Structure Calculations over the top?

[purplemonkey]

hi,

A fiend of mine recently had some work done, and there structural beams seem to be totally over the top, from a visual point of view. I have just had some calculations done by a different engineer and these seem totally over the top too. I'm renevating a place so I'm replacing some older beams. I just took out a 4x2inch beam ( I appreciate this was crazy small) to be replaced by a 4x10inch c24 beam (very hard to find), this seems excessive.

I'm wondering if anyone knows if engineers are known for overspeccing beams nowadays for some reason, or are there egineers out there who dont quite know what they are doing?

 

[tony1851]

I'm wondering if anyone knows if engineers are known for overspeccing beams nowadays for some reason, or are there egineers out there who dont quite know what they are doing?

Probably both; 4 x 10s seem big to put it mildly.

Are these floor joists?

What is the span, and what are the beams supporting?

 

[purplemonkey]

these are beams spanning 4.2m to support the floor joists which will span max 3meters between beams.

 

[tony1851]

In that case, they are binders and will be supporting a considerable dead- and live load. Deflection will probably be critical here.
Have you considered using steel instead.

 

[purplemonkey]

can't use steels due to heritage reasons. I wanted to go hard wood but our engineer didn't know the calculations for hardwoods.... should have jumped ship after that, but he'd already done a load of work elsewhere...


anyway I've ordered the timber, just wanted to get a feel for other people opinions.