Steel beam installation

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I am embarking on installing a steel beam to support a load bearing wall. I design bridges so have done the necessary beam calculations, I have a few queries about the building side of it though. Any help gratefully received as I will be installing the beam myself (with help from friends of course)! And yes building control is being consulted before you ask.

The beam (UB 178x102x19, 3m span) is to replace an internal wall which supports the joists and stud work for the rooms above. I believe it is a breeze block wall. The beam is to span between an internal wall and the outside cavity wall and it will sit inside the ceiling with the joists fixed to each side of the beam using joist hangers on timber runners set into the web.

My questions are these (plan attached for reference):

1) The minimum bearing length is 100mm, is it wise to support the beam on the breeze block inner leaf of the cavity or leave 100mm at the end of the wall which is removed to add support to the beam. I will be partly fixing the beam into the inner leaf to give lateral support, however this does not need to be the full leaf.

2) On the internal (other) end, the beam will be at the end of a supporting wall. Is it wise to have the beam at the end of this wall or should I remove part of the adjacent stud wall and extend the wall by a brick length to give a better bearing/support.

3) With 1.1 N/mm2 bearing stress is it wise to install a spreader plate or remove a breeze block and install some engineering bricks to support the beam?

Sorry to ask so much, but want to get the plans as accurate as possible before the building control officer slates them!

Thanks

View media item 20917
 
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I would have thought a two or three course padstone on the cavity wall side will be ok.

I am not so sure about the internal end other than you may need to leave a return of masonry with a shaped padstone unless an s.e. is prepared to sanction otherwise.

Out of my league i'm afraid.
 
1) The minimum bearing length is 100mm, is it wise to support the beam on the breeze block inner leaf of the cavity or leave 100mm at the end of the wall which is removed to add support to the beam. I will be partly fixing the beam into the inner leaf to give lateral support, however this does not need to be the full leaf.
Hard to say without more information but if the wall is acting as a lateral support then you should leave a decent sized pier. If it isnt i would remove the whole thing as it looks nicer. Its pretty hard to post fix lateral supports from a beam into a cavity wall and prove it without removing half the wall.

2) On the internal (other) end, the beam will be at the end of a supporting wall. Is it wise to have the beam at the end of this wall or should I remove part of the adjacent stud wall and extend the wall by a brick length to give a better bearing/support.
Do a masonry pier design of the wall.. failing that maybe rebuild a 215x215 pier at the end to bear your new beam onto. The stud wall may not have any foundations so extending the wall wouldnt help.

3) With 1.1 N/mm2 bearing stress is it wise to install a spreader plate or remove a breeze block and install some engineering bricks to support the beam?
Depends on the quality of the blockwork, that said its always better to reform a bearing unless the blockwork is new and you know its strength. With 1.1N/mm2 an eng brick padstone each end would be fine.
 
Thanks for the replies, looking further at the end of the beam which is supported on the end of the wall this is going to need a pillar. A 215 x 215 pillar is going to be installed, tied into the existing wall.

Question is, as this is going to need to be founded on the house foundations, how do I remove a portion of the concrete floor and then reconstruct this providing a suitable DPC!
 
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Thanks for the replies, looking further at the end of the beam which is supported on the end of the wall this is going to need a pillar. A 215 x 215 pillar is going to be installed, tied into the existing wall.

Question is, as this is going to need to be founded on the house foundations, how do I remove a portion of the concrete floor and then reconstruct this providing a suitable DPC!
The new pier can go on the same foundations the old removed wall was on so just a little more hacking out..
What is your current ground floor made from?
 
The ground floor is concrete, it is an 80's house. I am planning on using the same foundation, so breaking out part of the floor to get to the foundation will be needed. My issue is how to deal with the membrane in the concrete floor when I put it back. Do I need to ensure I overlap it or is there another way to make sure it doesnt get damp at the joining surfaces?
 
The ground floor is concrete, it is an 80's house. I am planning on using the same foundation, so breaking out part of the floor to get to the foundation will be needed. My issue is how to deal with the membrane in the concrete floor when I put it back. Do I need to ensure I overlap it or is there another way to make sure it doesnt get damp at the joining surfaces?
Depends on what kinda of concrete floor, if its a ground bearing slab then the wall will be built off of the structural slab which will be below the screed.. and you wont even touch the dpm.
If its a beam and block or hollowcore type floor then normally just below the floor will be a dpm in the wall which you can reinstate in your new pier..

Your only gonna know for certain when the wall comes down what it bears onto.. but check if you have any airbricks in the external walls can indicate a subfloor void and thus a supended beam and block kinda floor.. but not a guarantee..
 
The concrete floor is solid with no external venting. I was assuming the wall foundation is a strip below ground and then the concrete floor is higher than this but not structural? Therefore I will need to break out the floor to enable me to found the pier on the strip foundations. It is just what I tell Building Control on the plans before I start which matter, although once I get started I may find something totally different!
 
The concrete floor is solid with no external venting. I was assuming the wall foundation is a strip below ground and then the concrete floor is higher than this but not structural? Therefore I will need to break out the floor to enable me to found the pier on the strip foundations. It is just what I tell Building Control on the plans before I start which matter, although once I get started I may find something totally different!
Not normally strip and ground bearing slab for an internal wall (1980s).. but you can check the edge of your concrete against the wall if there is a soft joint there then as you say then youll find a strip footing at a lower level etc.. if not then chances are the wall will go what just to slab top level which will be below the screed (75mm or so down - might encounter some insulation)

View media item 20998View media item 20999Could only find external wall details for a couple of common floor constructions but might help..
 

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