Opening on Existing CMU 2

[sigma1]

To support a new 24' long by 15' high opening on an existing CMU bearing wall (roof loads, wind, etc), we are using a WF steel beam and two WF steel columns. What is the best way to connect the steel beam and columns to the exiting CMU.

 

[JAE]

Are the columns and beam to sit inside the opening (i.e. within the thickness of the wall)???

If so - what would provide the makeup for the lost lateral resistance in the wall? The beam/column bent would laterally be braced by the wall at the opening edges and this would definitely overstress the CMU with a 24 foot opening.

 

[sigma1]

Yes. Withing the wall thickness. Also the columns would span from the concrete floor to the bond beam supporting the Steel Joist above.

 

[JAE]

So is there CMU above the beam? If so, how does the column extend above the opening?

 

[sigma1]

The old CMU above the beam would be removed and be reinstalled. Any other recommendations?

 

[JAE]

Column to wall:
Use steel straps on each face of the wall (assuming the wall is covered and you can get away with it) and bolt into the face of the wall each side with sleeve anchors or with Hilti HY 20 anchors.

Another detail is to use a WF just large enough to fit the flanges on each face of the adjacent wall, thus tying the two together.

Alternatively, you could use a channel instead of a WF for the column, with bolts going through the web into the end of the wall.

 

[haynewp]

Are you planning on removing the existing block up to the bond beam elevation only? Is there a parapet?

 

[sigma1]

There is no parapet above.

 

[haynewp]

What I have done before with WF lintels and cmu is to use like 16" long threaded rods welded to the top flange of the beam at the same spacing as the reinforced cells. Stacking the new cmu on top of the rods and grouting solid kind of gives a composite section between the beam and the cmu, and it also gives a good tie at the base of the block to the beam.