Bond Beam as Lintel - Typical Residential Application

[eng003]

I typically specify a double bond beam (two courses of cmu lintel block w/ continuous reinf.) at the top of all my exterior load bearing walls for residential structures. I like the lower course for giving more strength for uplift conditions in my high wind location. For wall openings I typical specify a precast lintel. Often I am required to put openings just below the double bond beam and sometimes below one course only so the single bond beam is acting as the lintel as well. In this situation, when I only have one course to work with I typically require a high strength precast lintel as the single bond beam course and continue the bond beam horizontal reinforcement through it but I still don't like it...


I am interested in how others typically detail CMU walls for typical residential applications?
-double vs. single bond beam?
-precast vs. lintel block vs. cast-in-place concrete beam?

 

[DST148]

@eng003 - We typically do multistory low-cost housing buildings with loadbearing masonry + precast plank. We use single bond beam below planks and 8" / 12" precast lintels over openings with projecting horizontal and vertical dowels.

 

[hokie66]

I reinforce the masonry as required rather than introducing precast elements.

 

[ron9876]

If you have large uplifts be sure that the wall reinforcement has enough developemnt. I am in a high wind area and use 16" deep bond beams for that reason.

 

[msquared48]

eng003:

Seems like the precast lintel might interfere with the CMU shearwall end vertical steel, as well as any chord steel required in the lintel/bond beam.

Does your precast element provide for the placement of grout and reinforcing within the precast element after it is in place?

Just curious...

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com