Steel calculations

[tony1851]

@ Woody - you beat me to it!!

 

[charliegolf]

So an SE would always visit the site to make evaluations of the site-specific conditions?

 

[^woody^]

@ Woody - you beat me to it!!

Us young 'uns have the edge

 

[tony1851]

So an SE would always visit the site to make evaluations of the site-specific conditions?

N

So an SE would always visit the site to make evaluations of the site-specific conditions?

Not necessarily, they can often work off plans and some further info about the building.

 

[^woody^]

So an SE would always visit the site to make evaluations of the site-specific conditions?

No. That's were the experience come in.

One semi tends to be the same as the next. And one 1940's house may well have different features to one built in the 90's.

So its possible to know as near as dammit the factors that will influence the beam design, so site visit may not be necessary but the right questions certainly will be - again that's competence and experience. But there will be times when the person should visit site, even if he chooses not to.

The alternative is to factor in greater capacity to take account of unknowns, but this tends to lead to massive beams that are not necessary or even some elaborate post and beam system that is way over the top.

Many councils will have worked out what beams will be required for all common domestic situations and as long as your situation fits the scenario and you select one of the standard beams you wont need to provide calculations to justify it. That's not a cop out, as someone has spent some time analysing things and come up with what beams will work, and it just save times repeating old work. But again the competence comes with making sure that the situation does mirror the one that the beam was intended for.

 

[charliegolf]

Cheers both- every day's a school day.

 

[Wolverhampton123]

Just some Feadback if interested

The timber Is related as on one of the drawings you sent attached, it shows a timber purlin so we have generated the load that purlin will impose on the steel beam we have designed.

 

[tony1851]

So presumably the purlin is existing, and is propped off the masonry wall at first floor level, which in turn is to be supported by the 178 x 102?
Seems to make sense now.

 

[Wolverhampton123]

No idea if I need to do further works, just a little random to have a timber spec with no details, yet another question I need to ask.

 

[tony1851]

As I see it, there's nothing additional to do.

The wall at first floor level is going to be supported by the 178 x 102 beam which is bolted to the inner of the two main beams. At present, it looks as though the first floor wall may be supported off the floor.

In the loft, there may be a purlin propped up off the first floor wall. The SE seems to have added the load from that purlin to the weight of the wall, to arrive at a suitable size for the beam supporting the wall.
(In other words, the new beam is supporting not just the weight of the first floor wall, but probably part of the roof via a purlin prop as well - if that makes sense?).

 

[Wolverhampton123]

Fantastic, understand perfectly now mate, great help.