Steel beam design where brick wall is removed. 8

[BRENDANF]

I am opening up an existing 8" brick exterior wall to 16'-6" for a room addition. I need to keep the ceilings flush and the depth of the floor joists above is 9.25", so I am limited to about 9" for the new steel beam depth. I am figuring the load on the beam to be to be 2220 pounds/foot. The question is if I use A-50 steel instead of A-36 steel does the "E" number, 29,000,000 change between the 2 different grades of steel? I am having problems with deflection--l/600 for masonry.

 

[KootK]

You can probably do one sided arching if you've got some meat on that side of your opening.

I've used a slick detail using two channels. Place on on either side of the brick above the opening, through bolt them together, and connect the bottom flanges with a steel plate (continuous or intermittent). That way you don't use up any soffit depth.

Of course, the channels will be exposed to view so you'll need architectural approval for that. You might also neeed to find a way to deal with water migrating in from outsite. I think it looks cool. I'm hardly impartial though...

 

[ronster]

You can not have arching on one side of the beam. Arching causes an equal lateral outward thrust on both sides over the opening. You need masonry beyond the opening on both sides to resist it. Also any windows could interfere with arching. I would not depend on arching on such a large opening at the end of a wall.

I often use the double channel Adam suggested. If you cut a horizontal groove into the the brick you can turn the channel leg in towards the wall into the cut and have the channel directly support the wall without need for shoring.

Make sure you alert the architect to the water problem as it will be a problem.

 

[civilperson]

RCraine:
The OP said the depth limit comes from ceiling depth, no width limit is required when the wall is removed below as long as there is support for the extra width at the ends. Two W8 beams with a common plate across the top is what I envisioned for a shallow support with twice the moment of inertia of one W8.

 

[PEinVA]

You are correct, civilperson.

This is why after I stated it wouldn't fit if pocketed, etc. I questioned how it was to be connected. I would imagine the width would be somewhat constrained by the width of the wall if the beams are spanning due to existing framing in the structure, just my guess though.

Hopefully BRENDANF has resolved his issues.

What did you end up doing BRENDANF?

RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

 

[msquared48]

CSD:

We have "special" beams here... They are able to take a lot of "stress", so they do have feelings. Also, they do get tend to get torqued about a lot of the pressures they experience. Nebvertheless, it's shear ecstasy for them.

Mike McCann
MMC Engineering

 

[BRENDANF]

I took the new flat roof load and the floor load off the beam.

I planning using a W8x48 with at 1/2" steel plate welded to the bottom of the beam.

Thanks for your help!

 

[mcaulfield]

I am designing a lentil beam system to produce a 40 foot opening 8 feet high in an existing brick wall in an ancient retail store. Will support the 40 foot hole with columns on 10 foot centers.

I plan to use double 8X6X1/2 angles with the 6 inch leg cut in the existing wall on either side and then through bolt the vertical legs on 2.5 foot centers.

Question - I see references to channels being used for this purpose but not many about angles. Is there experience out there using angles?? Thanks

 

[PEinVA]

mcaulfield,
have you thought of possibly, after the brick is removed from below, coming back and adding a plate across the seam of the angles so it will act as a single lintel.

Through bolting seems that it would damage the brick/block right above the lintel and that doesn't seem like a very good idea. Our typical details are for what I mentioned above. We've used it it many applications.

Hope that helps.


RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke