Do I really need wind posts?

[RichTraff]

I'm building a single storey extension. It's 6.4m wide and will have a 4.8m bifold door.

One SE, that I have paid for, says I need windposts as the opening is over 2/3 of the wall length.

Another SE (that I haven't payed for his services yet) says I do not need windposts as I 3 bricks (700mm) either side of the opening.

It's a bit late to put windposts in now as I've built up to damp.

Can I convince the original SE that I don't need the wind posts? Or should I just pay the second SE to provide calcs showing I don't need them?

Your thoughts please.[/b]

 

[cjard]

Which would be cheaper?

 

[RichTraff]

Paying the second SE would be cheaper and easier.

I was wondering if anyone had some fact that I could tell my current SE that would convince him it's ok not to have wind posts.

 

[pinenot]

I would ask this of your building control officer, after all they are empowered to decide the final pass, as it were...pinenot

 

[tony1851]

I'm building a single storey extension. It's 6.4m wide and will have a 4.8m bifold door.

One SE, that I have paid for, says I need windposts as the opening is over 2/3 of the wall length.

Just because the opening is > 2/3 the total length of wall, it does not mean you need windposts.
It would be straightforward for an SE to do calcs to prove that the returns you have would resist the wind load without windposts.

 

[RichTraff]

My building control guy isn't bothered whether I have wind posts or not, as long as the calculations show that it's ok.

Disappointed that the first SE won't budge on his calculations. The fact he's twice as expensive as the second guy I'm getting in is also very frustrating.

Hey ho.

Thanks Tony1851 for clarifying that I don't necessarily need the wind posts.

 

[pinenot]

I've held meetings before with SE's before where there is a very basic disagreement over something basic. My findings are- there are no correct or in corrects in the building industry, only alternatives to liability. That's the reason your man from building control is for either, so bear in mind what happens if anything goes wrong, liability i.e. insurance back up comes into play. I neither condone one or the other, but I'd be surprised if the new SE will put his money where his mouth is, so to speak...pinenot

 

[tony1851]

The reason the first SE won't budge is that he's already done the calcs for a windpost and would look at bit stupid if he suddenly said 'sorry, you don't need them after all'.

A 700 return each side will be perfectly adequate to counter the bending moment applied by wind load. Cut your losses and pay SE no. 2 to do the figures.

 

[RichTraff]

Ok, I've now cut my losses and paid the second SE to do calcs for me. No wind posts or anything

I've spent £225 more than needed :'(