Can I Give Calcs to Builders without PI?

[zakmuh]

Thanks all and Tony, thanks for the reiteration.

Talking about who blames whom for any failure, it should be the BC or their own SE, as they had checked the design and approved it. Please correct me if I'm wrong..

 

[tony1851]

If there was a failure caused by errors in your calcs leading to an incorrect spec. of beam, for instance, then it would be your responsibilty.
But how do you describe 'failure'? For example, a steel beam can 'fail' by allowing excessive deflection, causing cracking in the structure above, but falling short of collapsing. Deflection is a serviceability issue rather than a limit state. Remember that Building Control only have to apply the regs in so far as they affect health and safety, so your beam could allow serious cracking to occur, but that would not necessarily be a safety issue. Though the client would be on your case.
The bottom line is: do your figures once, and get them right first time.

 

[^woody^]

The calculation method that you use (should use) whether BS or EC, includes factors that will mean that the resultant beam has greater capacity than what it will ever need in service.

So the risk is not so much the beam, but the installation and the associated supporting structure - slenderness of walls, foundation loading and all that. But even so, for domestic work, there is not a great deal to go wrong with those either.

So its actually very difficult to design a beam that wont be suitable, and its equally difficult to make a mistake, because there is not much to go wrong. The failings tend to be in the installation, or deviation from the design, or subsequent alterations. Non of which relates to the beam design.

Bear in mind that building control have no liability for checking and approving any beam design.