Steel beam(rsj) placement for purlin strut supports??

[jozh12]

Hi, this is my first post so thanks for any help that i get!

I am removing and upstairs stud wall from an 1840's cottage, that is perpendicular to the brick walls at either end. The wall has 2 purlin struts sitting on top of it supporting the roof. I have had a SE round who has done all the calculations for the size steel and the padstones. What i would like to know is, is could i set the padstones flush into the top of the wall and have the steel sitting on top of the walls instead of set into the walls so that i can avoid lowering the ceiling. And if so, how would i go about stopping the moving under the force from the purlin struts?

Thanks again!

 

[^woody^]

You can potentially put the steel at whatever height your want. But the engineer should be detailing this, and not be doing half a job.

I don't know what you mean regarding the purlin struts. But again, that sounds like something the engineer should have specified.

 

[noseall]

Is it your intention to position the steel at the same height as the roof joists? My guess is that you will need a ridge beam also (or instead of), if you want to do this.

 

[jozh12]

You can potentially put the steel at whatever height your want. But the engineer should be detailing this, and not be doing half a job.

I don't know what you mean regarding the purlin struts. But again, that sounds like something the engineer should have specified.

He worked out his calculations with it in the same place as the current beam, with the top of the beam flush with the top of the wall, what i wanted to know is whether i can raise it 100mm so that it sits of top of this wall instead of in the wall flush with the top. With regards to the purlin struts, if the beam is sat on top of the wall, how would i stop it moving horizontally, and sliding across the top of the wall.

Its highly likely that i will get someone in to do this, but i thought i would work out what work it requires before hand.

Cheers

 

[jozh12]

Is it your intention to position the steel at the same height as the roof joists? My guess is that you will need a ridge beam also (or instead of), if you want to do this.

By roof joists do you mean the joists holding up the ceiling below? And if so, why would i need a ridge beam, am i missing something?
Thanks

 

[noseall]

am i missing something?

Perhaps I am - like a drawing or summat.
I'm imagining that the beam will clash with the ceiling joists....?

 

[jozh12]

Sorry i took so long to reply. Here is a drawing to try and explain what i mean a bit better.

 

[Leofric]

Looks like you would be cutting into the ceiling joists and the struts You need your structural engineer's advice on whether this is possible and how it might be done.

 

[noseall]

Basically you want to insert the beam at a point where all the roofs connective strengths come together?



It would be simpler to conceal the beam with a lowered false ceiling. Or re-build the roof?

 

[jasonzyx]

First off, I’m only a DYI’er.
If he temporarily supported the purlins during installation of the beam (which he is surely going to have to do while he removes the wall) couldn’t he relocate the purlin supports into the web of the beam, rather than on top?
He’s still got the problem of preventing beam moving sideways after installation, but if it’s sitting on brick walls I wouldn’t expect that to be much of a problem, assuming he has room to add a few bricks each side.
To OP, are the walls gable walls, hip roof or eaves?

 

[tomfe]

Use 2 new steel beams and put new struts at 90 degrees?

 

[^woody^]

 

[Leofric]

But the engineer should be detailing this, and not be doing half a job.

You need your structural engineer's advice on whether this is possible and how it might be done.

With respect to others' comments/suggestions but are you going to get your structural engineer to detail any alternative arrangements ?