that "slows" the wind could be more effective - e.g. a hedge effect. I suspect providing a temporary barrier of this type is not going to be easy, and my creative juices are a bit dead, but is there anything on site already you may be able to use?

[ToughButterCup]

Well @ragg987, this next lot will hit us from the west and south west going through to south. We are well protected by slightly higher ground and two lines  of trees, so I'm not to worried. And the contractor has shuttered those faces. Oh that he had done so to the east . But.

 

I'm not so concerned about the scaffolding itself. I have concerns about people. People on the scaffold. Who sets the limit on the wind speed , wind gust speed in which people may work? 

 

My comfort limit is different to that of others.

[Stones]

Scaffold debris netting wrapped on the outer face of the scaffolding? Almost identical to garden wind break fabric (but usually cheaper) should help reduce wind impact for those on the scaffold, and might help shelter the actual structure a little.

[ToughButterCup]

Ah! @Stones, good idea. Thanks!

Ian