7m RSJ Bearing size

[stash2014]

Hi all,

Hopefully having a 7m RSJ installed soon & an extension built, had a quote from a builder of £3000 to fit the steel, (not including the cost of the steel), because of the existing layout & i guess for easiness he suggested cutting the wall each end at the reveal for the windows, this would give a 600mm bearing which to be honest is way too much for what I'm trying to achieve, my question is:

is it possible to have a 200mm bearing, or less with a 7m RSJ ??

i'm assuming we would have to dig out and reinforce the floor and possibly build a new bit of wall & padstone or have the pictureframe/goalpost steel uprights (I know it depends on a hundred variables but 600mm bearing each end is a deal breaker)

standard (1940's ?) terraced house no loft conversion etc upstairs above the lounge is a room the same size with a stud wall, joists run at 90deg into the brickwork.

 

[noseall]

standard (1940's ?) terraced house .

Terraced? Where are you going to site the crane?

 

[stash2014]

no need, it'll probably be 2 x 3.5m with a sleeve.

 

[^woody^]

Your engineer will tell you what size bearings you can have, and what foundations you may need. Not your builder.

 

[stash2014]

i know that, I'm asking if anyone has experience of a 7m steel with a bearing of 200mm or less.

 

[rules&rulers]

Your engineer will tell you what size bearings you can have,

i know that,

So what has your engineer quoted ?,they could be wrong or something similar,

 

[stash2014]

Nothing yet, she's visited & im due to see her next week, just want to know if what I am asking is even remotely achievable.

 

[tomfe]

Yes you can do 100mm bearings, but this has to be designed by a SE.

 

[stash2014]

Thank you, just didnt fancy asking her for something patently ridiculous.

 

[Doggit]

You could put in upright steel supports for the end bearing. Bit more work, bit more cost, but achieves what you want.

And as always, get a couple more quotes.

 

[tony1851]

For normal domestic loading on a 7m beam, a 200 bearing is perfectly feasible.
But if you are taking out the back wall of the house at ground floor level, has your SE considered overall stability,
because your building inspector certainly will.

 

[^woody^]

i know that

Yeah, of course you do.

 

[stash2014]

Yeah, of course you do.

I knew she'd tell me, thats what im paying her for, I just didnt want to put it to her if it was a ridiculous thing to ask for, hence the question.

 

[stash2014]

For normal domestic loading on a 7m beam, a 200 bearing is perfectly feasible.
But if you are taking out the back wall of the house at ground floor level, has your SE considered overall stability,
because your building inspector certainly will.

It is a back wall.

 

[John D v2.0]

Yes the builder wants to keep 600 because it will buttress the side walls and avoid any danger of the house falling sideways. Make it too small or remove completely and you have to make sure the neighbours didn't do the same thing, or put in moment resisting connections ie goal post with the side channel chased into the wall.
Everything is possible at a price, your SE will let you decide on the options